CN114172391B - Constant power reference modulation circuit, control device and chip, power supply device and method - Google Patents

Abstract

Translated fromChinese

本申请公开一种恒功率基准调制电路、控制装置及芯片、电源装置及方法。所述恒功率基准调制电路配置于一电源装置中，所述恒功率基准调制电路包括第一采样端、以及基准调制单元。所述第一采样端用于接收反映负载电压的第一采样信号；所述基准调制单元耦接于所述第一采样端，用于将所述第一采样信号转换为恒功率基准信号；其中，所述恒功率基准信号随着所述第一采样信号的变化呈相反变化；在所述恒功率基准信号的作用下，所述电源装置输出的供电功率维持在一稳定功率。

The present application discloses a constant power reference modulation circuit, a control device and a chip, a power supply device and a method. The constant power reference modulation circuit is configured in a power supply device, and the constant power reference modulation circuit includes a first sampling terminal and a reference modulation unit. The first sampling terminal is used to receive a first sampling signal reflecting the load voltage; the reference modulation unit is coupled to the first sampling terminal and is used to convert the first sampling signal into a constant power reference signal; wherein the constant power reference signal changes in the opposite direction to the change of the first sampling signal; under the action of the constant power reference signal, the power supply output by the power supply device is maintained at a stable power.

Description

Constant power reference modulation circuit, control device, chip, power supply device and method

Technical Field

The present application relates to the field of control circuits, and in particular, to a constant power reference modulation circuit, a control device, a chip, a power supply device, and a method.

Background

The switching power supply is equipment for converting electric energy, can convert alternating current provided by a power grid into direct current of each path to be output for supplying power to loads, has the advantages of fewer peripheral system components, low cost, simple structure, low standby power consumption and the like, and is widely applied to power adapters of various loads.

However, with the progress of technology, higher demands are made on the functions that the load can provide, so that the switching power supply is forced to provide diversified output power supply modes to adapt to the demands of the load. For example, for mobile electronic devices, the update speed is fast, and the current charging mode has been increased from the original normal charging mode to the fast charging mode, so that compared with the technical upgrade of the mobile electronic device, the technology of a switching power supply matched with the mobile electronic device actually has higher requirements. The switching power supply is required to meet the power supply requirement of the load, and meanwhile, a mode of supplying power to the load is reasonably designed so as to avoid damage to the load or energy waste.

Disclosure of Invention

In view of the above-mentioned problems that the related art cannot reasonably provide a suitable load power supply mode according to the power supply requirement of the load, and energy waste or load damage is caused, the present application aims to provide a constant power reference modulation circuit, a control device, a chip, a power supply device and a method.

To achieve the above and other related objects, a first aspect of the present application discloses a constant power reference modulation circuit configured in a power supply device, where the constant power reference modulation circuit includes a first sampling end for receiving a first sampling signal reflecting a load voltage, and a reference modulation unit coupled to the first sampling end for converting the first sampling signal into a constant power reference signal, where the constant power reference signal varies inversely with a variation of the first sampling signal, and a power supply output by the power supply device is maintained at a stable power under the action of the constant power reference signal.

In some embodiments of the disclosure in the first aspect of the present application, the constant power reference signal and the first sampling signal have opposite multi-segment changing relationships, where a product of the constant power reference signal and the first sampling signal corresponding to each segment endpoint is a fixed value.

In certain embodiments of the disclosure of the first aspect of the application, the constant power reference signal is in an inverse multi-segment linear relationship with the first sampled signal.

In some embodiments of the disclosure, the power supply device further includes a demagnetizing sampling unit coupled between the first sampling end and the reference modulation unit, for outputting the first sampling signal to the reference modulation unit when detecting that the power conversion circuit in the power supply device is in a demagnetizing stage.

In some embodiments of the disclosure, the demagnetizing sampling unit includes a demagnetizing detection circuit coupled to the first sampling end for detecting the first sampling signal to output a demagnetizing detection signal when the power conversion circuit is in a demagnetizing stage, and a demagnetizing sampling circuit coupled to the demagnetizing detection circuit for outputting the first sampling signal when the demagnetizing detection signal is received.

In certain embodiments of the disclosure, the reference modulation unit comprises a constant power reference generation circuit for outputting a constant power reference signal based on a reference signal output by a reference power supply, and a signal adjustment circuit coupled to the first sampling terminal and the constant power reference generation circuit and receiving at least one threshold signal for adjusting a circuit characteristic of the constant power reference generation circuit according to a signal variation of the first sampling signal relative to the threshold signal, such that the output constant power reference signal varies inversely with the variation of the first sampling signal.

In certain embodiments of the disclosure, the signal conditioning circuit comprises a current branch connected to the constant power reference generating circuit, at least one current converting circuit having an input receiving the first sampling signal and another input receiving the threshold signal, and an output coupled to the current branch for conditioning the current signal in the current branch based on a signal difference between the first sampling signal and the threshold signal. Wherein the threshold signals received by the different current conversion circuits are different.

In some embodiments of the disclosure, the signal conditioning circuit includes at least two current conversion circuits, and the signal conditioning circuit further includes at least one current limiting circuit coupled to one of the current conversion circuits for limiting the current signal output by the current conversion circuit coupled to the first sampling signal to a fixed current signal when the first sampling signal reaches the threshold signal received by the other current conversion circuit, so that the current signal in the current branch is changed along with the current signal output by the other current conversion circuit.

In some embodiments disclosed in the first aspect of the present application, the at least two current conversion circuits are a first current conversion circuit and a second current conversion circuit, and the current limiting circuit includes a first selection circuit, one input end of which receives the first sampling signal, the other input end of which receives the second threshold signal, and an output end of which is coupled to the first current conversion circuit and is used for outputting the first sampling signal or the second threshold signal, wherein the first current conversion circuit outputs the fixed current signal based on a signal difference between the second threshold signal and the first threshold signal, and the fixed current signal and the current signal output by the second current conversion circuit based on a signal difference between the first sampling signal and the second threshold signal are combined into the current signal in the current branch, and the first threshold signal corresponds to the threshold signal received by the first current conversion circuit, and the second threshold signal corresponds to the threshold signal received by the second current conversion circuit.

In certain embodiments of the disclosure of the first aspect of the application, the constant power reference generation circuit comprises an output resistor, one end of which is used for acquiring the reference signal, and the other end of which is coupled with the signal conditioning circuit and is used for outputting the constant power reference signal.

The second aspect of the application discloses a control device of a switching device, which comprises a second sampling end, a third sampling end, a constant power reference signal generating unit and a mode selecting unit, wherein the second sampling end is used for acquiring a second sampling signal reflecting peak current of a power conversion circuit, the power conversion circuit is coupled with the switching device, the third sampling end is used for acquiring a third sampling signal reflecting load current, the constant power reference signal generating unit is coupled with the second sampling end and comprises any constant power reference modulating circuit disclosed in the first aspect of the application, the constant power reference modulating circuit is used for outputting a constant power reference signal based on the second sampling signal and the constant power reference signal, the mode selecting unit is coupled with the third sampling end and the constant power reference generating unit and is used for selectively outputting the constant power reference signal or outputting the third sampling signal as a constant voltage reference signal, and the switching control unit is coupled with the mode selecting unit and is used for controlling the switching device under the action of the constant voltage reference signal so that the power supply voltage output by the power conversion circuit is maintained at a stable voltage or the constant power reference signal is controlled under the action of the constant power reference signal so that the power conversion circuit is maintained at a stable power supply voltage.

In some embodiments of the disclosure, the constant power reference signal and the first sampling signal have opposite multi-stage changing relation, and each stage endpoint corresponds to the power supply output by the power conversion circuit and maintains the constant power.

In some embodiments disclosed in the second aspect of the present application, the mode selection unit includes a comparison circuit coupled to the third sampling terminal and the constant power reference signal generation unit, for outputting a high level signal when the third sampling signal is determined to be less than a first load threshold so that the constant power reference signal is forced to be the high level signal, and a selection circuit coupled to the third sampling terminal and the constant power reference signal generation unit, for selectively outputting the constant power reference signal or outputting the third sampling signal as a constant voltage reference signal based on a magnitude relation of the received signals.

In some embodiments of the second aspect of the present application, the mode selection unit further receives a constant current reference signal, and is configured to selectively output the constant current reference signal, and under the action of the constant current reference signal, the supply current output by the power conversion circuit is maintained at a stable current.

In some embodiments of the second aspect of the present application, the switch control unit includes a turn-off detection circuit, coupled to the mode selection unit and the second sampling terminal, for outputting a turn-off signal when the second sampling signal reaches one of the reference signals output by the mode selection unit, so as to turn off the switching device.

In certain embodiments of the second aspect of the present application, the switch control unit further comprises a conduction detection circuit for outputting a conduction signal to turn on the switching device.

In certain embodiments of the second aspect of the present disclosure, the switch control unit further comprises:

and the driving circuit is coupled with the on detection circuit and the off detection circuit and is used for outputting a driving signal based on the on signal and the off signal so as to control the on or off of the switching device.

A third aspect of the present application discloses a power supply apparatus including a rectifying circuit for receiving an external driving signal to output a rectifying signal, a filter circuit coupled to the rectifying circuit for filtering the rectifying signal to output a filtering signal, a control device as any one of the second aspects of the present application for outputting a driving signal based on a first sampling signal, a second sampling signal, and a third sampling signal, a switching device having a control terminal coupled to the control device for turning on or off based on the driving signal, a power conversion circuit coupled to the switching device and the filter circuit for energy converting the filtering signal to output a constant voltage power supply or a constant power supply to a load based on the turning on or off of the switching device, and a sampling circuit coupled to the control device and the power conversion circuit for sampling an electric signal reflecting a load voltage, a load current, and a peak current of the power conversion circuit to output the first sampling signal, the third sampling signal, and the second sampling signal to the control device.

The fourth aspect of the application discloses a constant power reference modulation method which comprises the steps of receiving a first sampling signal reflecting load voltage, and converting the first sampling signal into a constant power reference signal, wherein the constant power reference signal changes inversely with the change of the first sampling signal.

In some embodiments of the fourth aspect of the present application, the constant power reference signal and the first sampling signal have opposite multi-segment changing relationships, where a product of the constant power reference signal and the first sampling signal corresponding to each segment endpoint is a fixed value.

In certain embodiments of the fourth aspect of the present application, the constant power reference signal is in an inverse multi-segment linear relationship with the first sampled signal.

The fifth aspect of the application discloses a control method of a switching device, which comprises the steps of obtaining a second sampling signal reflecting peak current of a power conversion circuit and a third sampling signal reflecting load current, wherein the power conversion circuit is coupled with the switching device, converting a first sampling signal into a constant power reference signal by adopting any constant power reference modulation method disclosed in the fourth aspect of the application, outputting a constant power reference signal based on the second sampling signal and the constant power reference signal, selectively outputting the constant power reference signal or outputting the third sampling signal as a constant voltage reference signal, and controlling the switching device under the action of the constant voltage reference signal so that the power supply voltage output by the power conversion circuit is maintained at a stable voltage, or controlling the switching device under the action of the constant power reference signal so that the power supply power output by the power conversion circuit is maintained at a stable power.

In some embodiments of the fifth aspect of the present application, the method further comprises the steps of obtaining a constant current reference signal, selectively outputting the constant current reference signal, and maintaining the supply current output by the power conversion circuit at a stable current under the action of the constant current reference signal.

A sixth aspect of the application discloses a control chip packaged with a constant power reference modulation circuit as disclosed in any of the first aspects of the application or with a control device as disclosed in any of the second aspects of the application.

In summary, the constant power reference modulation circuit, the control device, the chip, the power supply device and the method disclosed by the application can provide different power supplies according to different load capacities, so that when the load is supplied with power, the load can be quickly in a high-power supply stage, and the energy utilization rate is improved.

