CN114513128A - Current supply system and method of operation, associated integrated circuit and power supply system - Google Patents

Abstract

The invention relates to a current supply system, an operation method thereof, a related integrated circuit and a power supply system. A control circuit for a voltage source generates a reference signal for the voltage source, wherein the reference signal is indicative of a requested output voltage to be generated by the voltage source. The digital feedforward control circuit calculates a digital feedforward adjustment value indicative of the requested output voltage by determining a maximum voltage drop at the string of solid state light sources. A digital feedback control circuit determines a minimum voltage drop for the current regulator/limiter of the string and determines a digital feedback correction value based on the minimum voltage drop. Then, the control circuit sets the reference signal after the startup according to the digital feedforward adjustment value, and corrects the reference signal according to the digital feedback correction value.

Description

Translated fromChinese

电流供应系统及其操作方法、相关集成电路和电源系统Current supply system and method of operation, associated integrated circuit and power supply system

优先权要求priority claim

本申请要求在2020年11月17日提交的意大利专利102020000027504号申请的优先权权益，其内容通过引用以法律允许的最大程度整体并入本文。This application claims the benefit of priority from Italian Patent Application No. 102020000027504, filed on November 17, 2020, the contents of which are hereby incorporated by reference in their entirety to the fullest extent permitted by law.

技术领域technical field

本公开的实施例涉及用于减少发光二极管或类似固态光源的电源系统中的功率损耗的解决方案。Embodiments of the present disclosure relate to solutions for reducing power losses in power supply systems for light emitting diodes or similar solid state light sources.

背景技术Background technique

电源电路，例如AC/DC或DC/DC开关模式电源在本领域中是公知的。存在许多类型的电子转换器，其主要分为隔离式转换器和非隔离式转换器。例如，非隔离式电子转换器是“降压”、“升压”、“降压-升压”、

“SEPIC”和“ZETA”类型的转换器。相反，隔离式转换器是例如“反激”、“正向”、“半桥”和“全桥”类型的转换器。这种类型的转换器是本领域技术人员众所周知的，如(例如)由应用注释AN513/0393“用于开关模式电源的拓扑”，L.Wuidart、1999，意法半导体(通过引用并入本文)所证明的。Power supply circuits, such as AC/DC or DC/DC switch mode power supplies, are well known in the art. There are many types of electronic converters, which are mainly divided into isolated converters and non-isolated converters. For example, non-isolated electronic converters are "buck", "boost", "buck-boost",

Converters of type "SEPIC" and "ZETA". In contrast, isolated converters are eg "flyback", "forward", "half bridge" and "full bridge" types of converters. Converters of this type are well known to those skilled in the art, as, for example, by application note AN513/0393 "Topologies for Switched Mode Power Supplies", L. Wuidart, 1999, STMicroelectronics (incorporated herein by reference) proven.

图1是DC/DC电子转换器20的示意图。尤其，通用电子转换器20包括用于接收DC电压Vin的两个输入端子200a和200b以及用于提供DC电压Vout的两个输出端子202a和202b。例如，输入电压Vin可以由诸如电池的DC电压源10提供，或者可以借助于诸如桥式整流器的整流器电路以及可能的滤波电路从AC电压获得。相反，输出电压Vout可以用于向负载30供电。FIG. 1 is a schematic diagram of a DC/DCelectronic converter 20 . In particular, the universalelectronic converter 20 comprises twoinput terminals 200a and 200b for receiving the DC voltage Vin and twooutput terminals 202a and 202b for providing the DC voltage Vout. For example, the input voltage Vin may be provided by aDC voltage source 10 such as a battery, or may be obtained from an AC voltage by means of a rectifier circuit such as a bridge rectifier and possibly a filter circuit. Instead, the output voltage Vout can be used to power theload 30 .

如公知的，电子转换器包括一个或多个电抗组件，例如电感和/或电容，以及一个或多个电子开关，电子开关被配置成控制：从输入端子200a和200b到一个或多个电抗组件的电流流动、和/或从一个或多个电抗组件到输出端子202a和202b的电流流动。As is known, an electronic converter includes one or more reactive components, such as inductors and/or capacitors, and one or more electronic switches configured to control: from theinput terminals 200a and 200b to the one or more reactive components and/or from one or more reactive components to theoutput terminals 202a and 202b.

例如，图2示出典型的电子转换器20a。具体地，电子转换器20a包括连接在输入端子200a、200b与输出端子202a、202b之间的开关级/电路28。这种开关级28包括一个或多个电抗组件，例如一个或多个电感L、例如电感器或变压器，和/或一个或多个电容器C。此外，开关级28包括一个或多个电子开关，诸如开关Q1和Q2，电子开关被配置成控制流过一个或多个电抗组件的一个或多个电流。例如，在典型的电子转换器中，一个或多个电子开关用于控制流经电感L的电流，电感L例如是电感器(例如，在升压、降压或降压-升压转换器的情况下)或变压器(例如，在反激、正向或半桥转换器的情况下)。For example, Figure 2 shows a typicalelectronic converter 20a. Specifically, theelectronic converter 20a includes a switching stage/circuit 28 connected between theinput terminals 200a, 200b and theoutput terminals 202a, 202b.Such switching stage 28 includes one or more reactive components, such as one or more inductances L, such as inductors or transformers, and/or one or more capacitors C. Additionally, switchingstage 28 includes one or more electronic switches, such as switches Q1 and Q2, that are configured to control one or more currents flowing through one or more reactive components. For example, in a typical electronic converter, one or more electronic switches are used to control the current flowing through an inductor L, such as an inductor (eg, in a boost, buck, or buck-boost converter). case) or a transformer (for example, in the case of a flyback, forward or half-bridge converter).

电子转换器20a通常还包括控制电路22a，控制电路被配置成驱动一个或多个电子开关的开关，以便获得所请求的输出电压V_out。Theelectronic converter 20a also typically includes acontrol circuit 22a configured to drive the switches of one or more electronic switches in order to obtain the requested output voltage_Vout .

例如，为此目的，电子转换器20a可以包括反馈(FBC)电路24，例如分压器，反馈(FBC)电路被配置成生成指示输出电压V_out(并且优选与输出电压成比例)的反馈信号FB，并且控制电路22a被配置成通过将反馈信号FB与参考信号(例如参考电压V_ref)进行比较来生成用于一个或多个电子开关的驱动信号。For example, for this purpose, theelectronic converter 20a may include a feedback (FBC)circuit 24, such as a voltage divider, configured to generate a feedback signal indicative of (and preferably proportional to) the output voltage_Vout FB, and thecontrol circuit 22a is configured to generate a drive signal for one or more electronic switches by comparing the feedback signal FB with a reference signal (eg, a reference voltage_Vref ).

例如，如本领域所公知的，开关级28可以被配置成使得流经电感L的电流可以在连续导通模式(CCM)、不连续导通模式(DCM)或过渡模式(TM)中(经由一个或多个电子开关)被控制。For example, as is known in the art, switchingstage 28 may be configured such that the current flowing through inductor L may be in continuous conduction mode (CCM), discontinuous conduction mode (DCM), or transition mode (TM) (via one or more electronic switches) are controlled.

例如在CCM中，控制电路22a通常以包括两个开关阶段的开关时段来驱动开关级28的电子开关(使用驱动器电路220)，其中：在第一阶段期间，流经电感L的电流增加；并且在第二阶段期间，流经电感L的电流减小。In CCM, for example, thecontrol circuit 22a typically drives the electronic switches of the switching stage 28 (using the driver circuit 220) with a switching period comprising two switching phases, wherein: during the first phase, the current through the inductor L increases; and During the second phase, the current through the inductor L decreases.

相反地，在DCM中，控制电路22a通常以包括三个开关阶段的开关时段来驱动开关级28的电子开关，其中：在第一阶段期间，流经电感L的电流增加；在第二阶段期间，流经电感L的电流减小，其中当流经电感L的电流达到零时，第二阶段结束；并且在第三阶段期间，流经电感L的电流保持为零。Conversely, in DCM, thecontrol circuit 22a typically drives the electronic switches of theswitching stage 28 with a switching period comprising three switching phases, wherein: during the first phase the current through the inductor L increases; during the second phase , the current through the inductor L decreases, wherein the second phase ends when the current through the inductor L reaches zero; and during the third phase, the current through the inductor L remains zero.

例如在DCM中，第三阶段的开始可以是转换器拓扑所固有的(例如，通过使用一个或多个二极管，当流经电感L的电流达到零时该二极管自动断开)，或者如图2所示，通过使用零电流检测(ZCD)电路26，该电路被配置成通过监控指示流经电感L的电流(并且优选地与该电流成比例)的信号CS来生成零电流信号ZC。In DCM, for example, the onset of the third phase can be inherent to the converter topology (eg, by using one or more diodes that automatically turn off when the current through the inductor L reaches zero), or as shown in Figure 2 As shown, using a zero current detection (ZCD)circuit 26 configured to generate a zero current signal ZC by monitoring a signal CS indicative of (and preferably proportional to) the current flowing through the inductor L.

通常，大量的驱动方案在本领域中是已知的。例如，在各种已知的解决方案中，开关周期T_SW的持续时间可以是恒定的，并且第一阶段的持续时间可以经由比例积分(PI)或比例积分微分(PID)调节器来确定，比例积分(PI)或比例积分微分(PID)调节器被配置成调节参考信号V_ref与由反馈电路24提供的反馈信号FB之间的差。例如，这通过PWM生成器电路220示意地示出，该PWM生成器电路被配置成生成PWM信号DRV，该PWM信号具有开关周期T_SW(例如，具有固定或预定的时段)，其中信号DRV在第一持续时间T_ON内被设置为第一逻辑电平(例如，高电平)，在第二持续时间T_OFF内被设置为第二逻辑电平(例如，低电平)，其中T_SW＝T_ON+T_OFF(也参见图3)。例如，电路220可以是模拟和/或数字PI或PID调节器，其被配置成改变接通持续时间T_ON以便将参考信号V_ref与反馈信号FB之间的差调节为零。In general, a large number of drive schemes are known in the art. For example, in various known solutions, the duration of the switching period T_SW may be constant, and the duration of the first phase may be determined via a proportional-integral (PI) or proportional-integral-derivative (PID) regulator, A proportional-integral (PI) or proportional-integral-derivative (PID) regulator is configured to regulate the difference between the reference signal V_ref and the feedback signal FB provided by thefeedback circuit 24 . This is illustrated schematically, for example, by a PWM generator circuit 220 that is configured to generate a PWM signal DRV having a switching period T_SW (eg, having a fixed or predetermined period), wherein the signal DRV is at is set to a first logic level (eg, a high level) for a first duration T_ON and a second logic level (eg, a low level) for a second duration T_OFF , where T_SW =T_ON +T_OFF (see also Figure 3). For example, the circuit 220 may be an analog and/or digital PI or PID regulator configured to vary the on-time duration T_ON in order to regulate the difference between the reference signal V_ref and the feedback signal FB to zero.

因此，在所考虑的示例中，电子转换器20、20a是被配置成提供经调节的输出电压V_out的电压源。这种电压源也可以用于提供恒定电流负载。例如，图4A和图4B示出典型的情况，其中，(调节)电压源20用于向给定数量n的并联连接的发光二极管(LED)串34供电，其中每个LED串包括给定数量N的LED或类似的固态光源L，诸如激光二极管或OLED(有机发光二极管)。例如，在图4A和图4B中示出4个串，其中：第一串包括五个光源L；第二串包括四个光源L；第三串包括三个光源L；第四串包括两个光源L。Thus, in the example considered, theelectronic converter 20, 20a is a voltage source configured to provide a regulated output voltage V_out . This voltage source can also be used to provide constant current loads. For example, Figures 4A and 4B illustrate a typical situation where a (regulated)voltage source 20 is used to power a given number n of parallel-connected light emitting diode (LED)strings 34, where each LED string includes a given number N LEDs or similar solid state light sources L, such as laser diodes or OLEDs (Organic Light Emitting Diodes). For example, 4 strings are shown in Figures 4A and 4B, wherein: the first string includes five light sources L; the second string includes four light sources L; the third string includes three light sources L; the fourth string includes two Light source L.

例如，这种串34可以用作LCD面板的背景照明，或者通常用于其中必须单独控制流过每个串34的电流的任何应用中。Such strings 34 may be used, for example, as backlighting for LCD panels, or generally in any application where the current flowing through eachstring 34 must be individually controlled.

此外，如图5所示，通常也可以单独地控制流过给定串34的每个光源L的电流。例如，为此目的，每个光源L可以并联连接相应的电子开关Sw，即，用于给定串34的光源L1、...、LN的开关SW1、...、SWN，其中每个电子开关通过各自的驱动信号Sw_ctrl1、...、Sw_ctrlN来驱动。因此，通过还使用光源L的单独控制，LED串也可以用作有源LED或OLED面板。Furthermore, as shown in FIG. 5 , the current flowing through each light source L of a givenstring 34 can also generally be individually controlled. For example, for this purpose, each light source L may be connected in parallel with a corresponding electronic switch Sw, ie the switches SW1 , . . . , SWN for the light sources L1 , . The switches are driven by respective drive signals Sw_ctrl1, . . . , Sw_ctrlN. Thus, by also using individual control of the light source L, the LED string can also be used as an active LED or OLED panel.

因此，在许多应用中：各个串34的固态光源的数量N可以不同；和/或一个或多个串34的接通的固态光源L的数量可以随时间变化。Thus, in many applications: the number N of solid state light sources for eachstring 34 may vary; and/or the number of solid state light sources L that are turned on for one ormore strings 34 may vary over time.

然而，这意味着在各个并联连接的LED串34处的电压降可以彼此不同和/或可以随时间变化。此外，电压降也可能由于制造公差、温度(尤其是在OLED面板的情况下)和老化而变化。为此，LED串通常不是直接经由电压源20提供的电压V_out供电，而是电流调节器/限制器32与每个LED串34串联连接。However, this means that the voltage drops at the individual parallel connectedLED strings 34 may differ from each other and/or may vary over time. Furthermore, the voltage drop may also vary due to manufacturing tolerances, temperature (especially in the case of OLED panels) and aging. For this reason, the LED strings are typically not powered directly via the voltage V_out provided by thevoltage source 20 , but a current regulator/limiter 32 is connected in series with eachLED string 34 .

