High-current charging circuit and application method thereofTechnical Field
The invention belongs to the technical field of charging equipment, and particularly relates to a high-current charging circuit and a use method thereof.
Background
With the rapid development of electronic devices, consumers have increasingly demanded charging efficiency and convenience. In terms of charging technology, PD (Power Delivery) quick charging technology has become the mainstream in the market with its high power, high efficiency and wide compatibility. The PD specifies the voltage-current level of charging as a standard for charging using type_c. The standard for PD3.0 specifies a maximum charge power of 100W (20V/5A). According to the latest PD3.1 standard, the maximum charging power reaches 240W (48V/5A). The PD fast charging technology is mainly divided into PPS (Programmable Power Supply) protocol and non-PPS protocol. In the charging process, the voltage of the charging head is fixed after negotiation, and dynamic voltage regulation is not supported, so that the charging flexibility and efficiency are limited to a certain extent.
Aiming at the product adopting the non-type_c interface, the traditional charging circuit often has the problems of low charging efficiency, low charging speed, poor compatibility and the like. These products often rely on specific chargers and charging lines, cannot be compatible with a variety of charging devices, and cannot be intelligently adjusted according to the real-time state of the battery during charging, resulting in low charging efficiency.
In addition, since the products of the non-type_c interface are various, the charging interface and the charging standard are also different, which presents a great challenge to the design of the charging circuit. The conventional charging circuit often cannot meet the charging requirements of various interfaces and standards at the same time, so that the universality and the expandability of the charging equipment are poor.
Disclosure of Invention
Aiming at the problems of low charging efficiency, low charging speed, poor compatibility and the like of a charging circuit adopting a non-type_c interface product in the prior art, the invention provides a high-current charging circuit and a use method thereof, so as to solve the technical problems.
In a first aspect, the invention provides a high-current charging circuit, which comprises an adapter interface, a Buck-boost power supply unit, a charge pump charging unit, a Buck charging unit, a singlechip, a detection circuit and a battery interface;
The input end of the Buck-boost power supply unit and the input end of the detection circuit are connected to an external adapter through an adapter interface, the communication end of the Buck-boost power supply unit is connected to the first end of the single-chip microcomputer, the output end of the Buck-boost power supply unit is connected to the input end of the charge pump charging unit and the input end of the Buck charging unit, the output end of the detection circuit is connected to the second end of the single-chip microcomputer, the communication end of the charge pump charging unit and the communication end of the Buck charging unit are connected to the first end of the single-chip microcomputer, and the output end of the charge pump charging unit and the output end of the Buck charging unit are connected to an external battery to be charged through a battery charging interface.
The technical scheme is further improved, the BUCK-boost power supply unit comprises a voltage conversion chip with the model number TPS55287, an input pin of the voltage conversion chip is connected to an external adapter through an adapter interface, an enabling pin, a voltage programming pin and a current programming pin of the voltage conversion chip are connected to the singlechip through an I2C interface or an SPI interface, an output pin of the voltage conversion chip is connected to an input end of the charge pump charging unit and an input end of the BUCK charging unit, and the singlechip can control the voltage conversion chip to carry out output voltage programming and output current programming.
Further improvements in this technique are provided in which the step size of the programming output voltage is 10 millivolts and the step size of the programming output current is 50 milliamps.
According to a further improvement of the technical scheme, the charge pump charging unit comprises a battery charging chip with the model number of SC8571, the input voltage range of the charge pump charging unit is 6V-21V, and the output voltage range of the charge pump charging unit is 6V-10V.
The technical scheme is further improved, the Buck charging unit comprises a battery charging chip with the model of BQ25672, the battery charging chip in the Buck charging unit can detect battery voltage, battery current, battery temperature and input voltage of an external battery to be charged, and the battery charging chip is connected to the singlechip through an I2C interface or an SPI interface.
The technical scheme is further improved, and the singlechip is a singlechip with the model of STM32F103C8T 6.
The further improvement of this technical scheme still, detection circuitry includes resistance R1, operational amplifier U1, resistance R2, zener diode D1 and resistance R3, the first end of resistance R1 passes through adapter interface connection to outside adapter, the second end of resistance R1 is connected to operational amplifier U1's homophase input, operational amplifier U1's inverting input is connected to resistance R2's first end and zener diode D1's negative pole, zener diode D1's positive pole ground, the second end of resistance R2 is connected to outside Vcc power, operational amplifier U1's output is connected to the singlechip, operational amplifier U1's output is connected to operational amplifier U1's homophase input through resistance R3.