Drawings

The specific features of the application related to the application are shown in the appended claims. A better understanding of the features and advantages of the application in accordance with the present application will be obtained by reference to the exemplary embodiments and the accompanying drawings that are described in detail below. The brief description of the drawings is as follows:

fig. 1 shows a circuit block diagram of a power supply device according to an embodiment of the application.

Fig. 2 is a schematic circuit diagram of a rectifying circuit according to an embodiment of the application.

Fig. 3 is a schematic circuit diagram of a filter circuit according to an embodiment of the application.

Fig. 4 is a circuit block diagram of a power conversion device according to an embodiment of the application.

Fig. 5 is a schematic circuit diagram of a power conversion device according to an embodiment of the application.

Fig. 6 shows a circuit block diagram of a control device according to an embodiment of the application.

Fig. 7 is a circuit block diagram of a constant power reference generating unit in an embodiment of the application.

Fig. 8 is a schematic diagram showing an input-output relationship of the reference modulation unit according to an embodiment of the application.

Fig. 9 is a schematic diagram showing the input-output relationship of the reference modulation unit according to another embodiment of the present application.

Fig. 10 is a circuit block diagram of a reference modulation unit in an embodiment of the application.

Fig. 11 is a schematic circuit diagram of a constant power reference generating circuit according to an embodiment of the application.

Fig. 12 is a schematic circuit diagram of a constant power reference generating circuit according to another embodiment of the present application.

Fig. 13 is a circuit block diagram of a signal conditioning circuit according to an embodiment of the present application.

Fig. 14 is a circuit block diagram of a signal conditioning circuit in another embodiment of the present application.

Fig. 15 is a schematic diagram showing an input-output relationship of a signal conditioning circuit according to another embodiment of the application.

Fig. 16 shows a circuit block diagram of a constant power reference modulation circuit in an embodiment of the application.

Fig. 17 is a schematic circuit diagram of a demagnetizing sampling unit according to an embodiment of the present application.

Fig. 18 is a circuit block diagram of a mode selection unit according to an embodiment of the present application.

Fig. 19 is a circuit block diagram of a switch control unit according to an embodiment of the present application.

FIG. 20 is a schematic diagram showing the power supply device supplying power to the load output in one embodiment of the application

Detailed Description

Further advantages and effects of the present application will become apparent to those skilled in the art from the disclosure of the present application, which is described by the following specific examples.

In the following description, reference is made to the accompanying drawings which describe several embodiments of the application. It is to be understood that other embodiments may be utilized and that mechanical, structural, electrical, and operational changes may be made without departing from the spirit and scope of the present disclosure. The following detailed description is not to be taken in a limiting sense, and the scope of embodiments of the present application is defined only by the claims of the issued patent. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. Spatially relative terms, such as "upper," "lower," "left," "right," "lower," "upper," and the like, may be used herein to facilitate a description of one element or feature as illustrated in the figures as being related to another element or feature.

Although the terms first, second, etc. may be used herein to describe various elements or parameters in some examples, these elements or parameters should not be limited by these terms. These terms are only used to distinguish one element or parameter from another element or parameter. For example, a first sampled signal may be referred to as a second sampled signal, and similarly, a second sampled signal may be referred to as a first sampled signal, without departing from the scope of the various described embodiments. The first and second sampled signals are both described as one sampled signal, but they are not the same sampled signal unless the context clearly indicates otherwise. Similar situations also include the first current conversion circuit and the second current conversion circuit, or the first threshold signal and the second threshold signal.

Furthermore, as used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context indicates otherwise. It will be further understood that the terms "comprises," "comprising," "includes," and/or "including" specify the presence of stated features, steps, operations, elements, components, items, categories, and/or groups, but do not preclude the presence, presence or addition of one or more other features, steps, operations, elements, components, items, categories, and/or groups. The terms "or" and/or "as used herein are to be construed as inclusive, or meaning any one or any combination. Thus, "A, B or C" or "A, B and/or C" means "any of A, B, C, A and B, A and C, B and C, A, B and C". An exception to this definition will occur only when a combination of elements, functions, steps or operations are in some way inherently mutually exclusive.

In addition, it should be noted that, in order to clearly describe each of the features of the present application, the following description is given with respect to each embodiment by way of example, but it does not mean that each embodiment can be implemented solely. Those skilled in the art will readily adapt the present application to the specific design requirements of the specific implementation, or will be able to adapt the present application to different design requirements. In other words, the implementation of the present teachings is not limited to the embodiments described below, but includes substitution and arrangement of various embodiments/components/modules where possible, as described earlier.

In order to match the power supply of various loads such as an electronic terminal, a display, a server, mobile electronic equipment, various instruments and meters and the like, the alternating current provided by a power grid is generally converted into direct current output suitable for various loads through a switching power supply. The switching power supply pair needs to provide a diversified power supply manner during power supply to the load, affected by, for example, a relationship between an electrical characteristic of the load itself and a change in a power supply signal, and/or a relationship between a change in electric charge required by the load and a required power supply signal. For example, in the case of an LED device, the temperature rise of the LED device causes a rapid change in current, so that a switching power supply for supplying power to the LED device needs to be designed as a power adapter capable of providing a constant current power supply mode and a constant voltage power supply mode to prevent the LED device from being over-flowed, thereby affecting the life of the LED device. For another example, for an electronic device including a battery, in order to implement quick charging of the electronic device, a charger including a switching power supply is designed to be capable of providing a constant current power supply mode and a constant voltage power supply mode, and in an initial stage, the electronic device is quickly charged with a large current provided by the constant current power supply mode to a charge cutoff threshold value (typically set to 70% of the total electric quantity of the battery) in a first stage, and then is subjected to constant voltage charging according to a voltage corresponding to the charge cutoff threshold value until current attenuation is lower than the charge cutoff threshold value (typically set to 100% of the total electric quantity of the battery) in a second stage.

However, with the increasing battery capacity of electronic devices and the increasing demand for charging speed, the power demand for chargers is also increasing, and although the power may be increased by further increasing the charging current, this is not desirable due to the limitation of the charging wire and the cost. The other way is to boost the power by boosting the charging voltage, at this time, the output voltage of the charger is higher, and if the charging current allowed by the charging wire is still used for charging, the output power of the charger is far higher than the requirement of the battery, so that energy waste is caused, and in addition, the volume and the cost of the charger are increased.

In view of this, in a possible embodiment, the present application provides a power supply apparatus capable of outputting constant voltage power supply or constant power supply to a load, thereby satisfying the load having a constant power supply demand, and further, when the power supply apparatus is adopted to supply power to the load, capable of flexibly adjusting an output current according to an output voltage of the power supply apparatus, so that the load is quickly in a high power supply stage, thereby improving an energy utilization rate.

Referring to fig. 1, a circuit block diagram of a power supply device according to an embodiment of the application is shown, and the power supply device 10 includes a rectifying circuit 11, a filtering circuit 12, and a power supply device 13. The rectifying circuit 11 is coupled to the first pin p_11 and the second pin p_12. The filter circuit 12 is coupled to the rectifying circuit 11 through a first rectifying output terminal p_13 and a second rectifying output terminal p_14. The power supply device 13 is coupled to the filter circuit 12 via a first filter output terminal p_15 and a second filter output terminal p_16.

The rectifying circuit 11 receives an external driving signal from the first pin p_11 and the second pin p_12, and rectifies the external driving signal to output a rectified signal. The external driving signal may be, for example, an alternating current signal output by a utility grid, or may be, for example, a direct current signal output by an emergency power supply. The rectifier circuit 11 may be, for example, a full-wave rectifier circuit or a half-wave rectifier circuit formed using electronic components such as diodes.

Referring to fig. 2, a schematic circuit diagram of a rectifying circuit according to an embodiment of the application is shown, and the rectifying circuit 11 includes diodes D1 to D4 as shown. The anode of the diode D1 is coupled to the first pin p_11, and the cathode is coupled to the cathode of the diode D2. The cathode of the diode D2 is coupled to the first rectifying output terminal p_13, and the anode is coupled to the cathode of the diode D3. The cathode of the diode D3 is coupled to the second pin p_12, and the anode is coupled to the second rectifying output terminal p_14. The anode of the diode D4 is coupled to the second rectifying output terminal p_14, and the cathode is coupled to the first pin p_11.

When the signals received by the first pin p_11 and the second pin p_12 are ac signals, the operation of the rectifying circuit 11 is described as follows. When the ac signal is in the positive half wave, the ac signal flows in after passing through the first pin p_11, the diode D1 and the first rectifying output terminal p_13 in sequence, and flows out after passing through the second rectifying output terminal p_14, the diode D3 and the second pin p_12 in sequence. When the ac signal is in the negative half wave, the ac signal flows in after passing through the second pin p_12, the diode D2 and the first rectifying output terminal p_13 in sequence, and flows out after passing through the second rectifying output terminal p_14, the diode D4 and the first pin p_11 in sequence. Therefore, no matter the ac signal is in the positive half-wave or the negative half-wave, the positive electrode of the rectified signal of the rectifying circuit 11 is located at the first rectifying output terminal p_13, and the negative electrode is located at the second rectifying output terminal p_14. According to the above description, the rectified signal output from the rectifying circuit 11 is a full-wave rectified signal.

When the first pin p_11 and the second pin p_12 are coupled to the dc power source to receive the dc signal, the operation of the rectifying circuit 11 is described as follows. When the first pin p_11 is coupled to the positive terminal of the dc power supply and the second pin p_12 is coupled to the negative terminal of the dc power supply, the dc signal flows in after passing through the first pin p_11, the diode D1 and the first rectifying output terminal p_13 in sequence, and flows out after passing through the second rectifying output terminal p_14, the diode D3 and the second pin p_12 in sequence. When the first pin p_11 is coupled to the negative terminal of the dc power supply and the second pin p_12 is coupled to the positive terminal of the dc power supply, the dc signal flows in after passing through the second pin p_12, the diode D2 and the first rectifying output terminal p_13 in sequence, and flows out after passing through the second rectifying output terminal p_14, the diode D4 and the first pin p_11 in sequence. Similarly, no matter how the dc signal is input through the first pin p_11 and the second pin p_12, the positive poles of the rectified signals of the rectifying circuit 11 are all located at the first rectifying output terminal p_13, and the negative poles are all located at the second rectifying output terminal p_14. Therefore, the rectifying circuit 11 in the present embodiment can correctly output the rectified signal regardless of whether the received signal is an ac signal or a dc signal.

The filter circuit 12 receives the rectified signals output from the first rectified output terminal p_13 and the second rectified output terminal p_14, and is configured to filter the rectified signals to output a filtered signal. The filter circuit 12 may be a pi-type filter circuit, an LC-type filter circuit, an RC-type filter circuit, an LC pi-type filter circuit, an RC pi-type filter circuit, or the like, which is not limited in the present application.

Referring to fig. 3, a schematic circuit diagram of a filter circuit according to an embodiment of the application is shown, and the filter circuit 12 includes a filter capacitor C1. One end of the filter capacitor C1 is coupled to the first rectifying output end p_13 and the first filtering output end p_15, and the other end is coupled to the second rectifying output end p_14 and the second filtering output end p_16, so as to perform low-pass filtering on the rectified signals output by the first rectifying output end p_13 and the second rectifying output end p_14, so as to filter out high-frequency components in the rectified signals to form a filtered signal, and then the filtered signal is output by the first filtering output end p_15 and the second filtering output end p_16.

The power conversion device is used for outputting different power supplies, such as constant voltage power supply or constant power supply, to the load based on the filtered signal and the load side power supply condition.