例如，在图4A中，每个LED串34的正端子连接(例如，直接连接)到正输出端子202A，并且每个LED串34的负端子经由相应的电流调节器/限制器32(即，电流吸收器)连接(例如，直接连接)到负输出端子202b。相反，在图4B中，每个LED串34的负端子连接(例如，直接连接)到负输出端子202b，并且每个LED串34的正端子经由相应的电流调节器/限制器32(即电流源)连接(例如，直接地连接)到正输出端子202a。For example, in Figure 4A, the positive terminal of eachLED string 34 is connected (eg, directly connected) to the positive output terminal 202A, and the negative terminal of eachLED string 34 is connected via a corresponding current regulator/limiter 32 (ie, current sink) is connected (eg, directly connected) to thenegative output terminal 202b. In contrast, in Figure 4B, the negative terminal of eachLED string 34 is connected (eg, directly connected) to thenegative output terminal 202b, and the positive terminal of eachLED string 34 is connected via a corresponding current regulator/limiter 32 (ie, current source) is connected (eg, directly connected) to thepositive output terminal 202a.

因此，每个电流调节器/限制器32被配置成将流过相应LED串34的电流值设置(在调节器的情况下)或限制(在电流限制器的情况下)到例如用于第一串的值I₁、用于第二串的值I₂、等等。例如，通常每个电流调节器/限制器32被配置成根据控制信号CTRL设置相应的电流，例如：将所述相应电流设定为零，从而关断所述相应LED串；或者将相应的电流设置为给定(固定或可以设置的)值，从而接通(激活)相应的LED串，其中由相应的LED串发射的光的亮度取决于给定值。Thus, each current regulator/limiter 32 is configured to set (in the case of a regulator) or limit (in the case of a current limiter) the value of the current flowing through thecorresponding LED string 34 to, for example, a first The value I₁ for the string, the value I₂ for the second string, and so on. For example, typically each current regulator/limiter 32 is configured to set a corresponding current according to the control signal CTRL, eg: to set the corresponding current to zero, thereby turning off the corresponding LED string; or to set the corresponding current to Set to a given (fixed or settable) value, thereby turning on (activating) the corresponding LED string, wherein the brightness of the light emitted by the corresponding LED string depends on the given value.

通常，如所公知的，以这种方式，通过控制由各种光源L发射的光的强度，也可以设置由LED串发射的光的颜色。In general, in this way, by controlling the intensity of the light emitted by the various light sources L, the color of the light emitted by the LED string can also be set, as is well known.

例如，为此目的，每个电流调节器/限制器32可以被配置成根据一个或多个(模拟和/或数字)控制信号(诸如用于第一电流调节器/限制器32的控制信号CTRL1、用于第二电流调节器/限制器32的控制信号CTRL2等)接通或关断相应的LED串和/或设置相应电流的值。通常，除了前面讨论的问题外，流过LED串的电流的不同值的设置通常也暗示每个发光元件L处的电压降可以随时间变化。For example, each current regulator/limiter 32 may be configured for this purpose in accordance with one or more (analog and/or digital) control signals, such as control signal CTRL1 for the first current regulator/limiter 32 , control signal CTRL2 for the second current regulator/limiter 32, etc.) to turn on or off the corresponding LED string and/or set the value of the corresponding current. In general, in addition to the issues discussed above, the setting of different values of the current through the LED string usually also implies that the voltage drop at each light emitting element L can vary over time.

例如，通过使用用于控制信号CTRL的脉宽调制(PWM)信号，由给定串34的光源发射的光的(平均)强度取决于相应PWM信号CTRL的占空比。类似地，通过使用信号Sw_ctrl1、...、Sw_ctrlN的PWM信号，由给定串34的每个光源发射的光的(平均)强度取决于相应PWM信号Sw_ctrl的占空比。For example, by using a pulse width modulated (PWM) signal for the control signal CTRL, the (average) intensity of light emitted by the light sources of a givenstring 34 depends on the duty cycle of the corresponding PWM signal CTRL. Similarly, by using the PWM signals of signals Sw_ctrl1, . . . , Sw_ctrlN, the (average) intensity of light emitted by each light source of a givenstring 34 depends on the duty cycle of the corresponding PWM signal Sw_ctrl.

因此，通常电流调节器/限制器32的给定(最大)值是固定的，并且光源34的亮度经由PWM信号CTRL和/或Sw_CTRL、通过接通和关断所述串34和/或各个光源L来控制。实际上，电流调节器/限制器32被配置成设置流过每个LED串34的电流值。此外可选地，每个LED串34的各种光源也可以单独地接通或关断，由此电流可以仅流过光源的子集，即，电流调节器/限制器32被配置成设置用于相应LED串的全局电流，并且附加开关可以用于使流过该串的光源中的一个或多个光源的电流无效。Therefore, typically the given (maximum) value of the current regulator/limiter 32 is fixed, and the brightness of thelight sources 34 via the PWM signals CTRL and/or Sw_CTRL, by switching thestring 34 and/or individual light sources on and off L to control. In effect, the current regulator/limiter 32 is configured to set the value of the current flowing through eachLED string 34 . Also optionally, the various light sources of eachLED string 34 can also be turned on or off individually, whereby current can flow through only a subset of the light sources, ie, the current regulator/limiter 32 is configured to set the The global current to the corresponding LED string, and additional switches may be used to disable current flow through one or more of the string's light sources.

通常，电流调节器/限制器32是线性电流调节器，这因此意味着相应LED串处的电压V_out与电压降之间的差被施加到电流调节器/限制器32，这基本耗散了过量的功率，从而生成电损耗。Typically, the current regulator/limiter 32 is a linear current regulator, which therefore means that the difference between the voltage_Vout at the respective LED string and the voltage drop is applied to the current regulator/limiter 32, which substantially dissipates Excessive power, thereby generating electrical losses.

为此，通常优选地将电压V_out维持在略高于LED串处的最大电压降。因此，在电压V_out固定的情况下，电压V_out必须等于(或大于)需要最大供电电压的最坏情况。相反，自适应系统也是例如从美国专利申请公开号2004/0233144或2010/0156315或美国专利号6,864,641已知的，所有这些美国专利申请公开都通过引用并入本文，其中，输出电压V_out的值根据LED串34或电流调节器/限制器32处的电压降而变化。For this reason, it is generally preferable to maintain the voltage V_out slightly above the maximum voltage drop at the LED string. Therefore, with the voltage V_out fixed, the voltage V_out must be equal to (or greater than) the worst case where the maximum supply voltage is required. In contrast, adaptive systems are also known, for example, from US Patent Application Publication Nos. 2004/0233144 or 2010/0156315 or US Patent No. 6,864,641, all of which are incorporated herein by reference, wherein the value of the output voltage V_out Varies according to the voltage drop at theLED string 34 or the current regulator/limiter 32 .

这种解决方案通常包括校准阶段，其中确定LED串34处的最大电压降。例如为此目的，通过一次一个地接通LED串或者同时接通所有LED串，LED面板的操作功能被校准过程本身周期性地中断。Such solutions typically include a calibration phase in which the maximum voltage drop at theLED string 34 is determined. For this purpose, for example, by switching on the LED strings one at a time or all LED strings simultaneously, the operating function of the LED panel is periodically interrupted by the calibration process itself.

然而，在LED用于发信号通知危险情况的情形下，例如在汽车行业中，例如在尾灯的情况下，这些方法代表了LED系统的显著限制，该尾灯应当能够发信号通知突然制动或方向指示器。此外例如，在有源LED面板的情况下，每串的激活光源的数量可能频繁变化，由此最坏情况的假设仍然生成显著的功率损耗。However, in situations where LEDs are used to signal dangerous situations, such as in the automotive industry, for example in the case of taillights, these approaches represent a significant limitation of LED systems, which should be able to signal sudden braking or direction indicator. Also, for example, in the case of active LED panels, the number of activated light sources per string may vary frequently, whereby worst-case assumptions still generate significant power losses.

鉴于上述情况，在本领域中需要提供用于基于实际负载需求来动态地适配电压源的输出电压的解决方案。In view of the above, there is a need in the art to provide a solution for dynamically adapting the output voltage of a voltage source based on actual load demands.

发明内容SUMMARY OF THE INVENTION

根据一个或多个实施例，提供了一种电流供应系统。实施例还涉及相关的集成电路、电源系统和操作电流供应系统的方法。According to one or more embodiments, a current supply system is provided. Embodiments also relate to related integrated circuits, power supply systems, and methods of operating current supply systems.

本公开的各种实施例涉及例如在集成电路中实现的电流供应系统。Various embodiments of the present disclosure relate to current supply systems implemented, for example, in integrated circuits.

具体地，在各种实施例中，电流供应系统包括被配置成连接到电压源的第一输出端子上的一个或多个第一端子以及多个第二端子，其中，第二端子中的每个第二端子被配置成经由相应固态光源串连接到电压源的第二输出端子。Specifically, in various embodiments, the current supply system includes one or more first terminals and a plurality of second terminals configured to be connected to a first output terminal of a voltage source, wherein each of the second terminals The second terminals are configured to be connected to the second output terminals of the voltage source via the respective strings of solid state light sources.

在各种实施例中，电流供应系统包括多个电流调节器或限制器，其中，第二端子中的每个第二端子经由相应的电流调节器或限制器连接到一个或多个第一端子中的至少一个第一端子，其中，所述电流调节器或限制器中的每个电流调节器或限制器被配置成将流经连接到相应第二端子的固态光源串的电流限制到相应最大值。因此，电流供应系统可以用于限制也包括电压源和可选地固态光源串的电源系统中的电流流动。In various embodiments, the current supply system includes a plurality of current regulators or limiters, wherein each of the second terminals is connected to one or more of the first terminals via a respective current regulator or limiter at least one first terminal in, wherein each of the current regulators or limiters is configured to limit the current flowing through the string of solid state light sources connected to the corresponding second terminal to a corresponding maximum value. Thus, the current supply system can be used to limit current flow in a power supply system that also includes a voltage source and optionally a string of solid state light sources.

在各种实施例中，电流供应系统还包括第三端子，第三端子被配置成向电压源提供参考信号，其中，参考信号指示将由电压源在电压源的第一输出端子和第二输出端子之间生成的所请求的输出电压。因此，控制电路可以被配置成生成该参考信号。In various embodiments, the current supply system further includes a third terminal configured to provide a reference signal to the voltage source, wherein the reference signal indicates that the voltage source is to be supplied by the voltage source at the first output terminal and the second output terminal of the voltage source generated between the requested output voltages. Accordingly, the control circuit may be configured to generate the reference signal.

具体地，在各种实施例中，控制电路包括至少一个模数转换器和数模转换器转换电路。具体地，至少一个模数转换器被配置成获得第二端子处的电压和电压源的第一输出端子与第二输出端子之间的电压(即，由电压源生成的输出电压)的数字样本。数模转换器转换电路被配置成接收数字调节值并且在输出处向第三端子/电压源提供参考信号。Specifically, in various embodiments, the control circuit includes at least one analog-to-digital converter and a digital-to-analog converter conversion circuit. Specifically, the at least one analog-to-digital converter is configured to obtain digital samples of the voltage at the second terminal and the voltage between the first and second output terminals of the voltage source (ie, the output voltage generated by the voltage source). . The digital-to-analog converter conversion circuit is configured to receive the digital adjustment value and provide a reference signal at the output to the third terminal/voltage source.

例如，通常参考信号可以用于设置电压源的参考电压，例如，参考信号可以与将由电压源生成的所请求的输出电压成比例。在这种情况下，数模转换器转换电路可以包括模数转换器，模数转换器被配置成根据数字调节值直接生成参考信号。然而，参考信号也可以用于改变电压源的反馈信号。例如，在这种情况下，第三端子可以耦联到电压源的反馈端子，以便改变指示由电压源生成的输出电压的反馈信号。For example, typically a reference signal may be used to set the reference voltage of the voltage source, eg, the reference signal may be proportional to the requested output voltage to be generated by the voltage source. In this case, the digital-to-analog converter conversion circuit may comprise an analog-to-digital converter configured to generate the reference signal directly from the digital adjustment value. However, the reference signal can also be used to vary the feedback signal of the voltage source. For example, in this case, the third terminal may be coupled to the feedback terminal of the voltage source in order to vary the feedback signal indicative of the output voltage generated by the voltage source.

在各种实施例中，控制电路包括数字前馈控制电路和数字反馈控制电路两者。In various embodiments, the control circuit includes both a digital feedforward control circuit and a digital feedback control circuit.

在各种实施例中，前馈控制电路被配置成通过根据数字样本确定第二端子与电压源的第二输出端子之间(即，在固态光源的串处)的最大电压降并且通过将给定的裕量加到该最大电压降来计算指示所请求的输出电压的数字前馈调节值。In various embodiments, the feedforward control circuit is configured by determining the maximum voltage drop between the second terminal and the second output terminal of the voltage source (ie, at the string of solid state light sources) from the digital samples and by giving the A certain margin is added to this maximum voltage drop to calculate a digital feedforward regulation value indicative of the requested output voltage.

相反，在各种实施例中，反馈控制电路被配置成根据数字样本确定多个电流调节器或限制器处的最小电压降并且根据最小电压降和裕量之间的差确定反馈校正值。Rather, in various embodiments, the feedback control circuit is configured to determine the minimum voltage drop at the plurality of current regulators or limiters from the digital samples and to determine the feedback correction value from the difference between the minimum voltage drop and the headroom.

在各种实施例中，控制电路被配置成响应于电流供应系统的启动，将数字调节值设置成指示所请求的最大输出电压的第一值，即，最初电压源提供最大供电电压。In various embodiments, the control circuit is configured to, in response to activation of the current supply system, set the digital adjustment value to a first value indicative of the requested maximum output voltage, ie, initially the voltage source provides the maximum supply voltage.