In a second aspect, the present invention provides a method for using the high-current charging circuit according to any one of the above, including:
When the singlechip detects that an external adapter is inserted through the detection circuit, the singlechip reads the power parameters of an external battery to be charged in the EEPROM chip and configures the output default voltage and current of the buck-boost power supply unit through the I2C interface;
the detection circuit detects whether the voltage of the inserted external adapter reaches a first preset voltage value Vth_in;
if yes, the output voltage of the detection circuit jumps from low level to high level;
When the singlechip detects that the output voltage of the detection circuit is high, controlling an enabling pin of the buck-boost power supply unit to pull high, and outputting configured default voltage and current by the buck-boost power supply unit;
the singlechip reads the voltage parameter of the external battery to be charged detected by the Buck charging unit through the I2C interface, and judges the charging stage of the external battery to be charged according to the read voltage parameter;
And configuring corresponding output voltage for the Buck-boost power supply unit according to the current charging stage of the external battery to be charged, and controlling the charging unit corresponding to the current charging stage to charge the external battery to be charged according to a preset rule after the configuration is finished, wherein the charging unit comprises a charge pump charging unit and a Buck charging unit.
According to the technical scheme, the method comprises the steps of configuring corresponding output voltage for a buck-boost power supply unit according to the current charging stage of an external battery to be charged, and controlling a charging unit corresponding to the current charging stage to charge the external battery to be charged according to a preset rule after the configuration is finished, wherein the method specifically comprises the following steps:
When the read voltage of the external battery to be charged is smaller than a second preset voltage value Vth_1 or larger than a third preset voltage value Vth_3, the third preset voltage value Vth_3 is larger than the second preset voltage value Vth_1, the external battery to be charged is judged to be in a trickle stage or a constant voltage charging stage, the singlechip configures the output voltage of the Buck-boost power supply unit to be a first preset output voltage Vout2 through an I2C interface, and the first preset output voltage Vout2 takes the intermediate value of the external adapter voltage and the current voltage of the external battery to be charged;
When the read voltage of the external battery to be charged is larger than a second preset voltage value Vth_1 and smaller than a third preset voltage value Vth_3, the external battery to be charged is judged to be in a constant current charging stage, the singlechip configures the output voltage of the Buck-boost power supply unit to be the second preset output voltage Vout3 through the I2C interface, the second preset output voltage Vout3 is 2 times of the current voltage of the external battery to be charged, the current is 6C, C is the charging and discharging multiplying power of the lithium battery, the singlechip controls the Buck charging unit to be closed, the enabling pin of the charge pump charging unit to be pulled high, and the charge pump charging unit charges the external battery to be charged.
Further improvement of the technical scheme also comprises:
In the process of charging an external battery to be charged through a charge pump charging unit, a singlechip regularly reads the charging voltage of the external battery to be charged detected in a Buck charging unit through an I2C interface, takes the read charging voltage of the external battery to be charged as a reference voltage, and adds 20mV on the basis of the reference voltage to be used for adjusting the output voltage of a Buck-boost power supply unit;
In the charging process of the external battery to be charged, the singlechip reads the battery temperature parameter of the external battery to be charged detected in the Buck charging unit through the I2C interface, when the read battery temperature parameter is larger than a first preset battery temperature value Vtem _h, the singlechip controls the Buck charging unit or the charge pump charging unit to stop charging through the I2C interface, and when the read battery temperature parameter is smaller than the first preset battery temperature value Vtem _l, the singlechip resumes charging.
The invention has the beneficial effects that:
The scheme does not need a specific charging protocol, such as PPS protocol, so that the charge pump can be quickly charged by using a common adapter, and the compatibility of charging equipment is greatly improved. Whether the product adopting the non-type_c interface or the device with different charging standards and interfaces is adopted, the high-current charging circuit can be used for efficiently and safely charging.
The invention can dynamically adjust the output voltage through the built-in buck-boost power supply unit so as to adapt to the requirements of different charging stages. The flexibility not only improves the charging efficiency, but also reduces the energy loss in the charging process and prolongs the service life of the battery.
Compared with the traditional charging scheme, the invention can enable the charging circuit to have larger charging current and charge the battery more quickly through the buck-boost power supply unit.
And the intelligent charging management is that the singlechip is communicated with the Buck-boost power supply unit, the charge pump charging unit and the Buck charging unit through an I2C or SPI interface, so that the information such as the charging state, the voltage, the current and the temperature of the battery can be read in real time. According to the information, the singlechip can intelligently adjust the charging strategy, and the safety and the high efficiency of the charging process are ensured.
In addition, the invention has reliable design principle, simple structure and very wide application prospect.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required to be used in the description of the embodiments or the prior art will be briefly described below, and it will be obvious to those skilled in the art that other drawings can be obtained from these drawings without inventive effort.
Fig. 1 is a schematic block diagram of a high current charging circuit of one embodiment of the invention.