Referring to fig. 4, a circuit block diagram of a power conversion apparatus according to an embodiment of the application is shown, and the power conversion apparatus 13 includes a control apparatus 20, a switching device 30, a sampling circuit 50, and a power conversion circuit 40. The control device 20 is coupled to a control terminal of the switching device 30, and is configured to output a driving signal to control on or off of the switching device 30 based on the first sampling signal, the second sampling signal, and the third sampling signal. The power conversion circuit 40 is coupled to the switching device 30, and is coupled to the first filtering output terminal p_15 and the second filtering output terminal p_16 to receive the filtering signal, and performs energy conversion on the filtering signal based on or off of the switching device 30 to output constant voltage power to the load by the first power output terminal p_17 and the second power output terminal p_17 thereof during a period when the load current is smaller than the first preset current, output constant power to the load during a period when the load current is larger than the first preset current and smaller than the second preset current, and output constant current power to the load during a period when the load current reaches the second preset current. The sampling circuit 50 is coupled to the power conversion circuit 40 and the control device 20, and is configured to sample the load voltage, the load current, and the peak current of the power conversion circuit, respectively, so as to correspondingly output a first sampling signal reflecting the load voltage, a third sampling signal reflecting the load current, and a second sampling signal reflecting the peak current of the power conversion circuit to the control device 20.

The switching device is a three-terminal controllable device which can be controlled to be turned on and turned off by a driving signal, and comprises a control end, a first end and a second end, wherein the control end controls the on or off between the first end and the second end based on the received driving signal. The three-terminal controllable device includes a controllable transistor, which may be, for example, a Metal-oxide-semiconductor field effect transistor (MOSFET) or a bipolar junction transistor (Bipolar Junction Transistor, BJT), etc.

The power conversion circuit refers to a direct current-direct current conversion circuit capable of converting electric energy based on and off of a switching device to convert one received direct current into another direct current, wherein one and the other direct current are different in electric energy characteristics, for example, current magnitude, voltage magnitude, or power value, representing the two direct currents. In a specific embodiment, the power conversion circuit comprises an isolated or non-isolated DC-DC converter circuit. The non-isolated DC-DC converter circuit includes, but is not limited to, a Buck circuit, a Boost circuit, a Cuk circuit, a Sepic circuit, or a Zata circuit. The isolated DC-DC converter circuit includes, but is not limited to, a forward circuit or a flyback circuit.

The sampling circuit is coupled between the power conversion circuit and the control device to output the three sampling signals. In this embodiment, the sampling circuit includes a first sampling circuit, a second sampling circuit, and a third sampling circuit.

The first sampling circuit obtains an electric signal reflecting the load voltage output by the power conversion circuit by using components, such as an induction device, a shunt voltage divider device and the like, capable of obtaining the electric signal of the load voltage, so as to output a first sampling signal. For example, the first sampling circuit is disposed between two output terminals of the power conversion circuit, and has an output terminal for outputting a first sampling signal. Wherein the first sampling circuit comprises a plurality of resistive devices, such as a plurality of series resistors, connected in series. For another example, the first sampling circuit is coupled to the inductive device of the power conversion circuit to sense the power output by the power conversion circuit, and has an output terminal for outputting the first sampling signal. The first sampling circuit comprises an inductor, a resistor connected with the inductor and the like.

The second sampling signal obtains an electric signal reflecting the peak current of the power conversion circuit by using components such as a resistor, a capacitor and the like, so as to output the second sampling signal. For example, the second sampling circuit is connected in series to the line where the switching device is located, and has an output terminal for outputting a second sampling signal. The second sampling signal comprises a resistor and the like and is used for sampling peak current of the power conversion circuit when the switching tube is conducted, so that the second sampling signal is output.

The third sampling circuit obtains an electric signal reflecting the load current output by the power conversion circuit by using sampling devices such as an induction device, a photoelectric conversion device, a shunt voltage division device and the like, so as to output a third sampling signal. For example, the third sampling circuit is disposed between two output terminals of the power conversion circuit, and has an output terminal for outputting a third sampling signal. Wherein the third sampling circuit includes a photoelectric conversion device and the like.

The sampling circuits can select the adaptive circuit structure based on different kinds of the configured power conversion circuits, and the structural form of the sampling circuit is not limited. For example, part of circuit devices in the sampling circuit are shared, and the sampling circuit further comprises a sampling control circuit which outputs different sampling signals by controlling sampling timing and utilizing the shared part of circuit devices.

The power conversion device shown in fig. 5 is used as an example to explain the operation principle, wherein the specific circuit and operation principle of the control device are described in detail in fig. 6 to 19. Referring to fig. 5, a schematic circuit diagram of a power conversion apparatus according to an embodiment of the application is shown, and as shown in the drawing, the power conversion apparatus 13 includes a control device 20, a switching device 30, a sampling circuit 50, and a power conversion circuit 40. The control device 20 includes a control chip 21 and peripheral circuits adapted to the control chip 21, and the peripheral circuits will vary according to the specific embodiment and the circuit module packaged inside the control chip 21, so that the control device 20 mentioned in the following embodiments will not be described again. The control chip 21 includes a power supply terminal Vcc, a ground terminal Gnd, a first sampling terminal Det, a second sampling terminal Cs, a third sampling terminal Fb, and an output terminal Drv. The power supply end Vcc is coupled to a peripheral power supply circuit comprising a resistor R3 and a capacitor C3 to obtain a power supply, and specifically, one end of the resistor R3 is coupled to the first filter output end p_15, the other end is coupled to one end of the capacitor C3 and is coupled to the power supply end Vcc, and the other end of the capacitor C3 is coupled to the second filter output end p_16. The ground Gnd is connected to the second filter output p_16. The first sampling end Det, the second sampling end Cs, and the third sampling end Fb are connected to the sampling circuit 50. The output terminal Drv is connected to a control terminal of the switching device 30.

The power conversion circuit 40 includes a transformer T, a diode D5, and an output capacitor C2, where the transformer T is a flyback transformer, and includes a primary winding Np and a secondary winding Ns, the synonym end of the primary winding Np is coupled to the first filtering output end p_15, the synonym end of the secondary winding Ns is coupled to the first end of the switching device 30, the synonym end of the secondary winding Ns is coupled to the second power output end p_18, the synonym end is coupled to the anode of the diode D5, the cathode of the diode D5 is coupled to the first power output end p_17, and the output capacitor C2 is connected in parallel between the first power output end and the second power output end for stabilizing the output power supply signal.

The sampling circuit 50 includes a first sampling circuit 51, a second sampling circuit 52, and a third sampling circuit 53. The first sampling circuit 51 includes an auxiliary winding Na wound around the primary side of the transformer T, a diode D6, a resistor R1, and a resistor R2, where the homonymous terminal of the auxiliary winding Na is coupled to the anode of the diode D6, the heteronymous terminal is coupled to the second filtering output terminal p_16, the cathode of the diode D6 is coupled to the other end of the resistor R3, the resistor R1 and the resistor R2 are connected in series between the homonymous terminal of the auxiliary winding Na and the second filtering output terminal p_16, and the connection terminals of the resistor R1 and the resistor R2 are coupled to the first sampling terminal Det of the control chip 21. The second sampling circuit 52 includes resistors R4 and R5, and a capacitor C4, where one end of the resistor R4 is connected to one end of the resistor R5 and to the second end of the switching device 30, the other end is coupled to the second filtering output p_16, the other end of the resistor R5 is connected to the second sampling end Cs of the control chip 21, and the capacitor C4 is optionally omitted and is connected between the other end of the resistor R5 and the second filtering output p_16. The third sampling circuit 53 includes an output resistor R6, a light emitting diode D7, a phototransistor Q1 (the light emitting diode D7 and the phototransistor Q1 may be also referred to as an optocoupler), and a zener diode D8, wherein one end of the output resistor R6 is coupled to the first power output terminal p_17, the other end is coupled to the anode of the light emitting diode D7, the cathode of the light emitting diode D7 is coupled to the cathode of the zener diode D8, the anode of the zener diode D8 is connected to the second power output terminal p_18, and the phototransistor Q1 is connected between the first filtering output terminal p_16 and the third sampling terminal Fb of the control chip 21. In this embodiment, the first sampling circuit 51 feeds back the first sampling signal reflecting the load voltage to the control device 20 by sampling on the primary side, so that the third sampling circuit 52 can feed back the third sampling signal reflecting the load current to the control device 20 by setting an optocoupler on the secondary side.

The power supply device shown in fig. 5 operates on the principle that when the switching device 30 is turned on, the primary winding Np of the transformer T stores energy, and the second sampling circuit 52 obtains the current flowing through the switching device 30 to output a second sampling signal reflecting the peak current of the transformer T to the second sampling terminal Cs. When the switching device 30 is turned off, energy in the transformer T is discharged to the third sampling circuit 53 and supplied to the load side through the secondary winding Ns and the diode D5, and a first sampling signal reflecting the load voltage is output to the first sampling terminal Det through the first sampling circuit 51, the third sampling circuit 53, and the light emitting diode D7 in the third sampling circuit 53 is configured to detect the load current to emit light intensity in a positive change relation with the current intensity, such as when the load current is large, its light emission luminance is high, so that the third sampling signal converted to reflecting the load current is sensed by the phototransistor Q1 to the third sampling terminal Fb. The control device 20 thus generates a driving signal for controlling the timing of turning on or off the switching device 30 by performing detection processing and/or signal modulation processing based on the first, second, and third sampling signals, and outputs the driving signal to the switching device 30, thereby causing the timing of storing and releasing energy of the power conversion circuit 40 to be changed to output power required by a load to the load.

Specifically, referring to fig. 20, a schematic diagram of the power supply device for supplying power to the load output according to an embodiment of the present application is shown, wherein an abscissa I represents the output current and an ordinate V represents the output voltage. During the control of the control device 20, it controls the switching device 30 to make the power conversion circuit 40 output constant voltage power supply, constant power supply, or constant current power supply using the first sampling signal, the second sampling signal, and the third sampling signal. Further, in the case that the load is a light load, as in the stage of load current I < I1 in fig. 20, the control device 20 controls the switching device 30 to be turned off based on the second sampling signal and the first sampling signal, and controls the switching device 30 to be turned on based on at least one signal of the first sampling signal, the second sampling signal and the third sampling signal or the fixed PWM pulse signal, so that the power conversion circuit 40 outputs constant voltage power supply. In the case that the load is heavy, as in the stage of load current I > I1 in fig. 20, the control device 20 controls the switching device 30 to be turned off based on the second sampling signal and the third sampling signal, and controls the switching device 30 to be turned on based on at least one signal of the first sampling signal, the second sampling signal and the third sampling signal or the fixed PWM pulse signal, so that the power conversion circuit 40 outputs constant power supply. In the case that the load is overweight, as in the stage of load current I > I2 in fig. 20, the control device 20 controls the switching device 30 to be turned off based on the second sampling signal, and controls the switching device 30 to be turned on based on at least one signal of the first sampling signal, the second sampling signal, and the third sampling signal or the fixed PWM pulse signal, so that the power conversion circuit 40 outputs constant current power supply. Taking a load as an example of mobile electronic equipment, in an initial charging stage, the charge amount stored in a battery is small, the load is in a heavy load condition, a charging current is larger than I1 and smaller than I2, a power supply device charges the battery in a constant power supply mode, the stored charge amount of the battery is continuously increased, the charging current is continuously reduced, and when the battery is charged to about seventy percent of the total electric quantity of the battery, the charging current is reduced to be lower than I1, and the power supply device charges the battery in a constant voltage supply mode.