在各种实施例中，控制电路然后被配置成确定数字调节值是否对应于第一(最大)值。在这种情况下，控制电路根据前馈值设置数字调节值，例如，将数字调节值设置为前馈值，由此电压源从最大值“跳”到与前馈值相对应的新的输出电压。相反地，当数字调节值不对应于第一值时(例如，因为已经使用了前馈值)，控制电路可以将反馈校正值加到数字调节值，从而实现输出电压的微调。In various embodiments, the control circuit is then configured to determine whether the digital adjustment value corresponds to the first (maximum) value. In this case, the control circuit sets the digital adjustment value according to the feedforward value, e.g. the digital adjustment value is set to the feedforward value, whereby the voltage source "jumps" from the maximum value to a new output corresponding to the feedforward value Voltage. Conversely, when the digital adjustment value does not correspond to the first value (eg, because a feedforward value has been used), the control circuit may add a feedback correction value to the digital adjustment value, thereby enabling fine adjustment of the output voltage.

通常，控制电路也可以检测各种事件并且将数字调节值设置为最大值(从而重新激活前馈控制)或者最小值(从而使对固态光源串的电流供应无效)。Typically, the control circuit can also detect various events and set the digital adjustment value to a maximum value (thus reactivating the feedforward control) or a minimum value (thus deactivating the current supply to the solid state light source string).

例如，在各种实施例中，电流调节器或限制器中的每个被配置成从控制电路接收指示至少第一操作模式和第二操作模式的至少一个控制信号。例如，当至少一个控制信号指示第一操作模式时，相应的电流调节器或限制器可以被配置成使所述电流无效。相反，当所述至少一个控制信号指示第二操作模式时，相应的电流调节器或限制器可以被配置成将电流限制到相应的最大值。例如为此目的，所述至少一个控制信号可以包括脉宽调制信号，其中，脉宽调制信号的第一逻辑电平指示第一操作模式，并且脉宽调制信号的第二逻辑电平指示第二操作模式。通常，至少一个控制信号也可以指示最大值。例如，这样的控制信号可以用于选择性地接通或关断所述串和/或执行对由光源发射的光进行调光。For example, in various embodiments, each of the current regulator or limiter is configured to receive at least one control signal from the control circuit indicative of at least a first mode of operation and a second mode of operation. For example, when at least one control signal indicates a first mode of operation, a corresponding current regulator or limiter may be configured to disable the current. Conversely, when the at least one control signal indicates the second mode of operation, the corresponding current regulator or limiter may be configured to limit the current to the corresponding maximum value. For example for this purpose, the at least one control signal may comprise a pulse width modulation signal, wherein a first logic level of the pulse width modulation signal indicates a first mode of operation and a second logic level of the pulse width modulation signal indicates a second operating mode. Typically, at least one control signal may also indicate a maximum value. For example, such a control signal may be used to selectively turn the strings on or off and/or perform dimming of the light emitted by the light source.

例如，在这种情况下，控制电路可以被配置成根据控制信号确定是否应当关断所有固态光源串。例如，在PWM信号的情况下，控制电路可以确定控制信号是否指示所有电流调节器或限制器对于完整的PWM周期或对于多个PWM周期被关断(第一操作模式)。在这种情况下，控制电路也可以通过将数字调节值设置成指示所请求的最小输出电压的第二值来(基本)使所述电压源无效。For example, in this case, the control circuit may be configured to determine from the control signal whether all strings of solid state light sources should be turned off. For example, in the case of a PWM signal, the control circuit may determine whether the control signal instructs all current regulators or limiters to be turned off for a full PWM cycle or for multiple PWM cycles (first mode of operation). In this case, the control circuit may also (substantially) deactivate the voltage source by setting the digital adjustment value to a second value indicative of the requested minimum output voltage.

另外，控制电路可以被配置成根据控制信号确定是否应当接通固态光源串中的至少一个固态光源串(第二操作模式)。例如，在PWM信号的情况下，控制电路可以确定控制信号是否指示至少一个电流调节器或限制器应当在当前PWM周期期间被接通。Additionally, the control circuit may be configured to determine from the control signal whether at least one of the strings of solid state light sources should be turned on (second mode of operation). For example, in the case of a PWM signal, the control circuit may determine whether the control signal indicates that at least one current regulator or limiter should be turned on during the current PWM cycle.

具体地，在使输出电压无效的情况下，控制电路可以通过开始新的前馈控制动作来恢复操作。具体地，响应于已经确定至少一个电流调节器或限制器应当被接通，控制电路可以验证数字调节值是否对应于第二(最小)值(指示输出电压具有其最小值)。在这种情况下，控制电路可以将数字调节值设置成第一(最大)值。因此，响应于将数字调节值设置成第一(最大)值，电压源将提供最大输出电压，并且控制电路将再次根据前馈值(在给定时段之后)设置数字调节值。Specifically, in the event of deactivating the output voltage, the control circuit can resume operation by starting a new feedforward control action. Specifically, in response to having determined that at least one current regulator or limiter should be turned on, the control circuit may verify whether the digital regulation value corresponds to the second (minimum) value (indicating that the output voltage has its minimum value). In this case, the control circuit may set the digital adjustment value to the first (maximum) value. Thus, in response to setting the digital adjustment value to the first (maximum) value, the voltage source will provide the maximum output voltage and the control circuit will again set the digital adjustment value according to the feedforward value (after a given period).

在各种实施例中，控制电路也可以确定光源是否确实被供电。例如，为此目的，控制电路可以确定控制信号是否指示至少一个电流调节器或限制器应当使用第二操作模式。在这种情况下，控制电路可以确定电流是否流过应当使用第二操作模式的至少一个电流调节器或限制器。例如，响应于确定没有电流流过应当使用第二操作模式的电流调节器或限制器中的至少一个，控制电路可以改变数字调节值以便增加所请求的输出电压。In various embodiments, the control circuit may also determine whether the light source is indeed powered. For example, for this purpose, the control circuit may determine whether the control signal indicates that the at least one current regulator or limiter should use the second mode of operation. In this case, the control circuit may determine whether current is flowing through the at least one current regulator or limiter that should use the second mode of operation. For example, in response to determining that no current is flowing through at least one of the current regulator or limiter that should use the second mode of operation, the control circuit may change the digital regulation value to increase the requested output voltage.

附图说明Description of drawings

现在将参考附图描述本公开的实施例，附图仅通过非限制性示例的方式提供，并且其中：Embodiments of the present disclosure will now be described with reference to the accompanying drawings, provided by way of non-limiting example only, and in which:

图1示出典型的电源系统；Figure 1 shows a typical power system;

图2和图3示出利用电子转换器实现的电压源的示例；Figures 2 and 3 show examples of voltage sources implemented with electronic converters;

图4A、图4B和图5示出电源系统的示例，其中，电压源和电流供应系统用于向多个固态光源串供电；Figures 4A, 4B and 5 illustrate examples of power supply systems in which a voltage source and current supply system are used to power multiple strings of solid state light sources;

图6和图7示出用于固态光源串的电流供应系统的实施例；6 and 7 illustrate embodiments of current supply systems for strings of solid state light sources;

图8和图9示出用于图6和图7的电流供应系统的控制电路的实施例；Figures 8 and 9 illustrate embodiments of control circuits for the current supply system of Figures 6 and 7;

图10和图11示出图8和图9的控制电路的操作的实施例；Figures 10 and 11 illustrate an embodiment of the operation of the control circuit of Figures 8 and 9;

图12和图13示出实施例，其中，多个电流供应系统连接至同一电压源；以及Figures 12 and 13 illustrate embodiments in which multiple current supply systems are connected to the same voltage source; and

图14示出用于固态光源串的电流供应系统的另外的实施例。Figure 14 shows a further embodiment of a current supply system for a string of solid state light sources.

具体实施方式Detailed ways

在以下描述中，给出了许多具体细节以提供对实施例的透彻理解。可以在没有一个或几个具体细节的情况下，或者利用其他方法、组件、材料等来实施所述实施例。在其他情况下，没有详细示出或描述公知的结构、材料或操作，以避免使实施例的方面模糊。In the following description, numerous specific details are set forth to provide a thorough understanding of the embodiments. The described embodiments may be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations have not been shown or described in detail to avoid obscuring aspects of the embodiments.

在整个说明书中对“一个实施例”或“实施例”的引用意味着结合该实施例描述的特定特征、结构或特性被包括在至少一个实施例中。因此，在本说明书中的各个地方出现的短语“在一个实施例中”或“在实施例中”不一定全部指代同一实施例。此外，特定特征、结构或特性可以以任何合适的方式组合在一个或多个实施例中。Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" in various places in this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments.

本文提供的标题仅为了方便起见并且不解释实施例的范围或含义。The headings provided herein are for convenience only and do not interpret the scope or meaning of the embodiments.

在下面的图6至图14中，将注意到，已经参考图1和图5描述的部件、元件或组件由先前在这些图中使用的相同附图标记表示；为了不使本具体实施方式过于复杂，下面将不再重复对这些前述元件的描述。In Figures 6 to 14 below, it will be noted that parts, elements or assemblies that have been described with reference to Figures 1 and 5 are designated by the same reference numerals previously used in these Figures; in order not to obscure the present detailed description Complicated, the description of these aforementioned elements will not be repeated below.

如前所述，本说明书涉及用于向负载供应电流的解决方案，所述负载诸如是如关于图4A、图4B或图5所描述的固态光源L的串34。As previously mentioned, the present specification relates to a solution for supplying current to a load, such as astring 34 of solid state light sources L as described in relation to FIGS. 4A , 4B or 5 .

图6示出与图4B的描述一致的第一实施例，并且图7示出与图4B的描述一致的第一实施例。FIG. 6 shows a first embodiment consistent with the description of FIG. 4B , and FIG. 7 shows a first embodiment consistent with the description of FIG. 4B .

具体地，图6和图7示出用于固态光源L的多个串34(诸如LED串或OLED串)的电源系统的实施例。In particular, FIGS. 6 and 7 illustrate an embodiment of a power supply system formultiple strings 34 of solid state light sources L, such as LED strings or OLED strings.

具体地，在所考虑的实施例中，电源系统包括可变电压源20，所述可变电压源包括：两个输入端子(例如，关于图1和图2描述的端子200a和200b)被配置成接收输入电压V_in，并且正输出端子202a和负输出端子202b被配置成提供(调节的)输出电压V_out。Specifically, in the embodiment under consideration, the power supply system includes avariable voltage source 20 comprising: two input terminals (eg,terminals 200a and 200b described with respect to FIGS. 1 and 2 ) are configured is configured to receive an input voltage V_in , and thepositive output terminal 202a and thenegative output terminal 202b are configured to provide a (regulated) output voltage V_out .

通常，电压源20可以是线性调节器，或者优选地是如关于图2和图3所描述的开关模式电子转换器。例如，在图6和图7中示意地示出电压源20，该电压源被配置成接收：来自反馈电路24(例如包括至少两个电阻器R1和R2的分压器)的指示输出电压V_out(并且优选地与输出电压成比例)的反馈信号FB；以及指示所请求的输出电压V_out(并且优选与所请求的输出电压成比例)的参考信号V_ref。Typically, thevoltage source 20 may be a linear regulator, or preferably a switch-mode electronic converter as described with respect to FIGS. 2 and 3 . For example, avoltage source 20 is shown schematically in FIGS. 6 and 7 , the voltage source being configured to receive: an indicated output voltage V from a feedback circuit 24 (eg, a voltage divider including at least two resistors R1 and R2 ) A feedback signal FB_out (and preferably proportional to the output voltage); and a reference signal_Vref indicative of the requested output voltage_Vout (and preferably proportional to the requested output voltage).

在各种实施例中，反馈电路24也可以直接集成在电压源20中。In various embodiments, thefeedback circuit 24 may also be directly integrated into thevoltage source 20 .

在所考虑的实施例中，电源系统还包括电流供应系统。具体地，电流供应系统包括：In the considered embodiment, the power supply system further comprises a current supply system. Specifically, the current supply system includes:

一个或多个第一端子，被配置成连接到电压源20的第一输出端子，例如，图6中的负输出端子202b或图7中的正输出端子202a；以及one or more first terminals configured to be connected to a first output terminal of thevoltage source 20, eg, thenegative output terminal 202b in FIG. 6 or thepositive output terminal 202a in FIG. 7; and

给定数量n的第二端子OUT1、...、OUTn(例如端子OUT1、...、OUT4)，其中，每个第二端子OUT被配置成经由相应的固态光源串34连接到电压源20的第二输出端子，例如图6中的正输出端子202a或图7中的负输出端子202b；以及A given number n of second terminals OUT1 , . . . , OUTn (eg, terminals OUT1 , . the second output terminal of , such as thepositive output terminal 202a in FIG. 6 or thenegative output terminal 202b in FIG. 7; and

给定数量N的电流调节器/限制器32，其中，相应的电流调节器/限制器32(例如直接)连接在相应的第二端子OUT和所述一个或多个第一端子中的至少一个第一端子之间。a given number N of current regulators/limiters 32, wherein the respective current regulator/limiter 32 is connected (eg directly) to the respective second terminal OUT and at least one of the one or more first terminals between the first terminals.

具体而言，每个电流调节器/限制器32被配置成将流经电流调节器/限制器32的电流根据相应控制信号CTRL(即信号CTRL1、...、CTRL)限制成相应的最大值，由此每个电流调节器/限制器32被配置成将流经相应固态光源串34的电流限制成相应的最大值。具体地，电流调节器/限制器32在图6中所示的实施例中是电流吸收器，并且在图7中所示的实施例中是电流源。Specifically, each current regulator/limiter 32 is configured to limit the current flowing through the current regulator/limiter 32 to a corresponding maximum value in accordance with the corresponding control signal CTRL (ie, the signals CTRL1, . . . , CTRL). Thus, each current regulator/limiter 32 is configured to limit the current flowing through the corresponding solid statelight source string 34 to a corresponding maximum value. Specifically, the current regulator/limiter 32 is a current sink in the embodiment shown in FIG. 6 and a current source in the embodiment shown in FIG. 7 .