Fig. 2 is a schematic diagram of a detection circuit.
Fig. 3 is a schematic flow chart of a method of one embodiment of the invention.
110 Is a Buck-boost power supply unit, 120 is a charge pump charging unit, 130 is a Buck charging unit, 140 is a singlechip, and 150 is a detection circuit.
Detailed Description
In order to make the technical solution of the present invention better understood by those skilled in the art, the technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without making any inventive effort, shall fall within the scope of the present invention.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.
The following explains key terms appearing in the present invention.
I2C interface, its English whole name is Inter-INTEGRATED CIRCUIT, its correspondent Chinese meaning is integrated circuit bus. This is a serial communication protocol, originally developed by Philips (now NXP semiconductors) in the 1980 s, for short-range, low-rate data transmission between Integrated Circuits (ICs). The I2C bus uses two lines, a Serial Clock (SCL) line and a Serial Data (SDA) line, to generate signals required by the I2C bus protocol for data transfer by controlling the high and low level timing on the two lines.
SPI interface, its English name is SERIAL PERIPHERAL INTERFACE, and its corresponding Chinese meaning is serial peripheral interface. This is a high-speed, full duplex, synchronous communication bus, and the standard SPI interface uses only 4 pins, including SCK (clock), MOSI (master-output-slave-input), MISO (master-input-slave-output), and SS (slave-select), some chips also called CS, CHIP SELECT). The method is mainly used for communication between a Microcontroller (MCU) and peripheral equipment such as EEPROM, FLASH, real-time clock (RTC), digital Signal Processor (DSP) and the like, and has the advantages of simplicity, easiness in use, high communication speed, support of a plurality of master-slave equipment and the like.
As shown in FIG. 1, the invention provides a high-current charging circuit, which comprises an adapter interface, a Buck-boost power supply unit, a charge pump charging unit, a Buck charging unit, a singlechip, a detection circuit and a battery interface, wherein the input end of the Buck-boost power supply unit and the input end of the detection circuit are connected to an external adapter through the adapter interface, the communication end of the Buck-boost power supply unit is connected to the first end of the singlechip, the output end of the Buck-boost power supply unit is connected to the input end of the charge pump charging unit and the input end of the Buck charging unit, the output end of the detection circuit is connected to the second end of the singlechip, the communication end of the charge pump charging unit and the communication end of the Buck charging unit are both connected to the first end of the singlechip, and the output end of the charge pump charging unit and the output end of the Buck charging unit are both connected to an external battery to be charged through the battery charging interface.
The BUCK-boost power supply unit comprises a voltage conversion chip with the model number of TPS55287 and external components such as capacitance, inductance and resistance required by normal operation of the chip, wherein an input pin of the voltage conversion chip is connected to an external adapter through an adapter interface, an enabling pin, a voltage programming pin and a current programming pin of the voltage conversion chip are connected to a singlechip through an I2C interface or an SPI interface, the singlechip can control the working state of the unit through controlling the enabling pin of the voltage conversion chip, an output pin of the voltage conversion chip is connected to an input end of a charge pump charging unit and an input end of the BUCK charging unit, and the singlechip can control the voltage conversion chip to carry out output voltage programming and output current programming. The step size of the programming output voltage is 10 millivolts, and the step size of the programming output current is 50 milliamps. The main function of the unit is to convert the input voltage of the external adapter to a suitable voltage for charging an external battery to be charged, including a lithium battery.
In addition, the charge pump charging unit comprises a battery charging chip with the model of SC8571 and peripheral devices such as resistors, capacitors and the like required by the normal operation of the chip, the battery charging chip is a 4:2 charging chip, the input voltage range of the chip is 6V-21V, the output voltage range of the chip is 6V-10V, and in addition, the battery charging chip has protection functions such as input voltage overvoltage, input current overcurrent, output voltage overvoltage, battery current overcurrent and the like, and can output interrupt signals when the functions trigger protection.
In addition, the Buck charging unit comprises a battery charging chip with the model of BQ25672 and peripheral devices such as resistance, capacitance and inductance required by normal operation of the chip, wherein the battery charging chip in the Buck charging unit can detect battery voltage, battery current, battery temperature and input voltage of an external battery to be charged, and the battery charging chip is connected to the singlechip through an I2C interface or an SPI interface. In addition, the battery charging chip is provided with an enabling pin which is used for controlling whether the battery charging chip starts to charge the lithium battery or not.
Further, the singlechip adopts a singlechip with the model of STM32F103C8T6, and devices such as a resistor, a capacitor, a crystal oscillator, a power supply and the like required by the normal work of the chip. Meanwhile, the single chip microcomputer is externally connected with an EEPROM chip and is used for storing specification parameters of an external battery to be charged.