Referring to fig. 6, a circuit block diagram of a control device according to an embodiment of the application is shown in fig. 6, and the control device 40 includes a first sampling terminal p_41, a second sampling terminal p_42, a third sampling terminal p_43, and an output terminal p_44, where the first sampling terminal p_41 is used for acquiring the first sampling signal, the second sampling terminal p_42 is used for acquiring the second sampling signal, the third sampling terminal p_43 is used for acquiring the third sampling signal, and the output terminal p_44 is used for outputting a driving signal. The control device 40 further comprises a constant power reference generation unit 41, a mode selection unit 42, and a switch control unit 43. The constant power reference generating unit 41 is coupled to the first sampling terminal p_41 and the second sampling terminal p_42, and is configured to generate a constant power reference signal based on the first sampling signal and the second sampling signal and output the constant power reference signal to the mode selecting unit 42 through an output terminal p_45 thereof. The mode selection unit 42 is connected to the output terminal p_45 and the third sampling terminal p_43 of the constant power reference generation unit 41, and receives a constant current reference signal cc_com for selectively outputting the constant power reference signal or outputting the constant current reference signal cc_com or outputting the third sampling signal as a constant voltage reference signal, and outputs the constant current reference signal cc_com to the switch control unit 43 through the output terminal p_46 thereof. The switch control unit 43 is connected to the output terminal p_46 of the mode selection unit 42 and the second sampling terminal p_42, and is configured to output a driving signal based on the signal output by the mode selection unit 42 and the second sampling signal to control on or off of the switching device, so that the power conversion circuit outputs a power supply of a corresponding mode. Specifically, the switching device is controlled under the action of the constant voltage reference signal so as to maintain the supply voltage output by the power conversion circuit at a stable voltage, or the switching device is controlled under the action of the constant current reference signal so as to maintain the supply current output by the power conversion circuit at a stable current, or the switching device is controlled under the action of the constant power reference signal so as to maintain the supply power output by the power conversion circuit at a vicinity of a stable power. Note that, in some embodiments, the mode selection unit 42 may not receive the constant current reference signal cc_com, and at this time, the mode selection unit 42 may not output the constant current reference signal cc_com.

Referring to fig. 7, a circuit block diagram of a constant power reference generating unit according to an embodiment of the present application is shown, and the constant power reference generating unit 41 includes a constant power reference modulating circuit 60 and a constant power reference generating circuit 411. The constant power reference modulation circuit 60 is connected to the first sampling terminal p_41 to receive the first sampling signal, and is configured to convert the first sampling signal into a constant power reference signal and output the constant power reference signal through the output terminal p_61 thereof. The constant power reference generation circuit 411 is connected to the second sampling terminal p_42 and the output terminal p_61 of the constant power reference modulation circuit 60 to receive the second sampling signal and the constant power reference signal and generate a constant power reference signal, and outputs the constant power reference signal to the post-stage circuit through the output terminal p_45. It should be noted that, in practical applications, the constant power reference generating circuit 411 may include an integrating circuit, and the first sampling signal and the constant power reference signal are integrated by the integrating circuit to generate the constant power reference signal.

The constant power reference modulation circuit 60 includes a reference modulation unit coupled to the first sampling terminal to obtain a first sampled signal and convert it to a constant power reference signal. Wherein, since the first sampling signal can reflect the load voltage, the constant power reference signal converted by the reference modulation unit in the application reflects the load current which is required to achieve the output constant power under the current load voltage. That is, the constant power reference signal may change inversely with the change of the first sampling signal, for example, when the load voltage increases, the first sampling signal may also increase, and the constant power reference signal generated by the reference modulation unit may decrease, so that the control device adjusts the load current based on the constant power reference signal to achieve constant power output of the power supply device when the load voltage changes.

In some embodiments, if the first sampling signal changes, the product of the constant power reference signal generated by the reference modulation unit and the corresponding first sampling signal is constant, and the product is a fixed value (the fixed value corresponds to a preset expected constant power value, which will not be described in detail later). Referring to fig. 8, an input-output relationship diagram of a reference modulation unit according to an embodiment of the present application is shown, wherein an abscissa Vdet is denoted as a first sampling signal, an ordinate cp_ref is denoted as a constant power reference signal, when the load voltage increases, the first sampling signal Vdet increases, the constant power reference signal cp_ref generated by the reference modulation unit decreases, and a product of an abscissa corresponding to each point on the graph shown in fig. 8 is a fixed value, so that the control device adjusts the load current based on the currently generated constant power reference signal to maintain the power supply power output by the power supply device at a stable power.

In other embodiments, if the first sampling signal changes, the constant power reference signal converted by the reference modulation unit changes inversely with the change of the first sampling signal, and under some discrete signal values of the preset first sampling signal, the product of the corresponding constant power reference signal and the first sampling signal is unchanged, that is, a fixed value (also called a stable value, which reflects the constant power expected to be reached in the preset, and will not be described in detail later). That is, the constant power reference signal and the first sampling signal have opposite multi-segment change relation, and the product of the constant power reference signal and the first sampling signal corresponding to each segment end point is a fixed value. Referring to fig. 9, which is a schematic diagram illustrating an input-output relationship of a reference modulation unit according to another embodiment of the present application, in fig. 9, a constant power reference signal and a first sampling signal are taken as an example of an opposite multi-segment linear relationship, an abscissa Vdet is denoted as a first sampling signal, an ordinate cp_ref is denoted as a constant power reference signal, when the load voltage increases, the first sampling signal Vdet also increases, the constant power reference signal cp_ref generated by the reference modulation unit decreases, unlike fig. 8, a product of an abscissa corresponding to only each line segment end point on the image shown in fig. 9 is a fixed value, such as a point a, a point B, and a point C, so that the control device adjusts the load current based on the currently generated constant power reference signal to achieve that the power supply power output by the power supply device maintains at a stable power.

It should be noted that, due to the influence of the adjustment accuracy of the control device and the modulation accuracy of the reference modulation unit, the power supply output by the power supply device is maintained at a stable power, which does not indicate that the power supply output by the power supply device is not changed at all, but means that the power supply output by the power supply device is allowed to float around a stable power, but the general trend is to be maintained at a stable power. For example, the reference modulation unit can make the constant power reference signal and the first sampling signal present a curve as shown in fig. 8, and since the product of the constant power reference signal and the first sampling signal corresponding to any point in fig. 8 is a fixed value, the control device adjusts the load current based on the constant power reference signal, so that the power supply power output by the power supply device is stable, and even if the power supply device has a deviation, the deviation is mainly influenced by the adjustment precision of the control device, and the deviation is very small or even none. For another example, the reference modulation unit can make the constant power reference signal and the first sampling signal present a curve as shown in fig. 9, because in fig. 9 only the product of the constant power reference signal and the first sampling signal corresponding to each line segment end point is a fixed value, when the constant power reference signal is present, the control device adjusts the load current based on the constant power reference signal in the linear region of the line segment, so that the power supply output by the power supply device is slightly higher than the power supply (i.e. the stable power) obtained based on the constant power signal of the line segment end point, and at this time, the deviation of the power supply output by the power supply device relative to the stable power is mainly influenced by the design principle of the reference modulation unit itself, and the more the segmented line segments in the image shown in fig. 9 will be smaller. However, since the deviation of the constant power reference signal shown in fig. 8 and 9 can be designed to be within the allowable range, the minute change of the output power in the constant power stage is regarded as maintaining the constant power unless otherwise specified in the present application.

Referring to fig. 10, a circuit block diagram of a reference modulation unit according to an embodiment of the present application is shown, and the reference modulation unit 61 includes a signal adjusting circuit 62 and a constant power reference generating circuit 63. The output end of the constant power reference generating circuit 63 is the output end p_61 of the constant power reference modulating circuit, and is used for outputting a constant power reference signal based on a reference signal output by a reference power supply, and the signal adjusting circuit 62 is coupled to the first sampling end p_41 and is connected to the constant power reference generating circuit 63, and is used for adjusting the circuit characteristics of the constant power reference generating circuit 63 according to the variation of the first sampling signal, so that the output constant power reference signal varies inversely with the variation of the first sampling signal.

The constant power reference generating circuit receives the reference signal output by the reference power supply and converts the reference signal into a constant power reference signal according to the circuit characteristic regulated by the signal regulating circuit to output. The circuit characteristics may be, for example, current, voltage, impedance, etc. of the constant power reference generating circuit. The reference power source may be a power supply of the control device, for example, the reference signal output by the control device may be a voltage signal output by the power supply after the voltage is divided by the voltage dividing circuit, or may be an electrical signal directly output by the power supply, but not limited to this, and in some embodiments, the reference power source may also be a constant voltage source preset in the control device, and the electrical signal output by the control device is the reference signal. In other embodiments, the reference power source may also be a ground, and the reference signal is a ground signal.

Referring to fig. 11, a schematic circuit diagram of a constant power reference generating circuit according to an embodiment of the application is shown, and the constant power generating circuit 63 includes a buffer Buf and an output resistor R7. The input end of the buffer Buf is used for receiving a reference signal Ref, the output end of the buffer Buf is connected with one end of an output resistor R7, the other end of the output resistor R7 is connected with a signal regulating circuit 62 to change the circuit characteristics of a constant power generating circuit 63 under the action of the signal regulating circuit 62, and the other end of the output resistor R7 is also used as an output end p_61 of the constant power reference modulating circuit and is used for outputting the constant power reference signal cp_ref. Specifically, in this embodiment, cp_ref=ref-r7 is I7, where I7 is a current flowing through R7, which is not shown in the figure, and the current value is adjusted by the signal adjusting circuit 62, when the first sampling signal received by the signal adjusting circuit 62 changes, I7 also changes accordingly, so that the constant power reference signal cp_ref also changes, and changes inversely to I7, i.e. it can be realized that the constant power reference signal changes inversely with the change of the first sampling signal. It should be noted that the buffer Buf in the embodiment shown in fig. 11 may be omitted as appropriate, and is not a necessary component.

Referring to fig. 12, a schematic circuit diagram of a constant power reference generating circuit according to another embodiment of the application is shown, and the constant power generating circuit 63 includes an output resistor R8 as shown. One end of the output resistor R8 receives the reference signal Gnd, the other end of the output resistor R8 is connected with the signal regulating circuit 62 to change the circuit characteristics of the constant power generating circuit 63 under the action of the signal regulating circuit 62, and the other end of the output resistor R8 is also used as an output end P_61 of the constant power reference modulating circuit and is used for outputting the constant power reference signal Cp_ref. Specifically, in this embodiment, cp_ref=vcc-r8×i8, where I8 is the current flowing through R8, vcc is the total power supply of the lines where the signal conditioning circuit 62 and the constant power generation circuit 63 are located, not shown in the drawing, I8 is adjusted by the signal conditioning circuit 62, when the first sampling signal received by the signal conditioning circuit 62 changes, I8 also changes accordingly, so that the constant power reference signal cp_ref also changes, and changes opposite to I8, i.e. it can be realized that the constant power reference signal changes inversely with the change of the first sampling signal.

As shown in fig. 11 and 12, the signal conditioning circuit 62 is connected to the constant power reference generating circuit 63 to adjust the current characteristic in the constant power reference generating circuit 63, specifically, the signal conditioning circuit 62 causes the current characteristic of the constant power reference generating circuit 63 to change inversely to the first sampling signal by outputting a current that changes inversely to the first sampling signal based on the first sampling signal received by the first sampling terminal p_41, which current enters the constant power reference generating circuit 63. In the case where the constant power reference generating circuit 63 is configured in another manner, the signal adjusting circuit 62 is adapted to change the voltage or impedance characteristics of the constant power reference generating circuit 63, so long as the constant power reference signal output by the constant power reference generating circuit 63 can be inversely changed according to the change of the first sampling signal.

In some embodiments, the curve of the reference modulation unit converting the first sampled signal to a constant power reference signal may be as shown in fig. 8. In view of this, in some embodiments, the curve of the current characteristic (i.e. I7 in fig. 11 and I8 in fig. 12) in the constant power reference generating circuit 63 adjusted by the signal adjusting circuit 62 based on the first sampling signal may be similar to that in fig. 8, that is, on the input-output relationship diagram corresponding to the signal adjusting circuit 62, as the first sampling signal increases, the current signal in the constant power reference generating circuit 63 adjusted by the signal adjusting circuit 62 decreases, and the product of the first sampling signal corresponding to each point on the input-output relationship curve and the current signal in the constant power reference generating circuit 63 is a fixed value, so that the reference modulating unit can implement the input-output relationship diagram shown in fig. 8.