在所考虑的实施例中，电流供应系统还包括用于向电压源20提供参考信号V_ref的另外的端子和控制电路40，控制电路被配置成：生成控制信号CTRL1、...、CTRLn；监控第二端子OUT1、...、OUTn中的每个第二端子处的电压；并且在所述另外的端子处生成参考信号V_ref，从而设置所请求的输出电压V_out。In the considered embodiment, the current supply system further comprises further terminals for supplying the reference signal_Vref to thevoltage source 20 and acontrol circuit 40, the control circuit being configured to: generate the control signals CTRL1, . . . , CTRLn; monitoring the voltage at each of the second terminals OUT1, . . . , OUTn; and generating a reference signal_Vref at the further terminal to set the requested output voltage_Vout .

在各种实施例中，电流供应系统、尤其是电流调节器/限制器32和控制电路40可以在同一集成电路中实现。在各种实施例中，电压源20的控制电路22(参见图2)也可以实现在同一集成电路中。In various embodiments, the current supply system, particularly the current regulator/limiter 32 and thecontrol circuit 40, may be implemented in the same integrated circuit. In various embodiments, the control circuit 22 (see FIG. 2 ) of thevoltage source 20 may also be implemented in the same integrated circuit.

如前所述，在各种实施例中，控制信号CTRL可以是二进制信号，其中，每个电流调节器/限制器32被配置成当信号CTRL具有第一逻辑值时将流经相应串34的电流限制为零，并且当信号CTRL具有第二逻辑值时将流经相应串的电流限制为相应(恒定)最大值。然而，信号CTRL也可以是能够直接设置最大值的模拟信号或者能够设置多个最大值的数字信号。As previously mentioned, in various embodiments, the control signal CTRL may be a binary signal, wherein each current regulator/limiter 32 is configured to flow through the correspondingstring 34 when the signal CTRL has a first logic value. The current limit is zero and the current through the respective string is limited to the respective (constant) maximum value when the signal CTRL has the second logic value. However, the signal CTRL may also be an analog signal capable of directly setting a maximum value or a digital signal capable of setting a plurality of maximum values.

例如，在各种实施例中，控制电路40被配置成生成作为脉宽调制(PWM)信号的信号CTRL，其中，信号具有相同的开关时段，但是每个信号CTRL具有各自的占空比。For example, in various embodiments, thecontrol circuit 40 is configured to generate the signals CTRL as pulse width modulated (PWM) signals, wherein the signals have the same switching period, but each signal CTRL has a respective duty cycle.

在各种实施例中，串34还可以包括不同数量的光源L(参见图4A和图4B的描述)。附加地或替代地，每个光源L也可以具有相关联的相应电子开关，该电子开关被配置成选择性地使光源L短路，从而允许对每个光源的电源的单独控制(参见图5的描述)。In various embodiments,string 34 may also include a different number of light sources L (see description of Figures 4A and 4B). Additionally or alternatively, each light source L may also have an associated respective electronic switch configured to selectively short-circuit the light sources L, thereby allowing individual control of the power supply to each light source (see FIG. 5 ). describe).

因此，每个信号CTRL也可以包括多个模拟信号和/或数字信号，例如用于设置最大值的信号，以及一个或多个PWM信号，用于接通和关断相应的LED串34和/或光源L的或相应的LED串34的子集。Thus, each signal CTRL may also include a plurality of analog and/or digital signals, such as a signal for setting a maximum value, and one or more PWM signals for switching on and off the correspondingLED string 34 and/or or a subset of the light source L or the correspondingLED string 34 .

例如在各种实施例中，控制电路40可以被配置成生成信号CTRL和可选地生成用于附加电子开关Sw的驱动信号Sw_CTRL，以便生成例如有源LED或OLED面板的所请求的照明模式。例如，为此目的，控制电路40可以包括用于接收识别所请求的照明模式的数据的通信接口。For example, in various embodiments, thecontrol circuit 40 may be configured to generate the signal CTRL and optionally the drive signal Sw_CTRL for the additional electronic switch Sw in order to generate the requested lighting mode of eg an active LED or OLED panel. For example, for this purpose, thecontrol circuit 40 may include a communication interface for receiving data identifying the requested lighting pattern.

因此，在各种实施例中，固态光源的被激活的串34的数量可以随时间而改变。此外，在各种实施例中，串34的固态光源的数量可以不同(基于应用)，或者被激活的串34的被激活的固态光源的数量可以随着时间而改变，即，被激活的串34处的电压降可以随着时间而改变。此外，在被激活的串34处的电压降也可能由于其他原因(诸如温度变化)和/或由于流过该串的最大电流的不同设置而改变。Thus, in various embodiments, the number of activatedstrings 34 of solid state light sources may vary over time. Furthermore, in various embodiments, the number of solid state light sources ofstrings 34 may vary (based on the application), or the number of activated solid state light sources ofstrings 34 may vary over time, ie, strings 34 are activated The voltage drop at 34 can vary over time. Furthermore, the voltage drop at the activatedstring 34 may also vary due to other reasons (such as temperature changes) and/or due to different settings of the maximum current flowing through the string.

在各种实施例中，控制电路40被配置成根据端子OUT1、...、OUTn处的电压V_OUT1、...、V_OUTn生成参考信号V_ref。通常，控制电路40可以被配置成测量端子OUT1、...、OUTn处的相对于正端子202a(即V_out)或优选地相对于负端子202b(即接地)的电压V_OUT1、...、V_OUTn。例如，在图6中，控制电路40被配置成测量端子OUT处的相对于一个或多个第一端子(连接到负端子/接地202b)的电压，从而测量相应电流调节器/限制器32处的电压降。相反地，在图7中，控制电路40被配置成测量端子OUT处的相对于负端子/接地202b的电压，从而测量相应固态光源串34处的电压降。In various embodiments, thecontrol circuit 40 is configured to generate the reference signal V_ref from the voltages V_OUT1 , . . . , V_OUTn at the terminals OUT1 , . . . , OUTn. In general, thecontrol circuit 40 may be configured to measure the voltage V_OUT1 , . . . at the terminals_OUT1 , . , V_OUTn . For example, in FIG. 6 , thecontrol circuit 40 is configured to measure the voltage at the terminal OUT relative to the one or more first terminals (connected to the negative terminal/ground 202b ), thereby measuring the voltage at the corresponding current regulator/limiter 32 voltage drop. Conversely, in FIG. 7 , thecontrol circuit 40 is configured to measure the voltage at the terminal OUT relative to the negative terminal/ground 202b , thereby measuring the voltage drop at the corresponding solid statelight source string 34 .

具体地，在各种实施例中，控制电路40被配置成确定串34处的最大电压降V_{LED_MAX}，并且将输出电压V_out(经由参考信号V_ref)设置成大于给定量V_M的值。在各种实施例中，在不中断由串34投射的当前照明模式的情况下执行该动态自适应。例如，这在汽车领域中特别有意义，其中，串34可以用于发信号通知警告情况或危险情况。在各种实施例中，动态自适应还能够调节输出电压，以便使输出电压适应于与OLED、工艺扩展和/或温度特别相关的其他变化，诸如老化现象。Specifically, in various embodiments, thecontrol circuit 40 is configured to determine the maximum voltage drop_{VLED_MAX} at thestring 34 and to set the output voltage_Vout (via the reference signal_Vref ) to a value greater than a given amount_VM . In various embodiments, this dynamic adaptation is performed without interrupting the current lighting pattern projected bystring 34 . This is of particular interest in the automotive field, for example, where thestring 34 can be used to signal a warning situation or a dangerous situation. In various embodiments, dynamic adaptation can also adjust the output voltage in order to adapt the output voltage to other changes particularly related to OLED, process scaling, and/or temperature, such as burn-in phenomena.

在各种实施例中，经由控制电路40内的数字处理来执行以上操作。例如，这具有的优点是，控制电路40也可以执行一系列进一步的诊断和功能操作，诸如：In various embodiments, the above operations are performed via digital processing withincontrol circuit 40 . This has the advantage, for example, that thecontrol circuit 40 can also perform a series of further diagnostic and functional operations such as:

-监控负载条件，例如以便确定临时或永久的开路负载或短路条件，这些负载条件例如可以用于禁用相应的光源串；- monitoring load conditions, eg in order to determine temporary or permanent open-circuit load or short-circuit conditions, which load conditions can eg be used to disable the corresponding light source string;

-监控电流调节器/限制器32和/或串34的一个或多个温度，所述一个或多个温度可以用于禁用相应的电流调节器32和串34，或者减小相应的最大电流；- monitoring one or more temperatures of the current regulator/limiter 32 and/orstring 34, which can be used to disable the correspondingcurrent regulator 32 andstring 34, or reduce the corresponding maximum current;

-实现热降额模型，其中，基于对光源的过高温度的测量来适应最大电流。- Implementing a thermal derating model, wherein the maximum current is adapted based on the measurement of excessive temperature of the light source.

如上所述，通常电流供应系统包括给定数量n的电流调节器/限制器32，所述电流调节器/限制器连接到相应端子OUT1、...、OUTn，其中每个端子OUT1、...、OUTn可以经由相应的固态光源串34连接到电压源20的输出端子。通常，实际连接到n个电流调节器/限制器32的串32的数量也可小于n。此外，每个电流调节器/限制器32可以总是被使能，或优选地经由相应的控制信号CTRL1、...、CTRLn选择性地使能，即，有源串34的数量可以是固定的或可变的。As mentioned above, typically the current supply system comprises a given number n of current regulators/limiters 32 connected to respective terminals OUT1, .., OUTn, wherein each terminal OUT1, .. ., OUTn may be connected to the output terminals of thevoltage source 20 via therespective strings 34 of solid state light sources. Typically, the number ofstrings 32 actually connected to n current regulators/limiters 32 may also be less than n. Furthermore, each current regulator/limiter 32 may always be enabled, or preferably selectively enabled via respective control signals CTRL1, . . . , CTRLn, ie the number ofactive strings 34 may be fixed , or variable.

在各种实施例中，控制电路40被配置成：例如，根据该控制信号CTRL1、...、CTRLn来确定该固态光源的被激活的串34；并且确定指示在固态光源的被激活的串34处的最大电压降(并且优选地与该最大电压降成比例)的数字样本。In various embodiments, thecontrol circuit 40 is configured to: determine the activatedstring 34 of the solid state light source, eg, from the control signals CTRL1, . . . , CTRLn; and to determine the activated string indicating the solid state light source at Digital samples of the maximum voltage drop at 34 (and preferably proportional to this maximum voltage drop).

如前所述，控制电路40可以被配置成直接监控固态光源串34处的电压降。在这方面，最大电压降的选择可以在模拟电平(即，在模数转换之前)或在数字电平(即，在模数转换之后)执行。As previously discussed, thecontrol circuit 40 may be configured to directly monitor the voltage drop at the string of solid statelight sources 34 . In this regard, the selection of the maximum voltage drop may be performed at the analog level (ie, before the analog-to-digital conversion) or at the digital level (ie, after the analog-to-digital conversion).

可替代地，控制电路40可以被配置成监控电流调节器/限制器32处的电压降。在这种情况下，控制电路40可以根据电流调节器/限制器32处的电压降和电压V_out计算固态光源串34处的电压降。同样在这种情况下，可以在模拟电平(即，在模数转换之前)执行一个或多个先前操作，或者可以在数字电平(即，在模数转换之后)执行所有操作。Alternatively, thecontrol circuit 40 may be configured to monitor the voltage drop at the current regulator/limiter 32 . In this case, thecontrol circuit 40 may calculate the voltage drop at the solid statelight source string 34 from the voltage drop at the current regulator/limiter 32 and the voltage V_out . Also in this case, one or more of the previous operations may be performed at the analog level (ie, before the analog-to-digital conversion), or all operations may be performed at the digital level (ie, after the analog-to-digital conversion).

例如，图8示出控制电路40的实施例，其中控制电路40被配置成例如通过在图6中测量端子OUT处相对于端子202b/接地的电压来监控指示电流调节器/限制器32处的电压降(并且优选地与该电压降成比例)的电压。For example, FIG. 8 shows an embodiment of acontrol circuit 40 that is configured to monitor the indicated current regulator/limiter 32 for example by measuring the voltage at terminal OUT relative to terminal 202b/ground in FIG. 6 . The voltage at which the voltage drops (and preferably is proportional to the voltage drop).

例如，在所考虑的实施例中，控制电路40被配置成获取端子OUT1、...、OUTn处的电压V_OUT1、...、V_OUTn的数字样本V_{OUT1_ADC}、...、V_{OUTn_ADC}，并且将这些数字样本V_{OUT1_ADC}、...、V_{OUTn_ADC}存储到存储器406。例如，如图8示意所示，为此目的，控制电路可以包括至少一个模数转换器(ADC)404以及被配置成将一个或多个模数转换器404连接到端子OUT1、...、OUTn的可选的多路复用器402。通常，多路复用器402完全是可选的，因为控制电路50也可以包括n个ADC404，即每个端子OUT1、...、OUTn一个ADC。例如，在各种实施例中，(一个或多个)ADC404具有8、12或16比特的分辨率。For example, in the embodiment under consideration, thecontrol circuit 40 is configured to obtain digital samples V_{OUT1_ADC} , . . . , V_{OUTn_ADC} of the voltages V_OUT1 , . . . , V_OUTn at the terminals OUT1 , . And these digital samples V_{OUT1_ADC} , . . . , V_{OUTn_ADC} are stored tomemory 406 . For example, as schematically shown in FIG. 8, for this purpose, the control circuit may comprise at least one analog-to-digital converter (ADC) 404 and be configured to connect the one or more analog-to-digital converters 404 to the terminals OUT1, . . . ,Optional multiplexer 402 for OUTn. In general, themultiplexer 402 is entirely optional, as the control circuit 50 may also includen ADCs 404, ie one ADC per terminal OUT1, . . . , OUTn. For example, in various embodiments, ADC(s) 404 have a resolution of 8, 12, or 16 bits.

通常，(一个或多个)ADC的数量和相应的转换速度应当被选择以便确保可以以足够高的频率对电压V_OUT1、...、V_OUTn进行采样。In general, the number of ADC(s) and the corresponding conversion speed should be chosen to ensure that the voltages V_OUT1 , . . . , V_OUTn can be sampled at a sufficiently high frequency.