As shown in fig. 2, the detection circuit includes a resistor R1, an operational amplifier U1, a resistor R2, a zener diode D1 and a resistor R3, wherein a first end of the resistor R1 is connected to an external adapter through an adapter interface, a second end of the resistor R1 is connected to a non-inverting input end of the operational amplifier U1, an inverting input end of the operational amplifier U1 is connected to the first end of the resistor R2 and a negative electrode of the zener diode D1, an anode of the zener diode D1 is grounded, a second end of the resistor R2 is connected to an external Vcc power supply, an output end of the operational amplifier U1 is connected to a singlechip, and an output end of the operational amplifier U1 is connected to a non-inverting input end of the operational amplifier U1 through the resistor R3.
As shown in fig. 3, the present invention provides a method for using the high-current charging circuit according to any one of the above, including:
step 310, when the singlechip detects that an external adapter is inserted through a detection circuit, the singlechip reads the power parameters of an external battery to be charged in the EEPROM chip and configures the output default voltage and current of a buck-boost power supply unit through an I2C interface;
Step 320, the detection circuit detects whether the voltage of the inserted external adapter reaches a first preset voltage value Vth_in, if yes, the step 330 is shifted to;
Step 330, the output voltage of the detection circuit jumps from low level to high level;
Step 340, when the singlechip detects that the output voltage of the detection circuit is at a high level, controlling an enable pin of the buck-boost power supply unit to pull the high level, and outputting configured default voltage and current by the buck-boost power supply unit;
step 350, the singlechip reads the voltage parameter of the external battery to be charged detected by the Buck charging unit through the I2C interface, and judges the charging stage of the external battery to be charged according to the read voltage parameter;
And step 360, configuring corresponding output voltage for the Buck-boost power supply unit according to the current charging stage of the external battery to be charged, and after the configuration is finished, controlling a charging unit corresponding to the current charging stage to charge the external battery to be charged according to a preset rule, wherein the charging unit comprises a charge pump charging unit and a Buck charging unit.
Specifically, a corresponding output voltage is configured for a buck-boost power supply unit according to a charging stage in which an external battery to be charged is currently located, and after the configuration is completed, a charging unit corresponding to the current charging stage is controlled to charge the external battery to be charged according to a preset rule, and the method comprises the following steps:
When the read voltage of the external battery to be charged is smaller than a second preset voltage value Vth_1 or larger than a third preset voltage value Vth_3, the third preset voltage value Vth_3 is larger than the second preset voltage value Vth_1, the external battery to be charged is judged to be in a trickle stage or a constant voltage charging stage, the singlechip configures the output voltage of the Buck-boost power supply unit to be a first preset output voltage Vout2 through an I2C interface, and the first preset output voltage Vout2 takes the intermediate value of the external adapter voltage and the current voltage of the external battery to be charged;
When the read voltage of the external battery to be charged is larger than a second preset voltage value Vth_1 and smaller than a third preset voltage value Vth_3, the external battery to be charged is judged to be in a constant current charging stage, the singlechip configures the output voltage of the Buck-boost power supply unit to be the second preset output voltage Vout3 through the I2C interface, the second preset output voltage Vout3 is 2 times of the current voltage of the external battery to be charged, the current is 6C, C is the charging and discharging multiplying power of the lithium battery, the singlechip controls the Buck charging unit to be closed, the enabling pin of the charge pump charging unit to be pulled high, and the charge pump charging unit charges the external battery to be charged.
In addition, the using method further comprises the steps that in the process of charging the external battery to be charged through the charge pump charging unit, the singlechip regularly reads charging voltage, charging current and battery temperature information of the external battery to be charged detected in the Buck charging unit through the I2C interface, the read charging voltage of the external battery to be charged is taken as a reference voltage, and the read charging voltage is added by 20mV on the basis of the reference voltage to be used as the output voltage of the Buck-boost power supply unit.
In addition, the use method further comprises the steps that in the charging process of the external battery to be charged, the singlechip reads the battery temperature parameter of the external battery to be charged detected in the Buck charging unit through the I2C interface, when the read battery temperature parameter is larger than a first preset battery temperature value Vtem _h, the singlechip controls the Buck charging unit or the charge pump charging unit to stop charging through the I2C interface, and when the read battery temperature parameter is smaller than the first preset battery temperature value Vtem _l, the singlechip resumes charging.
Although the present invention has been described in detail by way of preferred embodiments with reference to the accompanying drawings, the present invention is not limited thereto. Various equivalent modifications and substitutions may be made in the embodiments of the present invention by those skilled in the art without departing from the spirit and scope of the present invention, and it is intended that all such modifications and substitutions be within the scope of the present invention/be within the scope of the present invention as defined by the appended claims.