In other embodiments, the curve of the reference modulation unit converting the first sampled signal to a constant power reference signal may be as shown in fig. 9. In view of this, in other embodiments, the input-output relationship of the signal conditioning circuit 62 for adjusting the current characteristic (i.e. I7 in fig. 11 and I8 in fig. 12) in the constant power reference generating circuit 63 based on the first sampling signal may be similar to that of fig. 9, that is, in the input-output relationship corresponding to the signal conditioning circuit 62, as the first sampling signal increases, the current signal in the constant power reference generating circuit 63 adjusted by the signal conditioning circuit 62 may decrease linearly in multiple steps, and the product of the first sampling signal corresponding to the end point of each line segment in the input-output relationship and the current signal in the constant power reference generating circuit 63 is a certain value, so that the reference modulating unit may implement the input-output relationship diagram shown in fig. 9.

Specifically, in other embodiments as described above, the signal conditioning circuit 62 receives at least one threshold signal and adjusts the current characteristics of the constant power reference circuit by signal variation from the threshold signal based on the first sampled signal. The threshold signals respectively correspond to the first sampling signals corresponding to the end points of the line segments in the input-output relationship of the signal conditioning circuit 62, which may be preset by a person skilled in the art according to actual needs, or may be randomly selected and determined within an allowable range of the first sampling signals, which is not limited herein. In the example of receiving one threshold signal, the current output by the signal conditioning circuit 62 is in an inversely varying first linear relationship with the first sampled signal, in the example of receiving the first threshold signal and the second threshold signal, the current output by the signal conditioning circuit 62 is in an inversely varying first linear relationship with the first sampled signal during the first threshold signal and the second threshold signal, and in the example of receiving more than two threshold signals, the current output by the signal conditioning circuit 62 is in an inversely varying second linear relationship with the first sampled signal, ending with each threshold signal, during the time that more than two threshold signals are received.

Referring to fig. 13, a circuit block diagram of a signal conditioning circuit according to an embodiment of the present application is shown, and the signal conditioning circuit 62 includes a current branch p_63 and a current conversion circuit 621. The current branch p_63 is used to interface with the constant power reference generating circuit 63 to change the current signal of the constant power reference generating circuit by the current signal in the current branch p_63. The current conversion circuit 621 has an input terminal connected to the first sampling terminal p_41 for receiving the first sampling signal, another input terminal for receiving the threshold signal Thr, and an output terminal coupled to the current branch p_63 for adjusting the current signal in the current branch p_63 based on the signal difference between the first sampling signal and the threshold signal Thr.

In another embodiment, the signal conditioning circuit includes a current branch, at least two current conversion circuits, and at least one current limiting circuit. The following describes a circuit configuration and an operation principle of a signal conditioning circuit including a plurality of current converting circuits and a current limiting circuit, taking two current converting circuits and one current limiting circuit as an example. Referring to fig. 14, a circuit block diagram of a signal conditioning circuit according to another embodiment of the present application is shown, and the signal conditioning circuit 62 includes a current branch p_63, a first current conversion circuit 621a, a second current conversion circuit 621b, and a first current limiting circuit 622a. The first current limiting circuit 622a is coupled between an input terminal of the first current converting circuit 621a and the first sampling terminal p_41. The other input terminal of the first current conversion circuit 621a receives the first threshold signal Thr1, and the output terminal thereof is coupled to the current branch p_63. The second current conversion circuit 621b has an input coupled to the first sampling terminal p_41 for receiving the first sampling signal, another input for receiving the second threshold signal Thr2, and an output coupled to the current branch p_63. The first current conversion circuit 621a is configured to adjust the current signal in the current branch p_63 based on a signal difference between the first sampling signal and the first threshold signal Thr1 during a period when the first sampling signal is in the first threshold signal Thr1 and the second threshold signal Thr 2. The second current conversion circuit 621b is configured to adjust the current signal in the current branch p_63 based on a signal difference between the first sampling signal and the second threshold signal Thr2 after the first sampling signal reaches the second threshold signal Thr 2. When the first current limiting circuit 622a is configured to determine that the first sampling signal reaches the second threshold signal Thr2, the current output by the output terminal of the first current converting circuit 621a is limited to a fixed current signal, so that the current signal in the current branch p_63 changes along with the current signal output by the output terminal of the second current converting circuit 621 b.

The first current limiting circuit 622a includes a first selection circuit (not shown), one input terminal of which is connected to the first sampling terminal p_41 to receive the first sampling signal, the other input terminal of which receives the second threshold signal Thr2, and an output terminal of which is coupled to the first current converting circuit 621a for outputting the first sampling signal or the second threshold signal Thr2. In an embodiment, the first selecting circuit is, for example, a small circuit, so that before the first sampling signal reaches the second threshold signal Thr2, the small circuit outputs the first sampling signal to the first current converting circuit 621a, and after the first sampling signal reaches the second threshold signal Thr2, the small circuit outputs the second threshold signal Thr2 to the first current converting circuit 621a, so that the first current converting circuit 621a outputs the fixed current signal based on a signal difference between the second threshold signal Thr2 and the first threshold signal Thr2.

Each current conversion circuit comprises a voltage-current converter, the positive input end of the voltage-current converter is connected with the output end of the first selection circuit, the negative input end of the voltage-current converter receives a corresponding threshold signal, and the output end of the voltage-current converter is connected with the current branch P_63. The voltage-to-current converter is capable of outputting a current signal in a linear relationship with a difference between a signal received at the forward input and a signal received at the reverse input based on the difference between the signals during a period in which the signal at the forward input is greater than the signal at the reverse input. In view of the fact that the threshold signal is a constant signal, that is, the current signal output by the voltage-to-current conversion circuit has an inversely varying linear relationship with the first sampling signal. Wherein each voltage-to-current conversion circuit is configured with current signals having different linear relationships based on the difference between the signals at the two input terminals. In an embodiment, the voltage-current converter may be implemented by an operational amplifier, and by configuring peripheral resistors with different magnitudes for the operational amplifier so that the peripheral resistors can have current signals with different linear relationships based on the difference between signals at two input ends, the voltage-current converter may also be implemented by a voltage-current converter implemented by the operational amplifier and a transistor, which is not limited by the application, as long as the circuit structure capable of implementing the functions described above is within the scope of the protection of the application.

Referring to fig. 15, an input-output relationship diagram of a signal conditioning circuit according to another embodiment of the present application is shown, wherein an abscissa thereof represents a first sampling signal Vdet, and an ordinate thereof represents a current I in a current branch p_63, wherein a first threshold signal Thr1 and a second threshold signal Thr2 respectively correspond to the first sampling signals Vdet1 and Vdet2 corresponding to a point D and a point F.

The operation of the signal conditioning circuit 62 described in connection with fig. 15 and the embodiments of fig. 14 is described below, in which the first current limiting circuit 622a receives the first sampling signal through the first sampling terminal p_41 during the period when the first sampling signal is smaller than the second threshold signal Thr2, and the scaling circuit outputs the first sampling signal to the first current converting circuit 621a when determining that the first sampling signal is smaller than the second threshold signal Thr2, and the current signal output by the voltage-to-current converter in the first current converting circuit 621a is in a first linear relationship with the first sampling signal which varies inversely. At this time, since the first sampling signal received at the positive input terminal of the voltage-to-current converter in the second current conversion circuit 621b is smaller than the second threshold signal Thr2 received at the negative input terminal, the second current conversion circuit 621b is in the inactive state and does not output a current signal, and the current in the current branch p_63 is determined only by the current signal output by the first current conversion circuit 621a, that is, the current in the current branch p_63 has a first linear relationship (as a line segment between D-F in fig. 15) with an inverse variation relationship with the first sampling signal. During the period when the first sampling signal is greater than the second threshold signal Thr2, the first current limiting circuit 622a receives the first sampling signal through the first sampling terminal p_41, wherein the small-taking circuit outputs the second threshold signal Thr2 to the first current converting circuit 621a when judging that the first sampling signal is greater than the second threshold signal Thr2, and the current signal output by the voltage-current converter in the first current converting circuit 621a is a fixed current signal. At this time, since the first sampling signal received at the forward input terminal of the voltage-to-current converter in the second current conversion circuit 621b is greater than the second threshold signal Thr2 received at the reverse input terminal, the voltage-to-current converter in the second current conversion circuit 621b can output the current signal in the first linear relationship that varies inversely with the first sampling signal. That is, the fixed current signal output by the first current conversion circuit 621a and the current signal output by the second current conversion circuit 621b are combined into the current signal in the current branch, but the change of the current in the current branch p_63 is only determined by the current signal output by the second current conversion circuit 621b, that is, the current in the current branch p_63 has a second linear relationship (a line segment following F in fig. 15) with the opposite change relationship with the first sampling signal.

It should be noted that, in fig. 14 and fig. 15, only one example is shown, and the number of current converting circuits in the signal conditioning circuit is not limited to two, and only one current limiting circuit is shown in the embodiment, the current converting circuit and the current limiting circuit may be further added in the connection manner shown in fig. 14, for example, the information conditioning circuit further includes a third current converting circuit having an input terminal connected to the first sampling terminal p_41 and a second current limiting circuit having another input terminal receiving the third threshold signal, the second current limiting circuit being connected between the first sampling terminal p_41 and the second current converting circuit 621a, and so on. The working principle is also similar to that of fig. 14, and is not described here again.

It should be noted that, in the above-mentioned embodiments, the reference modulation unit converts the first sampling signal reflecting the load change into the constant-power reference signal, and according to the embodiment shown in fig. 5, the power conversion circuit only releases energy to the load side and the third sampling circuit to supply power to the load side when the switching device is turned off, that is, the signal output by the third sampling circuit is not able to reflect the load voltage during the energy storage phase (or called the excitation phase) of the power conversion circuit, and only the third sampling signal output by the third sampling circuit is able to reflect the load voltage during the energy release phase (or called the demagnetization phase) of the power conversion circuit.

In view of this, in some embodiments, referring to fig. 16, a circuit block diagram of a constant power reference modulation circuit according to an embodiment of the present application is shown, where the constant power reference modulation circuit 60 includes a demagnetizing sampling unit 64 in addition to the reference modulation unit 61 according to any of the foregoing embodiments. The demagnetizing and sampling unit 64 is coupled between the first sampling end p_41 and the reference modulating unit 61, and is configured to output the first sampling signal to the reference modulating unit 61 through the output end p_62 when the power conversion circuit is detected to be in a demagnetizing stage, so that the reference modulating unit 61 processes the first sampling signal according to the circuit architecture and principles of the above embodiments.

Referring to fig. 17, a schematic circuit diagram of a demagnetization sampling unit according to an embodiment of the present application is shown, and as shown in the drawing, the demagnetization sampling unit 64 includes a demagnetization detection circuit 641 and a demagnetization sampling circuit 642. The demagnetization detecting circuit 641 is coupled to the first sampling end p_41 for detecting the first sampling signal to output a demagnetization detecting signal when the power conversion circuit is in a demagnetization stage. The demagnetizing sampling circuit 642 has one end coupled to the first sampling end p_41 and the other end coupled to the demagnetizing detecting circuit 641, and is configured to output the first sampling signal by conducting a line between the first sampling end p_41 and the output end p_62 of the demagnetizing sampling unit 64 when receiving the demagnetizing detecting signal. In an embodiment, the demagnetization detecting circuit 641 may include a comparing circuit for comparing the first sampling signal with a preset threshold value to determine whether the first sampling signal at this time can reflect the load voltage, that is, whether the power conversion circuit is in the demagnetization stage. The demagnetization sampling circuit 642 may include a switch S1 and a resistor R9 as shown in fig. 17, where the switch S1 and the resistor R9 are connected in series between the first sampling terminal p_41 and the output terminal p_62 of the demagnetization sampling unit 64, and the switch S1 may be controlled by the demagnetization detection signal to be turned on, so as to output the first sampling signal from the output terminal p_62.