例如，如前所述，信号CTRL可以是PWM信号，其中，每个信号CTRL1、...、CTRLn对于给定的接通期间(相应的串被激活)被设置成高电平，并且对于给定的关断持续时间(相应的串被解除激活)被设置成低电平。通常，信号CTRL1、...、CTRLn也可以在完整的PWM周期期间保持低电平，由此解除激活相应的串，即，占空比可以在[0；1]的范围中被选择。For example, as before, the signal CTRL may be a PWM signal, wherein each signal CTRL1, . . . , CTRLn is set high for a given on-period (the corresponding string is activated), and is set low for a given off-time duration (the corresponding string is deactivated). Typically, the signals CTRL1, . . . , CTRLn can also remain low during a complete PWM cycle, thereby deactivating the corresponding string, ie the duty cycle can be selected in the range [0;1].

因此，该控制电路40可以被配置成获得各电压V_OUT1、...、V_OUTn的一个或多个数字样本，而相应的信号CTRL1、...、CTRLn被设置成高电平。例如，通常这种PWM信号具有200和1400Hz之间的频率。因此，如果PWM信号的最小接通时间大于ADC转换时间加上用于对所有信道进行采样的多路复用时间，则可以使用单个ADC 404。Thus, thecontrol circuit 40 may be configured to obtain one or more digital samples of each of the voltages V_OUT1 , . . . , V_OUTn , with the corresponding signals CTRL1 , . For example, typically such a PWM signal has a frequency between 200 and 1400 Hz. Therefore, asingle ADC 404 can be used if the minimum on-time of the PWM signal is greater than the ADC conversion time plus the multiplexing time for sampling all channels.

在不同的实施例中，该控制电路40也可以在不同的信号CTRL1、...、CTRL之间引入相位偏移，相位偏移允许取样不同的电压序列。在各种实施例中，该控制电路也可以被配置成：对于在给定PWM周期期间待被激活的串34，确保接通时间大于允许经由(一个或多个)ADC 404进行采样的给定最小值。In different embodiments, thecontrol circuit 40 may also introduce phase offsets between the different signals CTRL1, . . . , CTRL, which allow different voltage sequences to be sampled. In various embodiments, the control circuit may also be configured to ensure that the on-time is greater than a given allowable sampling via the ADC(s) 404 for thestring 34 to be activated during a given PWM period minimum value.

因此，在所考虑的实施例中，样本V_{OUT1_ADC}、...、V_{OUTn_ADC}指示电流调节器/限制器32处的电压降。Thus, in the considered embodiment, the samples V_{OUT1_ADC} , . . . , V_{OUTn_ADC are} indicative of the voltage drop at the current regulator/limiter 32 .

在所考虑的实施例中，控制电路40因此也被配置成(经由一个或多个ADC 404和可选的多路复用器402)获取端子202a处的电压V_out的数字样本V_{out_ADC}，并且将样本V_{out_ADC}存储到存储器406。In the embodiment under consideration, thecontrol circuit 40 is thus also configured (via one or more ADCs 404 and optional multiplexer 402) to obtain digital samples_{Vout_ADC} of the voltage_Vout at terminal 202a, and The samples V_{out_ADC} are stored tomemory 406 .

具体地，在各种实施例中，控制电路40被配置成根据数字样本V_{OUT1_ADC}、…、V_{OUTn_ADC}及该数字样本V_{out_ADC}确定被激活的串32(例如，在该当前PWM周期期间相应的信号CTRL1、…、CTRLn已被设置成高电平的串34)处的最大电压降V_{LED_MAX}。Specifically, in various embodiments, thecontrol circuit 40 is configured to determine the activated string 32 (eg, the corresponding signal during the current PWM cycle) from the digital samples V_{OUT1_ADC} , . . . , V_{OUTn_ADC} and the digital samples V_{out_ADC} Maximum voltage drop_{VLED_MAX} at string 34) where CTRL1,...,CTRLn have been set high.

例如，在所考虑的实施例中，控制电路40首先在模块/电路408处选择数字样本V_{OUT1_ADC}、…、V_{OUTn_ADC}的最小值V_{OUT_MIN}、即电流调节器/限制器32处的最小电压降，并且然后在模块/电路410处根据以下公式计算最大电压降V_{LED_MAX}：For example, in the embodiment under consideration,control circuit 40 first selects at module/circuit 408 the minimum value V_{OUT_MIN} of digital samples V_{OUT1_ADC} , . . . , V_{OUTn_ADC} , ie, the minimum voltage drop at current regulator/limiter 32 , And then the maximum voltage drop_{VLED_MAX} is calculated at module/circuit 410 according to the following formula:

V_{LED_MAX}＝V_{out_ADC}-V_{OUT_MIN}。 (1)V_{LED_MAX} =V_{out_ADC} -V_{OUT_MIN} . (1)

相反，图9示出实施例，其中，控制电路40被配置成例如通过在图7中测量端子OUT1、…、OUTn处相对于端子202b/接地的电压来直接监控指示串24处的电压降(并且优选地与该电压降成比例)的电压。In contrast, FIG. 9 shows an embodiment in which thecontrol circuit 40 is configured to directly monitor the voltage drop at the indicator string 24 (eg by measuring the voltage at the terminals OUT1 , . . . , OUTn relative to terminal 202b/ground in FIG. 7 ) and preferably proportional to this voltage drop).

因此，在这种情况下，存储到存储器404的样本V_{OUT1_ADC}、…、V_{OUTn_ADC}已经指示串34处的电压降，并且控制电路40被配置成通过在块/电路416处选择数字样本V_{OUT1_ADC}、…、V_{OUTn_ADC}的最大值来确定最大电压降V_{LED_MAX}。Thus, in this case, the samples V_{OUT1_ADC} , . . . , V_{OUTn_ADC} stored tomemory 404 have indicated the voltage drop atstring 34 , andcontrol circuit 40 is configured to select digital samples V_{OUT1_ADC} , V OUTn_ADC at block/circuit 416 , ..., the maximum value of V_{OUTn_ADC} to determine the maximum voltage drop V_{LED_MAX} .

通常，如前所述，在块408或块416的选择应当仅使用与激活的电流调节器/限制器34相关联的样本V_{OUT1_ADC}、…、V_{OUTn_ADC}。这可以在AD转换期间已经实现(即，通过仅对激活的电流调节器/限制器的值进行采样)和/或通过在块408或416处根据控制信号CTRL选择样本的子集来实现。Typically, the selection atblock 408 or block 416 should use only the samples V_{OUT1_ADC} , . . . , V_{OUTn_ADC} associated with active current regulator/limiter 34 , as previously described. This may already be accomplished during AD conversion (ie, by sampling only the value of the active current regulator/limiter) and/or by selecting a subset of the samples atblock 408 or 416 according to the control signal CTRL.

因此，在图8和图9所示的实施例中，控制电路40被配置成获得端子OUT1、...、OUTn处的电压的数字样本，并且确定串34处的最大电压降V_{LED_MAX}。如前所述，这也可以包括测量输出电压V_out，如图8所示。Thus, in the embodiment shown in FIGS. 8 and 9 , thecontrol circuit 40 is configured to obtain digital samples of the voltages at the terminals OUT1 , . . . , OUTn and to determine the maximum voltage drop V_{LED — MAX} at thestring 34 . As previously mentioned, this can also include measuring the output voltage V_out , as shown in FIG. 8 .

一旦获得最大电压降V_{LED_MAX}，控制电路就可以通过将给定的裕量电压V_M加到最大电压降V_{LED_MAX}来确定所请求的输出电压V_{out_req}，即：Once the maximum voltage drop_{VLED_MAX} is obtained, the control circuit can determine the requested output voltage_{Vout_req} by adding the given headroom voltage_VM to the maximum voltage drop_{VLED_MAX} , namely:

V_{out_req}＝V_{LED_MAX}+V_M。 (2)V_{out_req} =V_{LED_MAX+} VM . (2)

例如，对于典型的电流调节器/限制器，0.5V至1.5V的裕量电压，例如在0.5V和1.0V之间，是足够的。For example, for a typical current regulator/limiter, a headroom voltage of 0.5V to 1.5V, eg between 0.5V and 1.0V, is sufficient.

例如，图8和图9示意地示出加法器块/电路412，加法器块/电路被配置成通过将数字值V_M加到数字值V_{LED_MAX}来生成数字信号V_{out_req}。For example, FIGS. 8 and 9 schematically illustrate an adder block/circuit 412 configured to generate a digital signal_{Vout_req} by adding a digital value VM to a digital_{value VLED_MAX.}

此外，控制电路40被配置成根据所请求的输出电压V_{out_req}确定参考信号V_ref的值。具体地，如前所述，在各个实施例中，反馈信号FB与输出电压成比例，并且电压源20被配置成将反馈信号FB调节为参考信号V_ref，即，输出电压可以计算如下：Furthermore, thecontrol circuit 40 is configured to determine the value of the reference signal_Vref according to the requested output voltage_{Vout_req} . Specifically, as previously described, in various embodiments, the feedback signal FB is proportional to the output voltage, and thevoltage source 20 is configured to adjust the feedback signal FB to the reference signal V_ref , ie, the output voltage can be calculated as follows:

例如，通过使用如图6和图7所示的分压器，输出电压可以计算如下：For example, by using the voltage divider shown in Figure 6 and Figure 7, the output voltage can be calculated as follows:

因此，通过重新表述公式(2)和(3)，参考信号V_ref的值可以计算为：Therefore, by restating equations (2) and (3), the value of the reference signal_Vref can be calculated as:

V_ref＝K·(V_{LED_MAX}+V_M)。 (5)V_ref =K·(V_{LED_MAX+} VM ). (5)

例如，在各种实施例中，比例值K可以在控制电路40中固定，并且反馈电路24应当被配置成使用相同的比例值K。可替代地，值K可以是可编程的。For example, in various embodiments, the scale value K may be fixed in thecontrol circuit 40 and thefeedback circuit 24 should be configured to use the same scale value K. Alternatively, the value K may be programmable.

例如，图8和图9示出数模转换器(DAC)418以及块/电路414，数模转换器被配置成根据数字信号V_reg生成参考信号V_ref，块/电路被配置成例如通过根据系数缩放信号V_{out_req}来根据数字信号V_{out_req}生成V_reg。实际上，电路414可以被配置成使用比例值，该比例值还考虑了DAC 418的转换率，以便获得如公式(5)所示的所请求的参考信号V_ref。For example, FIGS. 8 and 9 show a digital-to-analog converter (DAC) 418 configured to generate a reference signal_Vref from a digital signal_Vreg and a block/circuit 414 configured to, for example, by The coefficients scale the signal V_{out_req} to generate V_reg from the digital signal V_{out_req} . In practice,circuit 414 may be configured to use a scaling value that also takes into account the slew rate ofDAC 418 in order to obtain the requested reference signal_Vref as shown in equation (5).

因此，在各种实施例中，输出电压V_out被设置成在给定PWM周期期间被激活的所述串34处的最大电压降V_{LED_MAX}加上附加的裕量电压V_M，从而在所有操作条件下自动优化所供应的功率。Thus, in various embodiments, the output voltage_Vout is set to the maximum voltage drop_{VLED_MAX} at thestring 34 that is activated during a given PWM period plus an additional headroom voltage_VM , so that at all operations The supplied power is automatically optimized under the conditions.

然而，在下一个PWM时段期间激活附加串34的情况下，该串34可以具有大于或小于先前最大电压降的电压降。例如，在电压降较大的情况下，输出电压V_out可能太小而不能为该串34的光源供电，由此相应的光源不被接通，从而导致开路负载条件。However, where anadditional string 34 is activated during the next PWM period, thatstring 34 may have a voltage drop that is greater or less than the previous maximum voltage drop. For example, in the case of a large voltage drop, the output voltage_Vout may be too small to power the light sources of thestring 34, whereby the corresponding light sources are not turned on, resulting in an open load condition.

在各种实施例中，控制电路40被配置成例如基于相应的电压V_{OUT1_ADC}、...、V_{OUTn_ADC}的值或通过使用附加的电流传感器来确定这样的开路负载条件，并且然后将值V_ref设置为给定的最大值V_{ref_MAX}。In various embodiments, thecontrol circuit 40 is configured to determine such an open load condition, eg, based on the value of the corresponding voltage V_{OUT1_ADC} , . . . , V_{OUTn_ADC} or by using an additional current sensor, and then convert the value V_ref Set to the given maximum value_{Vref_MAX} .

附加地或可替代地，控制电路40可以被配置成：当激活串34时，存储相应的值V_{OUT1_ADC}、...、V_{OUTn_ADC}；当串34是被解除激活的串34时，保持存储的相应值V_{OUT1_ADC}、...、V_{OUTn_ADC}；并且一旦在随后的PWM周期期间激活新的串34，则使用存储的值以便确定存储的值是否大于先前的最大值V_{LED_MAX}；并且在存储的值更大的情况下，将值V_ref设置为给定的最大值V_{ref_MAX}。Additionally or alternatively, thecontrol circuit 40 may be configured to: when thestring 34 is activated, store the corresponding values V_{OUT1_ADC} ,_. the corresponding values V_{OUT1_ADC} , . . . , V_{OUTn_ADC} ; and once thenew string 34 is activated during a subsequent PWM cycle, the stored value is used in order to determine whether the stored value is greater than the previous maximum value V_{LED_MAX} ; For larger cases, set the value_Vref to the given maximum value_{Vref_MAX} .

因此，在具有超过先前计算的最大值V_{LED_MAX}的电压降的串34被使能的情况下，控制电路40可以立即将输出DAC 414的值设置为最大值。Thus, in the event that astring 34 having a voltage drop that exceeds the previously calculated maximum value_{VLED_MAX} is enabled, thecontrol circuit 40 can immediately set the value of theoutput DAC 414 to the maximum value.