As shown in fig. 6, the constant power reference generating unit 41 in the control device 40 outputs a constant power reference signal to the mode selecting unit 42 using the circuit configuration and the operation principle shown in the embodiments shown in fig. 7 to 17 and described therein. The function of the mode selection unit 42 and the connection manner in the control device 40 are described with reference to fig. 6, and will not be described again.

Referring to fig. 18, a circuit block diagram of a mode selection unit according to an embodiment of the present application is shown, and the mode selection unit 42 includes a comparison circuit 421 and a selection circuit 422. The comparing circuit 421 is coupled to the third sampling end p_43 and connected to the output end p_45 of the constant power reference signal generating unit, and is configured to output a high level signal when the third sampling signal output by the third sampling end p_43 is less than the first load threshold load1, so that the constant power reference signal output by the output end p_45 is forced to be the high level signal. The selection circuit 422 is coupled to the third sampling terminal p_43 to receive a third sampling small signal, and is connected to the output terminal p_45 of the constant power reference signal generating unit to receive a constant power reference signal, and the selection circuit 422 further receives a constant current reference signal cc_com for selectively outputting the constant power reference signal, or outputting the constant current reference signal cc_com, or outputting the third sampling signal as a constant voltage reference signal based on a magnitude relation of the received signal.

The comparison circuit 421 includes a comparator 4211 and a switching tube 4212. The positive input end of the comparator 4211 is connected to the third sampling end p_43 to receive the third sampling signal, the negative input end receives the first load threshold load1, the output end is connected to the control end of the switching tube 4212, the first end of the switching tube 4212 is connected to a power supply Vcc, and the second end is connected to the output end p_45. The comparator 4211 outputs a low level signal when the third sampling signal is smaller than the first load threshold load1, and the switching tube 4212 is, for example, a P-type transistor, and is turned on when the control terminal thereof receives the low level signal, so that the control terminal p_45 of the power supply input output terminal of the power supply Vcc is forced to be a high level signal by the constant power reference signal. It should be noted that the selection and connection modes of the comparator 4211 and the switching tube 4212 can be adaptively adjusted, and the application is not limited thereto.

As can be seen from the description of fig. 4, the power supply device outputs different power supplies under different load capacities, specifically, outputs constant voltage power supply to the load during the period when the load current is smaller than the first preset current, outputs constant power supply to the load during the period when the load current is larger than the first preset current and smaller than the second preset current, and outputs constant current power supply to the load during the period when the load current reaches the second preset current. In view of this, the first load threshold load1 described in fig. 18 corresponds to a first preset current, the constant current reference signal cc_com corresponds to a second preset current, and the selection circuit 422 includes a decimating circuit, and the decimating circuit selects the smallest one of the received constant power reference signal, the third sampling signal, and the constant current reference signal to output. Specifically, the third sampling signal reflects the load current, and during the period when the load current is smaller than the first preset current, the third sampling signal is smaller than both the constant current reference signal cc_com and the first load threshold load1, so that the comparison circuit 421 is conducted to enable the power supply of the power supply source Vcc to be poured into the output terminal p_45, and thus the signal of the output terminal p_45 flowing into the small circuit is maximized, and further, the small circuit selects the third sampling signal as the constant voltage power supply reference signal to be outputted to the rear-stage circuit, so that the power supply device can output constant voltage power supply to the load during the period when the load current is smaller than the first preset current. As the load current increases to the maximum current that can be provided by the constant voltage power supply, that is, to a period that exceeds the first preset current but reaches the second preset current, the third sampling signal is smaller than the constant current reference signal cc_com and larger than the first load threshold load1, so that the comparison circuit 421 is disconnected to enable the output terminal p_45 to output as the constant power reference signal to flow into the small taking circuit, and the small taking circuit selects the constant power reference signal to output to the rear-stage circuit, so that the power supply device can output constant power to the load during the period that the load current is larger than the first preset current and smaller than the second preset current. When the load current continues to be increased to the maximum output current, namely to the second preset current, at this time, the load voltage is very low, so that the constant power reference signal output by the output end p_45 reaches the maximum, and the constant current reference signal cc_com is selected by the small circuit and output to the later-stage circuit, so that the power supply device can realize constant current power supply output to the load during the period that the load current reaches the second preset current.

It should be noted that fig. 18 is only an example of a mode selection unit, in practical application, the mode selection unit 42 may omit the comparison circuit 421 based on the circuit structure shown in fig. 18, and the selection circuit 422 may receive the third sampling signal, the constant power reference signal, and the constant current reference signal cc_com, and may selectively output the constant power reference signal, the constant current reference signal cc_com, or the third sampling signal as the constant voltage reference signal based on the magnitude relation of the received signals. The selection circuit 422 includes a decimating circuit, and the decimating circuit selects the smallest of the received constant power reference signal, the third sampling signal, and the constant current reference signal to output. When the load is light-load (if the load current is smaller than the first preset current), the third sampling signal reflecting the load current is minimum, and the small circuit selects the third sampling signal as a constant-voltage power supply reference signal to be output to the later-stage circuit. When the load is heavy (if the load current is larger than the first preset current), the third sampling signal is increased, the constant power reference signal is minimum at the moment, and the constant power reference signal output by the small circuit is taken to be output to the later-stage circuit. When the load is overweight (if the load current is greater than the second preset current), the load voltage is lower at this moment, and the constant power reference signal is higher, so that when the load current is continuously increased to the maximum output current, namely to the second preset current, at this moment, the load voltage is very low, and thus the constant current reference signal cc_com is minimum, and the small circuit selects the constant current reference signal cc_com to output to the later-stage circuit.

As shown in fig. 6, the mode selection unit 42 in the control device 40 outputs signals to the switch control unit 43 using the circuit configuration and the operation principle shown in fig. 18 and the embodiments described therein. The function of the switch control unit 43 and the connection manner in the control device 40 are described with reference to fig. 6, and will not be described again.

Referring to fig. 19, a circuit block diagram of a switch control unit according to an embodiment of the application is shown, and the switch control unit 43 includes an off detection circuit 431, an on detection circuit 432, and a driving circuit 433. One input end of the off detection circuit 431 is coupled to the output end p_46 of the mode selection unit, and the other input end is coupled to the second sampling end p_42 to receive the second sampling signal, for outputting an off signal to the driving circuit 433 when the second sampling signal reaches one of the reference signals outputted from the output end p_46 of the mode selection unit. The conduction detection circuit 432 is configured to output a conduction signal to the driving circuit 433. The input end of the driving circuit 433 is connected to the turn-off detection circuit 431 and the turn-on detection circuit 432, and the output end is the output end p_44 of the control device, which is used for being connected to a switching device (such as the switching device 30 in fig. 4), and the driving circuit 433 outputs a driving signal based on the turn-on signal and the turn-off signal to control the turn-on or turn-off of the switching device. The off detection circuit 431 includes a comparator (not shown), wherein a positive input terminal of the comparator is connected to the second sampling terminal p_43, and a negative input terminal of the comparator is connected to the output terminal p_46 of the mode selection unit, and the function is achieved by comparing the second sampling signal with a reference signal output from the output terminal p_46. The conduction detection circuit 432 may be, for example, a PWM generation circuit, and the rising edge of the PWM pulse signal outputted by the PWM generation circuit is used as a conduction signal to the driving circuit 433, and the conduction detection circuit 432 may also have the same architecture as a conduction detection circuit in a control device that implements a switch control type in a PFM control manner, where an input terminal of the conduction detection circuit 432 needs to be coupled to at least one of the first sampling terminal, the second sampling terminal, and the third sampling terminal, so as to output the conduction signal to the driving circuit 433 based on the obtained signal. The driving circuit 433 may include, but is not limited to, a switch, a power supply, a trigger, a timer, a selector, an and gate, or the like according to the control requirement and the control logic. In addition, depending on the circuit division and design, only the off detection circuit 431 may be used as the switch control unit 43, or at least one of the on detection circuit 432 and the driving circuit 433 and the off detection circuit 431 may be used as the switch control unit 43.

The operation principle of the power supply device according to the present application will be described with reference to fig. 1 to 20. The external driving signal is rectified by the rectifying circuit and then is output to the filtering circuit, so that the filtering signal is output to the power conversion circuit, and under different load capacities, the power conversion circuit outputs different types of power supplies based on the on or off of the switching device controlled by the control device. Specifically, the sampling circuit outputs a first sampling signal reflecting the load voltage, a second sampling signal reflecting the peak current of the power conversion circuit, and a third sampling signal reflecting the load current to the control device. When the load current is smaller (for example, smaller than the first preset current), the mode selection unit in the control device selects to output a constant voltage reference signal to the switch control unit, and the switch control unit controls the turn-off time of the switching device based on the constant voltage reference signal, so that the supply voltage output by the power conversion circuit is maintained at a stable voltage (also called to output constant voltage supply). Along with the continuous increase of the load current, when the load current is increased to the first preset current but does not reach the second preset current, the mode selection unit in the control device selects to output a constant power reference signal to the switch control unit, and the switch control unit controls the turn-off time of the switching device based on the constant power reference signal, so that the power supply power output by the power conversion circuit is maintained at a stable power (also called outputting constant power supply). When the load current continues to be increased to a second preset current, the mode selection unit in the control device selects to output a constant current reference signal to the switch control unit, and the switch control unit controls the turn-off time of the switching device based on the constant current reference signal, so that the supply current output by the power conversion circuit is maintained at a stable current (also called output constant current supply), and the stable current is the second preset current.

The application also discloses a control chip, which is packaged with the constant power reference modulation circuit according to any embodiment or the control device according to any embodiment. The control chip further comprises a plurality of pins, and in one embodiment, the chip is packaged with the reference modulation unit and the demagnetizing sampling unit, wherein the plurality of pins comprise a first pin for receiving a first sampling signal reflecting load voltage, a second pin for outputting a constant power reference signal, a third pin for acquiring a power supply of the chip, and a fourth pin for grounding. In another embodiment, the chip package is provided with the constant power reference generating unit, the mode selecting unit and the switch control unit as described above, and the plurality of pins include a first pin for receiving a first sampling signal reflecting a load voltage, a second pin for receiving a second sampling signal reflecting a peak current of the power conversion circuit, a third pin for receiving a third sampling signal reflecting a load current, a fourth pin for outputting a driving signal, a fifth pin for obtaining a power supply of the chip, and a sixth pin for grounding. The modules and circuits in each embodiment refer to the foregoing descriptions of fig. 6 to 19, and are not repeated here.

The application also discloses a constant power reference modulation method which comprises the following steps of S11 and S12. Wherein the constant power reference modulation method may be performed by the aforementioned constant power reference modulation circuit, or other constant power reference modulation circuits that may perform the modulation method.

In step S11, a first sampling signal reflecting a load voltage is received.

Here, a constant power reference modulation circuit obtains a first sampling signal reflecting a load voltage by coupling with a sampling circuit. Examples of the way in which the constant power reference modulation circuit obtains the first sampling signal include obtaining the first sampling signal by using an electrical connection way, obtaining the first sampling signal by using an optocoupler way, obtaining the first sampling signal by using an inductance way, and the like.

Taking the descriptions of fig. 7 to 17 as an example, the constant power reference modulation circuit receives the first sampling signal through the first sampling end, and the specific circuit structure and the acquisition manner refer to the descriptions of fig. 5 to 17, which are not repeated herein.

In step S12, the first sampling signal is converted into a constant power reference signal, wherein the constant power reference signal varies inversely with the variation of the first sampling signal.

Wherein the constant power reference modulation circuit converts the first sampled signal to a constant power reference signal. For example, the output constant power reference signal and the first sampling signal have opposite multi-section change relations, the product of the constant power reference signal corresponding to each section end point and the first sampling signal is a fixed value, and each section change relation is a linear relation. In an embodiment, the constant power reference modulation circuit adjusts the circuit characteristics of the constant power reference modulation circuit according to the signal change of the first sampling signal relative to at least one threshold signal, so that the output constant power reference signal changes inversely with the change of the first sampling signal, and the circuit characteristics comprise electrical characteristics such as resistance, current, voltage and the like.

Taking the descriptions of fig. 7 to 17 as an example, the constant power reference modulation circuit performs step S21 by adopting the circuit structure and the working principle shown in any one of the embodiments of fig. 7 to 17 and the descriptions thereof, and the descriptions thereof with respect to fig. 7 to 17 are specifically referred to, and are not repeated herein.

The application also discloses a control method of the switching device, which comprises the steps of S21, S22, S23 and S24. Wherein the control method may be performed by the aforementioned control device, or other control circuits that may perform the control method.

In step S21, a second sampling signal reflecting the peak current of a power conversion circuit and a third sampling signal reflecting the load current are obtained. Wherein the power conversion circuit is coupled to the switching device.

The control device obtains a second sampling signal reflecting the peak current of a power conversion circuit and a third sampling signal reflecting the load current by coupling with the sampling circuit. Examples of the manner of obtaining the second sampling signal by the control device include obtaining the second sampling signal by an electrical connection manner, obtaining the second sampling signal by a resistance manner, obtaining the second sampling signal by an inductance manner, and the like. Examples of the way in which the control device obtains the third sampling signal include obtaining the third sampling signal by using an electrical connection method, obtaining the second sampling signal by using a photoelectric sensing method, obtaining the third sampling signal by using an inductance sensing method, and the like.

Taking the embodiment shown in fig. 5 and fig. 6 and the description thereof as an example, the control device obtains the second sampling signal and the third sampling signal by using the second sampling end and the third sampling end, and the specific obtaining manner is please refer to the description of fig. 5 and fig. 6, and the description thereof is omitted herein.

In step S22, the first sampled signal is converted into a constant power reference signal.

Here, the constant power reference modulation circuit in the control device adopts the disclosed constant power reference modulation method (e.g. step S11 and step S12) of the present application, and the foregoing description is specifically referred to, and will not be repeated here.

In step S23, a constant power reference signal is output based on the second sampling signal and the constant power reference signal.

Here, the control device may output a constant power reference signal based on the second sampling signal and the constant power reference signal by the constant power reference generation unit therein. In some embodiments, the constant power reference generation unit integrates the first sampled signal and a constant power reference signal to generate the constant power reference signal.

Taking the embodiment shown in fig. 7 to 17 and the description thereof as an example, the constant power reference generating unit in the control device performs step S23 by adopting the circuit structure and the working principle shown in any one of the embodiment shown in fig. 7 to 17 and the description thereof, and the description thereof with respect to fig. 7 to 17 is specifically referred to, and will not be repeated here.

In some embodiments, step S25 is further included before step S24, and in step S25, a constant current reference signal is obtained.

Here, a mode selection unit in the control device acquires the constant current reference signal. Taking the embodiments shown in fig. 6 and fig. 18 and the descriptions thereof as examples, the mode selecting unit in the control device obtains the constant current reference signal, and the circuit architecture and the process of executing step S25 are shown in each embodiment of fig. 6 and fig. 18 and the descriptions thereof, and are not repeated herein.

In step S24, the constant power reference signal, the constant current reference signal, or the third sampling signal is selectively output, or the switching device is controlled under the action of the constant voltage reference signal so that the supply voltage output by the power conversion circuit is maintained at a stable voltage, or the switching device is controlled under the action of the constant power reference signal so that the supply power output by the power conversion circuit is maintained at a stable power, and the supply current output by the power conversion circuit is maintained at a stable current under the action of the constant current reference signal.

Here, the mode selecting unit in the control device selectively outputs the constant power reference signal, or outputs the constant current reference signal, or outputs the third sampling signal as the constant voltage reference signal, according to the magnitude relation of the third sampling signal, the constant power reference signal, and the constant current reference signal. Specifically, the mode selection unit is further configured to output a high-level signal when the third sampling signal is determined to be less than the first load threshold, so that the constant-power reference signal received by the mode selection unit is forced to be the high-level signal, and the mode selection unit selects the smallest one of the received signals to output.

Taking the embodiments shown in fig. 6, 18 and 19 and the descriptions thereof as examples, the mode selecting unit and the switch controlling unit in the control device execute step S24 by adopting the circuit structure and the working principle shown in any one of the embodiments shown in fig. 6, 18 and 19 and the descriptions thereof, and the descriptions of fig. 6, 18 and 19 will be omitted herein.

In summary, the constant power reference modulation circuit, the control device, the chip, the power supply device and the method disclosed by the application can provide different power supplies according to different load capacities, so that when the load is supplied with power, the load can be quickly in a high-power supply stage, and the energy utilization rate is improved.

The above embodiments are merely illustrative of the principles of the present application and its effectiveness, and are not intended to limit the application. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the application. Accordingly, it is intended that all equivalent modifications and variations of the application be covered by the claims, which are within the ordinary skill of the art, be within the spirit and scope of the present disclosure.

Claims (22)