因此，在迄今为止所考虑的实施例中，使用了参考信号V_ref的开环/前馈控制。实际上，系数K的值是固定的，或者例如在块414中设置在控制电路40内，而反馈电路应当被配置成例如经由比率R1/R2使用相同的系数K。因此，在串34处的最大电压降V_{LED_MAX}显著变化的情况下，这种类型的控制尤其有用。Therefore, in the embodiments considered so far, open loop/feedforward control of the reference signal_Vref is used. In practice, the value of the coefficient K is fixed or set within thecontrol circuit 40, eg, inblock 414, while the feedback circuit should be configured to use the same coefficient K, eg, via the ratio R1/R2. Therefore, this type of control is particularly useful where the maximum voltage drop_{VLED_MAX} atstring 34 varies significantly.

然而，由于组件的扩展或温度变化而引起的常数K和反馈电路24的相应反馈比(例如，比率R1/R2)的微弱变化可能使调节电压V_out达到比预期更高或更低的值，结果是在电流调节器/限制器32处的应当对应于电压V_M的最小电压降V_{32_MIN}增加或减小，从而在一种情况下在增加的功率消耗方面或者在另外的情况下不允许正确的电流供应方面影响系统的优化。However, slight changes in the constant K and the corresponding feedback ratio of the feedback circuit 24 (eg, the ratio R1/R2) due to component expansion or temperature changes may cause the regulation voltage_Vout to reach a higher or lower value than expected, The result is an increase or decrease in the minimum voltage drop V_{32_MIN} at the current regulator/limiter 32 that should correspond to the voltage_VM , thereby not allowing correctness in terms of increased power consumption in one case or in another case The current supply aspect affects the optimization of the system.

因此，在各种实施例中，当系统接通时(例如，通过暂时接通所有串34)，并且可选地当在随后的PWM周期期间一个或多个串34不再被激活时和/或当在随后的PWM周期期间一个或多个附加串34被重新激活时，使用先前的前馈控制来设置参考信号V_ref。通常，如将在下面更详细地描述的，前馈控制也可以响应于检测到其他事件而被使用。Thus, in various embodiments, when the system is turned on (eg, by temporarily turning on all strings 34), and optionally when one ormore strings 34 are no longer activated during subsequent PWM cycles and/or Or when one or moreadditional strings 34 are reactivated during a subsequent PWM cycle, the previous feedforward control is used to set the reference signal_Vref . In general, feedforward control may also be used in response to detection of other events, as will be described in more detail below.

相反，附加的闭环控制被用于调节参考信号V_ref，以便将电流调节器/限制器32处的最小电压降V_{32_MIN}调节到值V_M(也参见公式(5))。Instead, additional closed-loop control is used to adjust the reference signal_Vref in order to adjust the minimum voltage drop_{V32_MIN} at the current regulator/limiter 32 to the value VM₍ see also equation (5)).

例如，如图8和图9中示意地示出的，该附加闭环调节可以在块/电路414中实现，该块/电路也可以接收最小电压降V_{32_MIN}和值V_M。For example, as shown schematically in Figures 8 and 9, this additional closed loop regulation may be implemented in block/circuit 414, which may also receive the minimum voltage drop_{V32_MIN} and the value VM_.

通常，控制电路40，例如经由(一个或多个)ADC 406和块408/416，可以被配置成通过直接测量电流调节器/限制器32处的电压降V₃₂(参见图8)或通过计算当前输出电压V_{out_ADC}与最大电压V_{LED_MAX}(在图9中测量)之间的差来确定最小电压降V_{32_MIN}。In general, thecontrol circuit 40, eg, via the ADC(s) 406 and blocks 408/416, may be configured either by directly measuring the voltage drop V32 at the current regulator/limiter₃₂ (see FIG. 8) or by calculating The difference between the current output voltage_{Vout_ADC} and the maximum voltage_{VLED_MAX} (measured in Figure 9) determines the minimum voltage drop_{V32_MIN} .

例如，在各种实施例中，控制电路40、例如块/电路414，可以被配置成实现包括集成组件的(数字)调节器，其中，控制电路40被配置成改变(增加或减少)被提供给DAC 418的数字信号V_reg，直到最小电压降V_{32_MIN}对应于电压V_M。For example, in various embodiments,control circuit 40, such as block/circuit 414, may be configured to implement a (digital) regulator comprising integrated components, whereincontrol circuit 40 is configured to vary (increase or decrease) provided The digital signal V_reg to theDAC 418 up to the minimum voltage drop V_{32_MIN} corresponds to the voltage VM_.

相反地，在各种实施例中，控制电路40被配置成使用近似调节，其中，数字信号V_reg的值基于表而变化，该表已经为最小电压降V_{32_MIN}的多个范围存储了值V_reg的相应变化。例如，在各种实施例中，块/电路414使用信号V_reg的以下变化，其中，值OL_THR表示较低的阈值，例如，指示开路负载条件的阈值，例如0.5V：Rather, in various embodiments, thecontrol circuit 40 is configured to use approximate regulation, wherein the value of the digital signal V_reg is varied based on a table that has stored the value V for various ranges of the minimum voltage drop V_{32_MIN} Corresponding changes in_reg . For example, in various embodiments, block/circuit 414 uses the following variation of signal_Vreg , where the value OL_THR represents a lower threshold, eg, a threshold indicative of an open load condition, eg, 0.5V:

V_{32_MIN}V_{32_MIN}V_regV_reg<OL_THR<OL_THR+16+16[OL_THR；0.71V][OL_THR; 0.71V]+4+4[0.71V；1.03V][0.71V; 1.03V]+1+1[1.03V；1.19V][1.03V; 1.19V]00[1.19V；1.51V][1.19V; 1.51V]-1-1[1.51V；1.91V][1.51V; 1.91V]-4-4>1.91V>1.91V-8-8

因此，在这种情况下，电压V_{32_MIN}被调节到在[1.03V；1.19V]的范围中的值。代替存储最小电压降V_{32_MIN}的值，该表还可存储最小电压降V_{32_MIN}与电压V_M之间的差的范围。Therefore, in this case, the voltage V_{32_MIN} is adjusted to a value in the range of [1.03V; 1.19V]. Instead of storing the value of the minimum voltage drop_{V32_MIN} , the table may also store the range of the difference between the minimum voltage drop_{V32_MIN} and the voltage VM_.

另外的示范性调节可以使用信号V_reg的以下变化：Additional exemplary adjustments may use the following changes in signal_Vreg :

V_{32_MIN}V_{32_MIN}V_regV_reg<OL_THR<OL_THR+12+12[OL_THR；0.63V][OL_THR; 0.63V]+4+4[0.63V；1.25V][0.63V; 1.25V]+1+1[1.25V；1.57V][1.25V; 1.57V]00[1.57V；1.88V][1.57V; 1.88V]-1-1[1.88V；2.20V][1.88V; 2.20V]-4-4>2.20V>2.20V-4-4

因此，在这种情况下，电压V_{32_MIN}被调节到在[1.25V；1.57V]的范围中的值。Therefore, in this case, the voltage V_{32_MIN} is adjusted to a value in the range of [1.25V; 1.57V].

因此，即使参考电压V_ref与输出电压V_out之间的比率不是精确地等于1/K，控制电路40也能够以非常少的步骤校正最小电压降V_{32_MIN}，尤其是直到V_{32_MIN}＝V_M。Therefore, even if the ratio between the reference voltage V_ref and the output voltage V_out is not exactly equal to 1/K, thecontrol circuit 40 can correct the minimum voltage drop V_{32_MIN} in very few steps, especially until V_{32_MIN=} VM .

例如，一旦在给定PWM周期中设置了参考信号V_reg，控制块就可以在随后的PWM周期期间使用闭环控制，以便进一步调节最小电压降V_{32_MIN}。通常，基于电压源20的调节速度，控制电路40可以在每个PWM周期或在给定数量的PWM周期之后改变参考信号V_reg。For example, once the reference signal V_reg is set in a given PWM cycle, the control block can use closed-loop control during subsequent PWM cycles to further adjust the minimum voltage drop V_{32 —MIN} . Generally, based on the speed of regulation of thevoltage source 20, thecontrol circuit 40 may vary the reference signal V_reg every PWM cycle or after a given number of PWM cycles.

图10示出控制电路40的操作的实施例的流程图。FIG. 10 shows a flowchart of an embodiment of the operation of thecontrol circuit 40 .

具体地，在开始步骤1000之后，控制电路40在步骤1002将值V_reg设置为给定的最大值MAX，例如255，由此电压源20提供最大输出电压V_max。接下来，控制电路40前进到步骤1004，其中控制电路40通过(一个或多个)ADC 404获取在端子OUT1、...、OUTn处的电压V_{OUT1_ADC}、...、V_{OUTn_ADC}的样本。在步骤1006，控制电路40然后计算所请求的数字信号V_{out_req}，例如，如上所述(经由图8中的块406、408和410，或者图9中的块406和416)。Specifically, after startingstep 1000, thecontrol circuit 40 sets the value V_reg to a given maximum value MAX, eg, 255, atstep 1002, whereby thevoltage source 20 provides the maximum output voltage V_max . Next, thecontrol circuit 40 proceeds to step 1004 where thecontrol circuit 40 obtains samples of the voltages V_{OUT1_ADC} , . . . , V_{OUTn_ADC} at the terminals OUT1 , . . . , OUTn through the ADC(s) 404 . Atstep 1006, thecontrol circuit 40 then calculates the requested digital signal_{Vout_req} , eg, as described above (viablocks 406, 408 and 410 in FIG. 8, or blocks 406 and 416 in FIG. 9).

在各种实施例中，控制电路40然后进行到可选的异常处理例程1008，异常处理例程可以分析以下各项中的至少一项：数字样本V_{OUT1_ADC}、...、V_{OUTn_ADC}、串34处的最大电压降V_{LED_MAX}和/或调节器34处的最小电压降V_{32_MIN}；以及控制信号CTRL1、...、CTRLn。In various embodiments,control circuitry 40 then proceeds to an optional exception handling routine 1008, which may analyze at least one of the following: digital samples V_{OUT1_ADC} , . . . , V_{OUTn_ADC} , strings the maximum voltage drop_{VLED_MAX} at 34 and/or the minimum voltage drop_{V32_MIN} atregulator 34; and the control signals CTRL1, . . . , CTRLn.

在检测到异常的情况下(步骤1008的输出“Y”)，控制电路进行到步骤1020，其中将值V_reg设置为给定值，这可以取决于检测到的异常。相反，在没有检测到异常的情况下(步骤1008的输出“N”)，控制电路进行到可选步骤1022，其中控制电路40可以确定值V_reg是否大于给定的最小值MIN。In the event an abnormality is detected ("Y" output of step 1008), the control circuit proceeds to step 1020, where the value_Vreg is set to a given value, which may depend on the detected abnormality. Conversely, in the event that no abnormality is detected ("N" output of step 1008), the control circuit proceeds tooptional step 1022, where thecontrol circuit 40 may determine whether the value_Vreg is greater than a given minimum value MIN.

在值V_reg对应于(或小于)最小值MIN(步骤1022的输出“Y”)的情况下，控制电路40在步骤1024处将值V_reg设置为最大值MAX。相反，值V_reg大于最小值MIN(步骤1008的输出“N”)，控制电路进行到步骤1022。如下面将更详细描述的，当所有LED串32被解除激活时，值V_reg可以被设置为最小值MIN。因此，当至少一个LED串32应当被重新激活时，步骤1022和1024用于重新激活电压源20。In the event that the value V_reg corresponds to (or is less than) the minimum value MIN (output "Y" of step 1022 ), thecontrol circuit 40 sets the value V_reg to the maximum value MAX atstep 1024 . Conversely, if the value V_reg is greater than the minimum value MIN (output "N" of step 1008 ), the control circuit proceeds to step 1022 . As will be described in more detail below, when allLED strings 32 are deactivated, the value V_reg may be set to a minimum value MIN. Therefore, steps 1022 and 1024 are used to reactivate thevoltage source 20 when at least oneLED string 32 should be reactivated.

在所考虑的实施例中，控制电路40在步骤1026确定值V_reg是否对应于最大值MAX。在值V_reg对应于(或大于)最大值MAX(步骤1022的输出“Y”)的情况下，控制电路40在步骤1028将值V_reg设置为所请求的数字信号V_{out_req}，从而实现前馈控制。因此，在步骤1028处的前馈控制在启动之后开始(因为在步骤1002将该值设置为MAX)，或者可以通过响应于在步骤1008处检测到的异常在1020将值V_reg设置为MAX来选择性地开始。In the embodiment under consideration, thecontrol circuit 40 determines atstep 1026 whether the value V_reg corresponds to the maximum value MAX. In the event that the value V_reg corresponds to (or is greater than) the maximum value MAX (output "Y" of step 1022 ), thecontrol circuit 40 sets the value V_reg to the requested digital signal V_{out_req} atstep 1028 , thereby implementing feedforward control. Therefore, the feedforward control atstep 1028 starts after startup (since the value is set to MAX at step 1002), or can be set at 1020 by setting the value_Vreg to MAX in response to the anomaly detected atstep 1008 Start selectively.

相反，值V_reg不对应于(或小于)最大值MAX(步骤1026的输出“N”)，控制电路进行到步骤1030，其中开环控制用于根据最小电压降V_{32_MIN}改变值V_reg。Conversely, the value_Vreg does not correspond to (or is less than) the maximum value MAX (output "N" of step 1026), and the control circuit proceeds to step 1030, where open loop control is used to vary the value_Vreg according to the minimum voltage drop_{V32_MIN} .

因此，一旦在步骤1020、1024、1028或1030中的一个步骤处设置了值V_reg，控制电路40可以进行到等待步骤1036，该等待步骤用于设置值V_reg的更新间隔，并且控制电路可以返回到步骤1004以开始新的周期。Thus, once the value_Vreg is set at one ofsteps 1020, 1024, 1028 or 1030, thecontrol circuit 40 may proceed to await step 1036 for setting the update interval of the value_Vreg , and the control circuit may Return to step 1004 to start a new cycle.

因此，在所考虑的实施例中，步骤1008和1036可以在电路或模块414内实现。Accordingly, steps 1008 and 1036 may be implemented within circuit ormodule 414 in the embodiment under consideration.