Translated fromChinese

1.一种恒功率基准调制电路，其特征在于，配置于一电源装置中，包括：1. A constant power reference modulation circuit, configured in a power supply device, comprising:第一采样端，用于接收反映负载电压的第一采样信号；A first sampling terminal, configured to receive a first sampling signal reflecting a load voltage;基准调制单元，耦接于所述第一采样端，用于将所述第一采样信号转换为恒功率基准信号；所述基准调制单元包括：用于基于一基准电源所输出的基准信号输出恒功率基准信号的恒功率基准产生电路以及耦接于所述第一采样端和所述恒功率基准产生电路的信号调节电路，所述信号调节电路接收至少一个阈值信号，用于根据所述第一采样信号相对于所述阈值信号的信号变化调节所述恒功率基准产生电路的电路特性，以使得所输出的恒功率基准信号随着所述第一采样信号的变化呈相反变化；在所述恒功率基准信号的作用下，所述电源装置输出的供电功率维持在一稳定功率；A reference modulation unit is coupled to the first sampling terminal and is configured to convert the first sampling signal into a constant power reference signal. The reference modulation unit includes: a constant power reference generation circuit configured to output a constant power reference signal based on a reference signal output by a reference power supply; and a signal conditioning circuit coupled to the first sampling terminal and the constant power reference generation circuit. The signal conditioning circuit receives at least one threshold signal and is configured to adjust circuit characteristics of the constant power reference generation circuit based on a signal change of the first sampling signal relative to the threshold signal, so that the output constant power reference signal changes inversely with changes in the first sampling signal. Under the action of the constant power reference signal, the power output by the power supply device is maintained at a stable power.其中，所述信号调节电路包括接入所述恒功率基准产生电路的电流支路以及至少一个电流转换电路，所述电流转换电路的一输入端接收所述第一采样信号，另一输入端接收所述阈值信号，以及输出端耦接于所述电流支路，用于基于所述第一采样信号与所述阈值信号的信号差调节所述电流支路中的电流信号，其中，不同电流转换电路所接收的阈值信号不同。In which, the signal conditioning circuit includes a current branch connected to the constant power reference generation circuit and at least one current conversion circuit, one input end of the current conversion circuit receives the first sampling signal, the other input end receives the threshold signal, and the output end is coupled to the current branch, and is used to adjust the current signal in the current branch based on the signal difference between the first sampling signal and the threshold signal, wherein the threshold signals received by different current conversion circuits are different.2.根据权利要求1所述的恒功率基准调制电路，其特征在于，所述恒功率基准信号与所述第一采样信号呈相反的多段变化关系；其中，各段端点对应的恒功率基准信号和第一采样信号的乘积为一固定值。2. The constant power reference modulation circuit according to claim 1 is characterized in that the constant power reference signal and the first sampling signal have a multi-segment change relationship that is opposite to each other; wherein the product of the constant power reference signal and the first sampling signal corresponding to each segment endpoint is a fixed value.3.根据权利要求2所述的恒功率基准调制电路，其特征在于，所述恒功率基准信号与所述第一采样信号呈相反的多段线性关系。3 . The constant power reference modulation circuit according to claim 2 , wherein the constant power reference signal and the first sampling signal have an opposite multi-segment linear relationship.4.根据权利要求1所述的恒功率基准调制电路，其特征在于，还包括：退磁采样单元，耦接于所述第一采样端和所述基准调制单元之间，用于在检测到所述电源装置中的功率转换电路处于退磁阶段时，将所述第一采样信号输出给所述基准调制单元。4. The constant power reference modulation circuit according to claim 1 is characterized in that it further includes: a demagnetization sampling unit, coupled between the first sampling end and the reference modulation unit, and configured to output the first sampling signal to the reference modulation unit when it is detected that the power conversion circuit in the power supply device is in a demagnetization stage.5.根据权利要求4所述的恒功率基准调制电路，其特征在于，所述退磁采样单元包括：5. The constant power reference modulation circuit according to claim 4, wherein the demagnetization sampling unit comprises:退磁检测电路，耦接于所述第一采样端，用于检测所述第一采样信号以在所述功率转换电路处于退磁阶段时输出退磁检测信号；a demagnetization detection circuit, coupled to the first sampling terminal, for detecting the first sampling signal and outputting a demagnetization detection signal when the power conversion circuit is in a demagnetization stage;退磁采样电路，耦接于所述退磁检测电路，用于在接收到所述退磁检测信号时将所述第一采样信号予以输出。The demagnetization sampling circuit is coupled to the demagnetization detection circuit and is configured to output the first sampling signal when receiving the demagnetization detection signal.6.根据权利要求1所述的恒功率基准调制电路，其特征在于，所述信号调节电路包括至少两个电流转换电路，所述信号调节电路还包括：6. The constant power reference modulation circuit according to claim 1, wherein the signal conditioning circuit comprises at least two current conversion circuits, and the signal conditioning circuit further comprises:至少一个电流限制电路，所述电流限制电路耦接于其中一电流转换电路，用于判断所述第一采样信号达到另一电流转换电路接收的阈值信号时，限制与之相耦接的电流转换电路所输出的电流信号为一固定电流信号，以使得所述电流支路中的电流信号随着另一电流转换电路所输出的电流信号变化。at least one current limiting circuit, the current limiting circuit being coupled to one of the current conversion circuits and configured to limit the current signal output by the coupled current conversion circuit to a fixed current signal when determining that the first sampling signal reaches a threshold signal received by the other current conversion circuit, so that the current signal in the current branch changes with the current signal output by the other current conversion circuit.7.根据权利要求6所述的恒功率基准调制电路，其特征在于，所述至少两个电流转换电路为第一电流转换电路和第二电流转换电路，所述电流限制电路包括：7. The constant power reference modulation circuit according to claim 6, wherein the at least two current conversion circuits are a first current conversion circuit and a second current conversion circuit, and the current limiting circuit comprises:第一选择电路，其一输入端接收所述第一采样信号，另一输入端接收第二阈值信号，以及输出端耦接于第一电流转换电路，用于输出所述第一采样信号或第二阈值信号；a first selection circuit having one input terminal receiving the first sampling signal, another input terminal receiving the second threshold signal, and an output terminal coupled to the first current conversion circuit for outputting the first sampling signal or the second threshold signal;其中，所述第一电流转换电路基于所述第二阈值信号与第一阈值信号的信号差输出所述固定电流信号，所述固定电流信号与所述第二电流转换电路基于所述第一采样信号与第二阈值信号的信号差所输出的电流信号合并为所述电流支路中的电流信号；The first current conversion circuit outputs the fixed current signal based on the signal difference between the second threshold signal and the first threshold signal, and the fixed current signal and the current signal output by the second current conversion circuit based on the signal difference between the first sampling signal and the second threshold signal are combined into the current signal in the current branch;其中，第一阈值信号对应为第一电流转换电路所接收的阈值信号，第二阈值信号对应为第二电流转换电路所接收的阈值信号。The first threshold signal corresponds to the threshold signal received by the first current conversion circuit, and the second threshold signal corresponds to the threshold signal received by the second current conversion circuit.8.根据权利要求1所述的恒功率基准调制电路，其特征在于，所述恒功率基准产生电路包括输出电阻，所述输出电阻的一端用于获取所述基准信号，另一端与所述信号调节电路相耦接，用于输出所述恒功率基准信号。8. The constant power reference modulation circuit according to claim 1 is characterized in that the constant power reference generation circuit includes an output resistor, one end of the output resistor is used to obtain the reference signal, and the other end is coupled to the signal conditioning circuit for outputting the constant power reference signal.9.一种开关器件的控制装置，其特征在于，所述控制装置包括：9. A control device for a switching device, characterized in that the control device comprises:第二采样端，用于获取反映一功率转换电路的峰值电流的第二采样信号；其中，所述功率转换电路与所述开关器件相耦接；a second sampling terminal for acquiring a second sampling signal reflecting a peak current of a power conversion circuit coupled to the switching device;第三采样端，用于获取反映负载电流的第三采样信号；A third sampling terminal is used to obtain a third sampling signal reflecting the load current;恒功率参考信号生成单元，耦接于所述第二采样端，其包括如权利要求1至8任一所述的恒功率基准调制电路，用于基于所述第二采样信号和所述恒功率基准信号输出恒功率参考信号；a constant power reference signal generating unit, coupled to the second sampling end, comprising the constant power reference modulation circuit according to any one of claims 1 to 8, configured to output a constant power reference signal based on the second sampling signal and the constant power reference signal;模式选择单元，耦接于所述第三采样端和所述恒功率参考生成单元，用于选择性的输出所述恒功率参考信号或输出所述第三采样信号作为恒压参考信号；a mode selection unit, coupled to the third sampling terminal and the constant power reference generation unit, configured to selectively output the constant power reference signal or output the third sampling signal as a constant voltage reference signal;开关控制单元，耦接于所述模式选择单元，用于在所述恒压参考信号的作用下控制所述开关器件以使得所述功率转换电路输出的供电电压维持在一稳定电压，或者在恒功率参考信号的作用下控制所述开关器件以使得所述功率转换电路输出的供电功率维持在一稳定功率。A switch control unit, coupled to the mode selection unit, is configured to control the switch device under the action of the constant voltage reference signal so that the supply voltage output by the power conversion circuit is maintained at a stable voltage, or to control the switch device under the action of the constant power reference signal so that the supply power output by the power conversion circuit is maintained at a stable power.10.根据权利要求9所述的开关器件的控制装置，其特征在于，所述恒功率基准信号与所述第一采样信号呈相反的多段变化关系，各段端点对应于所述功率转换电路输出的供电功率维持为所述稳定功率。10. The control device of the switching device according to claim 9, characterized in that the constant power reference signal and the first sampling signal have a multi-segment change relationship that is opposite to each other, and the power supply power output by the power conversion circuit corresponding to each segment endpoint is maintained at the stable power.11.根据权利要求9所述的开关器件的控制装置，其特征在于，所述模式选择单元包括：11. The control device for a switching device according to claim 9, wherein the mode selection unit comprises:比较电路，耦接于所述第三采样端和所述恒功率参考信号生成单元，用于判断所述第三采样信号小于第一负载阈值时输出高准位信号以使得所述恒功率参考信号被强制为所述高准位信号；a comparison circuit, coupled to the third sampling terminal and the constant power reference signal generation unit, configured to output a high-level signal when determining that the third sampling signal is less than a first load threshold, so that the constant power reference signal is forced to be the high-level signal;选择电路，耦接于所述第三采样端和所述恒功率参考信号生成单元，用于基于所接收信号的大小关系选择性的输出所述恒功率参考信号或输出所述第三采样信号作为恒压参考信号。The selection circuit is coupled to the third sampling terminal and the constant power reference signal generation unit, and is configured to selectively output the constant power reference signal or the third sampling signal as a constant voltage reference signal based on the magnitude relationship of the received signal.12.根据权利要求9所述的开关器件的控制装置，其特征在于，所述模式选择单元还接收一恒流参考信号，用于选择性的输出所述恒流参考信号，在所述恒流参考信号的作用下，所述功率转换电路输出的供电电流维持在一稳定电流。12. The control device of the switching device according to claim 9 is characterized in that the mode selection unit also receives a constant current reference signal and is used to selectively output the constant current reference signal, and under the action of the constant current reference signal, the power supply current output by the power conversion circuit is maintained at a stable current.13.根据权利要求9所述的开关器件的控制装置，其特征在于，所述开关控制单元包括：13. The control device for a switching device according to claim 9, wherein the switch control unit comprises:关断检测电路，耦接于所述模式选择单元和所述第二采样端，用于判断所述第二采样信号达到所述模式选择单元所输出的其中一种参考信号时输出关断信号，以使所述开关器件关断。The turn-off detection circuit is coupled to the mode selection unit and the second sampling terminal, and is used to output a turn-off signal when determining that the second sampling signal reaches one of the reference signals output by the mode selection unit to turn off the switch device.14.根据权利要求13所述的开关器件的控制装置，其特征在于，所述开关控制单元还包括：导通检测电路，用于输出导通信号以使所述开关器件导通。14 . The control device for a switching device according to claim 13 , wherein the switch control unit further comprises: a conduction detection circuit configured to output a conduction signal to turn on the switching device.15.根据权利要求14所述的开关器件的控制装置，其特征在于，所述开关控制单元还包括：驱动电路，耦接于所述导通检测电路和所述关断检测电路，用于基于所述导通信号和所述关断信号输出驱动信号以控制所述开关器件的导通或关断。15. The control device of the switching device according to claim 14 is characterized in that the switching control unit further includes: a driving circuit, coupled to the conduction detection circuit and the turn-off detection circuit, for outputting a driving signal based on the conduction signal and the turn-off signal to control the conduction or turn-off of the switching device.16.一种电源装置，其特征在于，包括：16. A power supply device, comprising:整流电路，用于接收外部驱动信号以输出整流信号；a rectifier circuit, configured to receive an external drive signal and output a rectified signal;滤波电路，耦接于所述整流电路，用于滤波所述整流信号以输出滤波信号；a filter circuit, coupled to the rectifier circuit, for filtering the rectified signal to output a filtered signal;如权利要求9至15任一所述的控制装置，用于基于第一采样信号、第二采样信号、以及第三采样信号输出驱动信号；The control device according to any one of claims 9 to 15, configured to output a drive signal based on the first sampling signal, the second sampling signal, and the third sampling signal;开关器件，其控制端耦接于所述控制装置，用于基于所述驱动信号导通或关断；a switch device, a control terminal of which is coupled to the control device and configured to be turned on or off based on the drive signal;功率转换电路，耦接于所述开关器件和所述滤波电路，用于基于所述开关器件的导通或关断对所述滤波信号进行能量转换以向负载输出恒压供电或恒功率供电；a power conversion circuit, coupled to the switching device and the filtering circuit, for performing energy conversion on the filtered signal based on the on/off state of the switching device to output constant voltage power supply or constant power power supply to a load;采样电路，耦接于所述控制装置和所述功率转换电路，用于分别采样反映负载电压、负载电流、以及功率转换电路的峰值电流的电信号以对应输出所述第一采样信号、第三采样信号、和第二采样信号。The sampling circuit is coupled to the control device and the power conversion circuit, and is used to respectively sample electrical signals reflecting the load voltage, the load current, and the peak current of the power conversion circuit to correspondingly output the first sampling signal, the third sampling signal, and the second sampling signal.17.一种恒功率基准调制方法，其特征在于，适用于如权利要求1至8任一所述的恒功率基准调制电路，包括以下步骤：17. A constant power reference modulation method, characterized in that it is applicable to the constant power reference modulation circuit according to any one of claims 1 to 8, comprising the following steps:接收反映负载电压的第一采样信号；receiving a first sampling signal reflecting a load voltage;将所述第一采样信号转换为恒功率基准信号；其中，所述恒功率基准信号随着所述第一采样信号的变化呈相反变化。The first sampling signal is converted into a constant power reference signal; wherein the constant power reference signal changes inversely with changes in the first sampling signal.18.根据权利要求17所述的恒功率基准调制方法，其特征在于，所述恒功率基准信号与所述第一采样信号呈相反的多段变化关系；其中，各段端点对应的恒功率基准信号和第一采样信号的乘积为一固定值。18. The constant power reference modulation method according to claim 17 is characterized in that the constant power reference signal and the first sampling signal have a multi-segment change relationship that is opposite to each other; wherein the product of the constant power reference signal and the first sampling signal corresponding to each segment endpoint is a fixed value.19.根据权利要求18所述的恒功率基准调制方法，其特征在于，所述恒功率基准信号与所述第一采样信号呈相反的多段线性关系。19 . The constant power reference modulation method according to claim 18 , wherein the constant power reference signal and the first sampling signal are in an opposite multi-segment linear relationship.20.一种开关器件的控制方法，其特征在于，包括以下步骤：20. A method for controlling a switching device, comprising the following steps:获取反映一功率转换电路的峰值电流的第二采样信号和反映负载电流的第三采样信号；其中，所述功率转换电路与所述开关器件相耦接；Acquiring a second sampling signal reflecting a peak current of a power conversion circuit and a third sampling signal reflecting a load current; wherein the power conversion circuit is coupled to the switching device;采用如权利要求17至19任一所述的恒功率基准调制方法将第一采样信号转换为所述恒功率基准信号；Converting the first sampling signal into the constant power reference signal using the constant power reference modulation method according to any one of claims 17 to 19;基于所述第二采样信号和所述恒功率基准信号输出恒功率参考信号；outputting a constant power reference signal based on the second sampling signal and the constant power reference signal;选择性的输出所述恒功率参考信号或输出所述第三采样信号作为恒压参考信号；selectively outputting the constant power reference signal or outputting the third sampling signal as a constant voltage reference signal;在所述恒压参考信号的作用下控制所述开关器件以使得所述功率转换电路输出的供电电压维持在一稳定电压，或者在恒功率参考信号的作用下控制所述开关器件以使得所述功率转换电路输出的供电功率维持在一稳定功率。Under the action of the constant voltage reference signal, the switching device is controlled so that the power supply voltage output by the power conversion circuit is maintained at a stable voltage, or under the action of the constant power reference signal, the switching device is controlled so that the power supply power output by the power conversion circuit is maintained at a stable power.21.根据权利要求20所述的开关器件的控制方法，其特征在于，还包括以下步骤：21. The method for controlling a switching device according to claim 20, further comprising the following steps:获取一恒流参考信号；Obtaining a constant current reference signal;选择性的输出所述恒流参考信号，在所述恒流参考信号的作用下，所述功率转换电路输出的供电电流维持在一稳定电流。The constant current reference signal is selectively outputted. Under the action of the constant current reference signal, the power supply current outputted by the power conversion circuit is maintained at a stable current.22.一种控制芯片，其特征在于，所述芯片封装有如权利要求1至8任一所述的恒功率基准调制电路，或封装有如权利要求9至15任一所述的控制装置。22. A control chip, characterized in that the chip is packaged with the constant power reference modulation circuit according to any one of claims 1 to 8, or is packaged with the control device according to any one of claims 9 to 15.