如前所述，控制电路可以处理各种异常。As mentioned earlier, the control circuit can handle various exceptions.

图11在这方面示出异常处理例程1008的实施例。FIG. 11 illustrates an embodiment of an exception handling routine 1008 in this regard.

具体地，在所考虑的实施例中，异常处理例程可以被配置成验证以下条件中的一个或多个条件：Specifically, in the embodiments under consideration, the exception handling routine may be configured to verify one or more of the following conditions:

-在步骤1010，例如，根据可编程标志，验证是否启用或禁用输出电压V_out的自动适应；- atstep 1010, verify whether the automatic adaptation of the output voltage_Vout is enabled or disabled, eg according to a programmable flag;

-在步骤1012，例如，根据控制信号CTRL1、...、CTRL，验证是否所有LED串34被解除激活(例如，在当前PWM周期期间)；- atstep 1012, for example, based on the control signals CTRL1, .

-在步骤1014，例如，根据控制信号CTRL1、...、CTRL，验证在该系统通电后是否第一次激活给定的LED串；- atstep 1014, for example, according to the control signals CTRL1, .

-在步骤1016，例如，根据值V_{OUT1_ADC}、…、V_{OUTn_ADC}和控制信号CTRL1、…、CTRLn，例如通过验证电压V_{OUT1_ADC}、…、V_{OUTn_ADC}中的一个电压是否指示相应串32的光源L被关断(即使相应控制信号CTRL1、…、CTRLn指示LED串被激活)，来验证是否存在临时开路负载条件；- at step 1016, for example, according to the values V_{OUT1_ADC} , . . . , V_{OUTn_ADC} and the control signals CTRL1_,. off (even if the corresponding control signals CTRL1,...,CTRLn indicate that the LED string is activated), to verify whether there is a temporary open load condition;

-在步骤1018，例如根据控制信号CTRL1、...、CTRLN，验证是否控制信号CTRL1、...、CTRLN中的至少一个控制信号具有不允许经由(一个或多个)ADC 404进行采样的接通持续时间；- atstep 1018, it is verified whether at least one of the control signals CTRL1 , . pass duration;

在各种实施例中，如图11所示，这些步骤可以按顺序布置，例如从步骤1010到1018，从而允许利用优先级(例如，步骤1010的最高优先级到步骤1018的最低优先级)来处理各种异常。In various embodiments, as shown in FIG. 11 , the steps may be arranged in order, eg, fromsteps 1010 to 1018 , thereby allowing the use of priorities (eg, the highest priority ofstep 1010 to the lowest priority of step 1018 ) to Handle various exceptions.

因此，如前所述，可以基于检测到的异常来设置值V_reg。Therefore, as previously described, the value V_reg may be set based on the detected anomaly.

例如，在各种实施例中，控制电路40可以被配置成实现以下操作中的一个或多个操作：For example, in various embodiments,control circuit 40 may be configured to perform one or more of the following operations:

-响应于在步骤1010检测到输出电压V_out的自动适应被禁用，在步骤1020a将值V_reg设置为最大值MAX；- in response to detecting atstep 1010 that the automatic adaptation of the output voltage_Vout is disabled, setting the value_Vreg to the maximum value MAX atstep 1020a;

-响应于在步骤1012检测到所有LED串34被解除激活，在步骤1020b将值V_reg设置为最小值MIN；- in response to detecting atstep 1012 that allLED strings 34 are deactivated, setting the value_Vreg to the minimum value MIN at step 1020b;

-响应于在所述系统通电之后在步骤1014检测到给定LED串被第一次激活，在步骤1020c将值V_reg设置为最大值MAX；- setting the value_Vreg to the maximum value MAX atstep 1020c in response to detecting atstep 1014 that a given LED string is activated for the first time after the system is powered up;

-响应于在步骤1016检测到临时开路负载条件，在步骤1020d增加值V_reg，例如通过将值V_reg设置为最大值MAX或通过将恒定值(诸如先前表格中所示的12或16)加到当前值V_reg；- In response to detecting a temporary open load condition at step 1016, increase the value_Vreg atstep 1020d, eg by setting the value_Vreg to the maximum value MAX or by adding a constant value (such as 12 or 16 as shown in the previous table) to to the current value V_reg ;

-响应于在步骤1018检测到接通持续时间太短而不允许经由(一个或多个)ADC404进行采样，在步骤1020e将值V_reg设置为最大值MAX。- In response to detecting atstep 1018 that the on-duration is too short to allow sampling via the ADC(s) 404, setting the value_Vreg to the maximum value MAX atstep 1020e.

图11还示出，在步骤1030处的开环控制可以包括第一步骤1032，其中，将值V_{32_MIN}与各种范围(参见前面的表)进行比较，以及第二步骤1034，其中，根据值V_{32_MIN}的检测范围将校正因子加到当前值V_reg。Figure 11 also shows that the open loop control atstep 1030 may include afirst step 1032 in which the value V_{32_MIN} is compared to various ranges (see previous table), and asecond step 1034 in which according to the value The detection range of_{V32_MIN adds} a correction factor to the current value_Vreg .

因此，一旦在步骤1020a-1020e、1024、1028或1034中的一个步骤已经更新值Vreg，控制电路40可以进行到等待步骤1036。Thus, once the value Vreg has been updated at one ofsteps 1020a-1020e, 1024, 1028 or 1034,control circuit 40 may proceed to waitstep 1036.

通常，所有更新可以使用相同的等待时间，或者如图所示，不同的等待步骤可以用于值V_reg的不同更新。In general, the same wait time can be used for all updates, or as shown, different wait steps can be used for different updates of the value_Vreg .

举例来说，在所考虑的实施例中，步骤1020a、1020b和1020c进行到步骤1038，其中，控制电路立即将新值V_reg提供到DAC 418。For example, in the embodiment under consideration,steps 1020a, 1020b, and 1020c proceed to step 1038, where the control circuit immediately provides the new value V_reg toDAC 418 .

相反，步骤1020d可进行到步骤1040，其中，控制电路更新提供给DAC 418的V_reg以用于下一PWM周期，或优选地稍微提前进行更新，例如在下一PWM周期开始之前的100us。Conversely,step 1020d may proceed to step 1040, where the control circuit updates_Vreg provided toDAC 418 for the next PWM cycle, or preferably slightly earlier, such as 100us before the start of the next PWM cycle.

最后，在所考虑的实施例中，步骤1024、1028和1034进行到步骤1042，其中，控制电路40等待给定数量的PWM循环，例如，控制电路40可以在给定等待时间(例如，在10与50ms之间选择)之后在下一PWM周期处将新值V_reg提供到DAC 418。例如，可以基于用于将电压V_out调节到新值的调节器20的响应时间来选择等待时间。Finally, in the embodiment under consideration, steps 1024, 1028, and 1034 proceed to step 1042, where thecontrol circuit 40 waits for a given number of PWM cycles, eg, thecontrol circuit 40 may wait for a given waiting time (eg, at 10 and 50ms) and then provide the new value_Vreg to theDAC 418 at the next PWM cycle. For example, the waiting time may be selected based on the response time of theregulator 20 for regulating the voltage V_out to a new value.

通常，由于步骤1012用于通过将值V_reg设置为最小值MIN来基本使输出电压V_out无效，所以该步骤也可以用于检测可能需要使输出电压V_out无效的其他条件。例如，在各种实施例中，控制电路40被配置成响应于检测到以下条件中的一个或多个条件而从步骤1012进行到步骤1020b：电压源20、电流调节器32和/或光源L的过温条件；以及ADC 404和/或DAC414的故障。In general, sincestep 1012 is used to substantially invalidate the output voltage_Vout by setting the value_Vreg to the minimum value MIN, this step can also be used to detect other conditions that may require the output voltage_Vout to be invalidated. For example, in various embodiments,control circuit 40 is configured to proceed fromstep 1012 to step 1020b in response to detecting one or more of the following conditions:voltage source 20 ,current regulator 32 and/or light source L over-temperature conditions; and a malfunction ofADC 404 and/orDAC 414.

因此，在各种实施例中，控制电路40可以被配置成：Thus, in various embodiments, thecontrol circuit 40 may be configured to:

-管理所述装置的启动；- managing the activation of the device;

-当控制电路没有接收到指示所请求的照明模式的数据时，例如通过关断到串34的电流供应来管理待机和故障安全情况；- managing standby and fail-safe conditions, eg by switching off the current supply to thestring 34 when the control circuit does not receive data indicative of the requested lighting mode;

-管理临时或永久的开路负载条件；- manage temporary or permanent open circuit load conditions;

-在危险的加热和/或热关断的情况下，例如在由电流调节器/限制器32耗散过多功率的情况下和/或在电流调节器/限制器32过热的情况下，管理LED上的电流降额过程；- In the event of a dangerous heating and/or thermal shutdown, eg in the event of excessive power being dissipated by the current regulator/limiter 32 and/or in the event of overheating of the current regulator/limiter 32, manage The current derating process on the LED;

-在电池系统的情况下，例如通过减小流过所述串的电流和/或关断所述串34来管理低功率模式；- in the case of a battery system, for example by reducing the current flowing through the string and/or switching off thestring 34 to manage a low power mode;

-例如通过关断相应的串34来管理可能的短路条件；- managing possible short-circuit conditions, eg by switching off the correspondingstring 34;

-管理所述控制信号CTRL的给定条件，例如，以便确保所述占空比足够长，以便允许在相应的接通时段期间对相应的电压V_OUT进行采样。- managing the given conditions of the control signal CTRL, eg to ensure that the duty cycle is long enough to allow the corresponding voltage V_OUT to be sampled during the corresponding on-period.

因此，在先前的实施例中，每个电流供应系统可以用于供应多达N串光源。然而，在典型的应用中，要提供的串的数量也可以大于50，例如，多于100个串。Thus, in the previous embodiments, each current supply system can be used to supply up to N strings of light sources. However, in typical applications, the number of strings to be provided may also be greater than 50, eg, more than 100 strings.

因此，在这种情况下，电流供应系统、例如相应的集成电路，将需要大量的电流调节器/限制器32，这在仅需要供应少量的串34的情况下将是相当无用的。可替代地，串34可以被分成子组，其中，串34的每个子组经由相应的电压源20和相应的电流供应系统来供电。然而，这也涉及附加的成本，因为必须使用额外的电压源。Therefore, in this case, the current supply system, eg the corresponding integrated circuit, would require a large number of current regulators/limiters 32, which would be rather useless when only a small number ofstrings 34 need to be supplied. Alternatively, thestrings 34 may be divided into subgroups, wherein each subgroup of thestrings 34 is powered via acorresponding voltage source 20 and a corresponding current supply system. However, this also involves additional costs, since an additional voltage source must be used.

相反，图12示出模块化系统，其中，单个电压源20和多个电流供应系统(在图12中用附图标记50₁、…、50_k表示)用于向串34供电。例如，如前所述，这种电流供应系统可以在相应的集成电路中实现。In contrast, FIG. 12 shows a modular system in which asingle voltage source 20 and multiple current supply systems (indicated by reference numerals 50₁ , . . . , 50_k in FIG. 12 ) are used to power thestrings 34 . For example, such a current supply system can be implemented in a corresponding integrated circuit, as previously described.

具体地，如前所述，每个电流供应系统50₁、…、50_k包括连接到相应端子OUT1、...、OUTN的N个电流调节器/限制器32，以及被配置成根据端子OUT1、...、OUTN处的电压来设置参考信号V_ref的控制电路40。具体地，控制电路40被配置成根据串34处的最大电压降和/或电流调节器/限制器32处的最小电压降来设置参考信号V_ref。Specifically, as previously mentioned, each current supply system 50₁ , . . . , 50_k includes N current regulators/limiters 32 connected to the respective terminals OUT1 , . . . OUTN, and is configured to , . . , OUTN to set thecontrol circuit 40 of the reference signal_Vref . Specifically, thecontrol circuit 40 is configured to set the reference signal V_ref according to the maximum voltage drop at thestring 34 and/or the minimum voltage drop at the current regulator/limiter 32 .

在这方面，发明人已经观察到，通过使用附加电路，相同的电压源20可以由多个电流供应系统50₁、…、50_k共享，该附加电路被配置成向电压源20提供由各种控制电路44提供的最大参考信号V_ref。In this regard, the inventors have observed that thesame voltage source 20 can be shared by multiple current supply systems 50₁ , . . . 50_k by using additional circuitry configured to provide thevoltage source 20 with various The maximum reference signal V_ref provided by thecontrol circuit 44 .

具体地，如图12所示，在这种情况下，电源系统包括电压源20和连接到同一电压源20的给定数量k的电流供应系统50₁、…、50_k。例如，每个电流供应系统50₁、…、50_k也可以被配置成向N个串供电，从而能够向总共k*N个串供电。Specifically, as shown in FIG. 12 , in this case, the power supply system comprises avoltage source 20 and a given number k of current supply systems 50₁ , . . . , 50_k connected to thesame voltage source 20 . For example, each current supply system 50₁ , . . . , 50_k may also be configured to supply N strings, so that a total of k*N strings can be supplied.

具体地，每个电流供应系统50₁、…、50_k包括各自的控制电路40，控制电路因此生成各自的参考信号V_ref1、...、V_refk。因此，在各种实施例中，电源系统包括电路44，该电路被配置成确定参考信号V_ref1、...、V_refk的最大值并且将该最大值提供给电压源20作为参考信号V_ref。In particular, each current supply system 50₁ , . . . , 50_k includes arespective control circuit 40 , which thus generates a respective reference signal V_ref1 , . . . , V_refk . Thus, in various embodiments, the power supply system includes acircuit 44 configured to determine the maximum value of the reference signals V_ref1 , . . . , V_refk and provide the maximum value to thevoltage source 20 as the reference signal V_ref .

具体地，图12示出实施例，其中，通过在每个电流供应系统50₁、…、50_k内提供子电路44，以分布式方式实现该电路44。具体地，每个电流供应系统50₁、…、50_k包括被配置成连接到电压源20的端子V_ref的相应端子46，即，在使用中这些端子46连接在一起。此外，每个子电路44被配置成，当相应的参考信号V_ref1、...、V_refk大于相应端子46处的电压时，将相应的参考信号V_ref1、...、V_refk施加到相应的端子46。In particular, Figure 12 shows an embodiment in which thecircuit 44 is implemented in a distributed manner by providing a sub-circuit 44 within each current supply system_50i , . . . ,_50k . In particular, each current supply system 50₁ , . . . , 50_k comprises arespective terminal 46 configured to be connected to the terminal V_ref of thevoltage source 20 , ie theterminals 46 are connected together in use. Furthermore, each sub-circuit 44 is configured to apply the respective reference signal V_ref1 , . . . , V_refk to the respective reference signal V_ref1 , . . . , V_refk when the respective reference signal V ref1 , . terminal 46.

例如，图13示出电路44的可能实施例。For example, FIG. 13 shows a possible embodiment ofcircuit 44 .

具体地，在所考虑的实施例中，电路44包括：Specifically, in the embodiment under consideration,circuit 44 includes:

-可变电流源442，诸如场效应晶体管，被配置成根据控制信号生成正电流，其中，电流被提供给电阻器R，并且其中，电阻器R处的电压被施加到端子46；以及- a variablecurrent source 442, such as a field effect transistor, configured to generate a positive current according to the control signal, wherein the current is supplied to the resistor R, and wherein the voltage at the resistor R is applied to the terminal 46; and

-运算放大器440，被配置成在第一(正/非反相)输入处接收被指示为V_refk的相应参考信号，并且在第二(负/反相)输入处接收电阻器R处的电压，其中，运算放大器440的输出控制可变电流源442。- anoperational amplifier 440 configured to receive at a first (positive/non-inverting) input a respective reference signal indicated as_Vrefk and at a second (negative/inverting) input the voltage at resistor R , where the output ofoperational amplifier 440 controls variablecurrent source 442 .

因此，在所考虑的实施例中，在端子46处的电压小于参考信号V_refk的情况下，运算放大器440改变电流源442所提供的电流，直到端子46处的电压对应于参考信号V_refk。然而，在端子46处的电压大于参考信号V_refk的情况下，将使电流源442无效并且端子46处的电压将被保持。Thus, in the embodiment under consideration, where the voltage atterminal 46 is less than reference signal_Vrefk ,operational amplifier 440 varies the current provided bycurrent source 442 until the voltage atterminal 46 corresponds to reference signal_Vrefk . However, in the event that the voltage atterminal 46 is greater than the reference signal_Vrefk ,current source 442 will be deactivated and the voltage atterminal 46 will be maintained.

因此，在非常大的LED或OLED系统的情况下，通过仅允许具有最高参考值V_ref的控制电路40来控制电压源20，单个电压源20可以由不同的电流供应系统50共享。Thus, in the case of very large LED or OLED systems, asingle voltage source 20 can be shared by different current supply systems 50 by allowing only thecontrol circuit 40 with the highest reference value_Vref to control thevoltage source 20 .

发明人已经观察到，电压源20的参考电压V_ref通常不是外部可用的。The inventors have observed that the reference voltage_Vref of thevoltage source 20 is generally not externally available.

然而，如图14所示，在这种情况下，控制电路40可以包括或关联反馈适应电路42，反馈适应电路被配置成根据控制电路40提供的参考信号V_ref来适应反馈信号FB。例如，反馈适应电路42可以被配置成：However, as shown in FIG. 14 , in this case thecontrol circuit 40 may include or be associated with afeedback adaptation circuit 42 configured to adapt the feedback signal FB according to the reference signal V_ref provided by thecontrol circuit 40 . For example,feedback adaptation circuit 42 may be configured to:

-如图14所示，适应所述反馈电路24的参考电压，例如，电阻器R1和R2可以串联连接在电压V_out与由反馈适应电路42根据参考信号V_ref提供的电压FB_OUT之间；- as shown in Figure 14, adapting the reference voltage of thefeedback circuit 24, for example, resistors R1 and R2 may be connected in series between the voltage_Vout and the voltage FB_OUT provided by thefeedback adaptation circuit 42 according to the reference signal_Vref ;

-在电阻器R2中注入电流，从而改变电阻器R2处的电压降；- inject current in resistor R2, thereby changing the voltage drop at resistor R2;

-改变所述电阻器R1和/或R2的电阻。- changing the resistance of said resistors R1 and/or R2.

权利要求是本文提供的本公开的技术教导的集成部分。The claims are an integral part of the technical teachings of the disclosure provided herein.

当然，在不损害本发明的原理的情况下，构造和实施例的细节可以相对于在此仅通过示例描述和例示的内容而广泛地变化，而不由此脱离由所附权利要求限定的本发明的范围。Of course, without prejudice to the principles of the invention, the details of construction and implementation may vary widely with respect to what has been described and illustrated herein by way of example only, without thereby departing from the invention as defined by the appended claims range.

Claims (12)

Translated fromChinese

1.一种电流供应系统，包括：1. A current supply system, comprising:一个或多个第一端子，被配置成连接到电压源的第一输出端子；one or more first terminals configured to connect to the first output terminal of the voltage source;多个第二端子，其中所述第二端子中的每个第二端子被配置成经由相应的固态光源串连接到所述电压源的第二输出端子；a plurality of second terminals, wherein each of the second terminals is configured to connect to a second output terminal of the voltage source via a corresponding string of solid state light sources;第三端子，被配置成向所述电压源提供参考信号，所述参考信号指示将由所述电压源在所述电压源的所述第一输出端子与所述第二输出端子之间生成的所请求的输出电压；a third terminal configured to provide a reference signal to the voltage source, the reference signal indicative of the output voltage to be generated by the voltage source between the first output terminal and the second output terminal of the voltage source the requested output voltage;多个电流调节器或限制器，其中所述第二端子中的每个第二端子经由相应的电流调节器或限制器连接到所述一个或多个第一端子中的至少一个第一端子，其中所述电流调节器或限制器中的每个电流调节器或限制器被配置成将流经连接到相应的所述第二端子上的所述固态光源串的电流限制到相应的最大值；以及a plurality of current regulators or limiters, wherein each of the second terminals is connected to at least one of the one or more first terminals via a respective current regulator or limiter, wherein each of the current regulators or limiters is configured to limit the current flowing through the string of solid state light sources connected to the corresponding second terminal to a corresponding maximum value; as well as控制电路，被配置成生成所述参考信号，并且包括：a control circuit configured to generate the reference signal and comprising:至少一个模数转换器，被配置成获得所述第二端子处的电压的数字样本、以及所述电压源的所述第一输出端子与所述第二输出端子之间的电压的数字样本；at least one analog-to-digital converter configured to obtain a digital sample of the voltage at the second terminal and a digital sample of the voltage between the first output terminal and the second output terminal of the voltage source;数模转换电路，被配置成接收数字调节值，并提供所述参考信号；a digital-to-analog conversion circuit configured to receive the digital adjustment value and provide the reference signal;前馈控制电路，被配置成：通过根据所述数字样本确定所述第二端子与所述电压源的所述第二输出端子之间的最大电压降、并且将给定的裕量添加到所述最大电压降，来计算指示所请求的所述输出电压的前馈调节值，以及a feedforward control circuit configured to: by determining a maximum voltage drop between the second terminal and the second output terminal of the voltage source from the digital samples, and adding a given margin to the the maximum voltage drop to calculate a feedforward regulation value indicative of the requested output voltage, and反馈控制电路，被配置成根据所述数字样本确定所述多个电流调节器或限制器处的最小电压降、并且根据所述最小电压降与所述裕量之间的差确定反馈校正值；a feedback control circuit configured to determine a minimum voltage drop at the plurality of current regulators or limiters based on the digital samples, and to determine a feedback correction value based on a difference between the minimum voltage drop and the headroom;其中所述控制电路被配置成响应于所述电流供应系统的启动，将所述数字调节值设置为指示所请求的最大输出电压的第一值，并且然后重复以下操作：wherein the control circuit is configured to, in response to activation of the current supply system, set the digital adjustment value to a first value indicative of a requested maximum output voltage, and then repeat the following operations:确定所述数字调节值是否对应于所述第一值；determining whether the digital adjustment value corresponds to the first value;如果所述数字调节值大于或等于所述第一值，则将所述数字调节值设置为所述前馈值；并且if the digital adjustment value is greater than or equal to the first value, setting the digital adjustment value to the feedforward value; and如果所述数字调节值小于所述第一值，则将所述反馈校正值加到所述数字调节值。If the digital adjustment value is less than the first value, the feedback correction value is added to the digital adjustment value.2.根据权利要求1所述的电流供应系统，其中所述电流调节器或限制器中的每个电流调节器或限制器被配置成从所述控制电路接收至少一个控制信号，所述至少一个控制信号指示至少第一操作模式和第二操作模式，其中：2. The current supply system of claim 1, wherein each of the current regulators or limiters is configured to receive at least one control signal from the control circuit, the at least one The control signal indicates at least a first mode of operation and a second mode of operation, wherein:其中相应的所述电流调节器或限制器被配置成，如果所述至少一个控制信号指示所述第一操作模式，则使所述电流无效；并且wherein the respective said current regulator or limiter is configured to disable said current if said at least one control signal indicates said first mode of operation; and其中相应的所述电流调节器或限制器被配置成，如果所述至少一个控制信号指示所述第二操作模式，则将所述电流限制到相应的所述最大值。wherein the respective said current regulator or limiter is configured to limit the said current to the respective said maximum value if the at least one control signal indicates the second mode of operation.3.根据权利要求2所述的电流供应系统，其中所述至少一个控制信号包括脉宽调制信号，其中所述脉宽调制信号的第一逻辑电平指示所述第一操作模式，并且其中所述脉宽调制信号的第二逻辑电平指示所述第二操作模式。3. The current supply system of claim 2, wherein the at least one control signal comprises a pulse width modulated signal, wherein a first logic level of the pulse width modulated signal is indicative of the first mode of operation, and wherein the The second logic level of the pulse width modulated signal is indicative of the second mode of operation.4.根据权利要求2所述的电流供应系统，其中所述至少一个控制信号指示所述最大值。4. The current supply system of claim 2, wherein the at least one control signal indicates the maximum value.5.根据权利要求2所述的电流供应系统，其中所述控制电路被配置成：5. The current supply system of claim 2, wherein the control circuit is configured to:确定所述控制信号是否指示所述电流调节器或限制器应当使用所述第一操作模式；并且determining whether the control signal indicates that the current regulator or limiter should use the first mode of operation; and如果所述控制信号指示所述电流调节器或限制器应当使用所述第一操作模式，则将所述数字调节值设置为指示所请求的最小输出电压的第二值。If the control signal indicates that the current regulator or limiter should use the first mode of operation, the digital adjustment value is set to a second value indicative of a requested minimum output voltage.6.根据权利要求5所述的电流供应系统，其中所述控制电路被配置成：6. The current supply system of claim 5, wherein the control circuit is configured to:如果所述控制信号指示所述电流调节器或限制器中的至少一个电流调节器或限制器应当使用所述第二操作模式，则确定所述数字调节值是否对应于所述第二值；并且determining whether the digital adjustment value corresponds to the second value if the control signal indicates that at least one of the current regulators or limiters should use the second mode of operation; and如果所述数字调节值对应于所述第二值，则将所述数字调节值设置为所述第一值。If the digital adjustment value corresponds to the second value, the digital adjustment value is set to the first value.7.根据权利要求2所述的电流供应系统，其中所述控制电路被配置成：7. The current supply system of claim 2, wherein the control circuit is configured to:确定所述控制信号是否指示至少一个电流调节器或限制器应当使用所述第二操作模式；determining whether the control signal indicates that at least one current regulator or limiter should use the second mode of operation;如果所述控制信号指示至少一个电流调节器或限制器应当使用所述第二操作模式，则确定电流是否正在流过应当使用所述第二操作模式的所述至少一个电流调节器或限制器；并且if the control signal indicates that at least one current regulator or limiter should use the second mode of operation, determining whether current is flowing through the at least one current regulator or limiter that should use the second mode of operation; and如果没有电流流过应当使用所述第二操作模式的所述电流调节器或限制器中的至少一个电流调节器或限制器，则改变所述数字调节值以便增加所请求的所述输出电压。If no current flows through at least one of the current regulators or limiters that should use the second operating mode, the digital regulation value is changed to increase the requested output voltage.8.根据权利要求1所述的电流供应系统，其中所述参考信号与将由所述电压源生成的所请求的所述输出电压成比例，并且其中所述数模转换器转换电路包括模数转换器，所述模数转换器被配置成根据所述数字调节值生成所述参考信号。8. The current supply system of claim 1, wherein the reference signal is proportional to the requested output voltage to be generated by the voltage source, and wherein the digital-to-analog converter conversion circuit comprises an analog-to-digital conversion The analog-to-digital converter is configured to generate the reference signal based on the digital adjustment value.9.根据权利要求1所述的电流供应系统，其中所述第三端子被配置成耦联到所述电压源的反馈端子，以便改变指示由所述电压源生成的所述输出电压的反馈信号。9. The current supply system of claim 1, wherein the third terminal is configured to be coupled to a feedback terminal of the voltage source to vary a feedback signal indicative of the output voltage generated by the voltage source .10.一种集成电路，包括根据权利要求1所述的电流供应系统。10. An integrated circuit comprising the current supply system of claim 1.11.一种电源系统，包括：11. A power supply system, comprising:电压源，被配置成在所述电压源的第一输出端子和第二输出端子之间生成输出电压，其中所述电压源被配置成根据参考信号生成所述输出电压；以及a voltage source configured to generate an output voltage between a first output terminal and a second output terminal of the voltage source, wherein the voltage source is configured to generate the output voltage based on a reference signal; and根据权利要求1所述的电流供应系统。The current supply system of claim 1 .12.根据权利要求11所述的电源系统，包括：12. The power supply system of claim 11, comprising:多个固态光源串，其中每个固态光源串被连接在相应的第二端子与所述电压源的所述第二输出端子之间。A plurality of strings of solid state light sources, wherein each string of solid state light sources is connected between a corresponding second terminal and the second output terminal of the voltage source.

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