TWI847604B

TWI847604B - Circuit for measuring the supply voltage of the power supply terminal of LED control chip

Info

Publication number: TWI847604B
Application number: TW112109836A
Authority: TW
Inventors: 李可; 李萌; 李卓研
Original assignee: 大陸商昂寶電子（上海）有限公司
Priority date: 2022-12-29
Filing date: 2023-03-16
Publication date: 2024-07-01

Abstract

本發明提供一種用於發光二極體(Light-emitting diode,LED)控制晶片的測量供電端的供電電壓的電路。供電端經由LED控制晶片的高壓引腳向連接到LED控制晶片的電源引腳的儲能器件供電，以使得儲能器件經由電源引腳向LED控制晶片提供工作電流，該電路包括：第一控制單元，連接在高壓引腳與電源引腳之間，用於根據第一控制信號接通或斷開高壓引腳與電源引腳之間的連接；電壓測量單元，連接在高壓引腳與參考地之間，用於根據第二控制信號開啟或停止經由高壓引腳對供電電壓的測量，在第一控制單元接通高壓引腳與電源引腳之間的連接的情況下，電壓測量單元停止對供電電壓的測量；在第一控制單元斷開高壓引腳與電源引腳之間的連接的情況下，電壓測量單元開啟對供電電壓的測量。 The present invention provides a circuit for measuring the power supply voltage of a power supply terminal of a light-emitting diode (LED) control chip. The power supply terminal supplies power to an energy storage device connected to a power supply pin of the LED control chip via a high-voltage pin of the LED control chip, so that the energy storage device provides a working current to the LED control chip via the power supply pin. The circuit includes: a first control unit connected between the high-voltage pin and the power supply pin, and used to connect or disconnect the connection between the high-voltage pin and the power supply pin according to a first control signal; a voltage measuring unit, Connected between the high voltage pin and the reference ground, it is used to start or stop the measurement of the power supply voltage through the high voltage pin according to the second control signal. When the first control unit connects the connection between the high voltage pin and the power supply pin, the voltage measurement unit stops measuring the power supply voltage; when the first control unit disconnects the connection between the high voltage pin and the power supply pin, the voltage measurement unit starts measuring the power supply voltage.

Description

用於LED控制晶片的測量供電端的供電電壓的電路 Circuit for measuring the power supply voltage at the power supply end of LED control chip

本發明涉及電路領域，特別是，涉及一種用於LED控制晶片的測量供電端的供電電壓的電路。 The present invention relates to the field of circuits, and in particular, to a circuit for measuring the power supply voltage of a power supply terminal of an LED control chip.

LED照明已成為人們日常生活中不可或缺的一部分，因而用於為LED供電的LED驅動電路的使用日益廣泛。 LED lighting has become an integral part of people's daily lives, and as a result, LED driver circuits used to power LEDs are becoming increasingly popular.

LED驅動電路通常在LED控制晶片的控制下將外部供電電流轉換為恆定電流來為LED供電。LED控制晶片需要使用供電端的供電電壓為連接到LED控制晶片的電源引腳的儲能器件供電，以使得儲能器件能夠為LED控制晶片提供工作電流。為實現對LED控制晶片的諸如過壓保護等的相關控制，需要對該供電端的供電電壓進行測量。然而，供電電壓的測量通常會受到LED驅動晶片的工作狀態的影響，而導致測量結果不準確，從而影響LED控制晶片的相關控制操作，甚至會對LED控制晶片造成安全隱患。 LED driver circuits usually convert external power supply current into constant current to power LEDs under the control of LED control chips. LED control chips need to use the power supply voltage at the power supply end to power the energy storage device connected to the power pin of the LED control chip, so that the energy storage device can provide working current for the LED control chip. In order to achieve relevant control of the LED control chip, such as overvoltage protection, the power supply voltage at the power supply end needs to be measured. However, the measurement of the power supply voltage is usually affected by the working state of the LED driver chip, resulting in inaccurate measurement results, thereby affecting the relevant control operations of the LED control chip, and even causing safety hazards to the LED control chip.

因此，需要能夠更準確地測量供電端的供電電壓的方式。 Therefore, a method is needed to more accurately measure the power supply voltage at the power supply end.

根據本發明的示例性實施例，提供了一種用於LED控制晶片的測量供電端的供電電壓的電路，所述供電端用於經由所述LED控制晶片的高壓引腳向連接到所述LED控制晶片的電源引腳的儲能器件供電，以使得所述儲能器件經由所述電源引腳向所述LED控制晶片提供工作電流，其中，所述電路包括：第一控制單元，被配置為連接在所述高壓引腳與所述電源引腳之間，用於根據第一控制信號接通或斷開所述高壓引腳與所述電源引腳之間的連接；以及電壓測量單元，被配置為連接在所述高壓引腳與參考地之間，用於根據第二控制信號開啟或停止經由所述高壓引腳對所述供電電壓的測量，其中，在所述第一控制單元接通所述高壓引腳與所述電源引腳之間的連接的情況下，所述電壓測量單元停止經由所述高壓引腳對所述供電電壓的測量；在所述第一控制單元斷開所述高壓引腳與所述電源引腳之間的連接的情況下，所述電壓測量單元開啟經由所述高壓引腳對所述供電電壓的測量。 According to an exemplary embodiment of the present invention, a circuit for measuring a power supply voltage of a power supply terminal of an LED control chip is provided, wherein the power supply terminal is used to supply power to an energy storage device connected to a power supply pin of the LED control chip via a high voltage pin of the LED control chip, so that the energy storage device provides a working current to the LED control chip via the power supply pin, wherein the circuit comprises: a first control unit, configured to be connected between the high voltage pin and the power supply pin, and used to connect or disconnect the high voltage pin and the power supply pin according to a first control signal; connection; and a voltage measuring unit, configured to be connected between the high voltage pin and the reference ground, for starting or stopping the measurement of the power supply voltage via the high voltage pin according to a second control signal, wherein, when the first control unit connects the connection between the high voltage pin and the power supply pin, the voltage measuring unit stops the measurement of the power supply voltage via the high voltage pin; when the first control unit disconnects the connection between the high voltage pin and the power supply pin, the voltage measuring unit starts the measurement of the power supply voltage via the high voltage pin.

根據本發明的示例性實施例的用於LED控制晶片的測量供電端的供電電壓的電路，能夠通過在LED控制晶片的高壓引腳連接到電源引腳從而供電端向連接到電源引腳的儲能器件供電期間，停止對供電端的供電電壓的測量，並在LED控制晶片的高壓引腳與電源引腳的連接斷開從而供電端不向連接到電源引腳的儲能器件供電期間，對供電端的供電電壓進行測量，來防止LED控制晶片的工作狀態對供電電壓測量的影響，從而能夠提高測量供電電壓的準確度。 According to the circuit for measuring the power supply voltage of the power supply end of the LED control chip according to the exemplary embodiment of the present invention, the power supply voltage of the power supply end can be stopped from being measured when the high voltage pin of the LED control chip is connected to the power pin so that the power supply end supplies power to the energy storage device connected to the power pin, and the power supply voltage of the power supply end is measured when the high voltage pin of the LED control chip is disconnected from the power pin so that the power supply end does not supply power to the energy storage device connected to the power pin, so as to prevent the working state of the LED control chip from affecting the power supply voltage measurement, thereby improving the accuracy of measuring the power supply voltage.

100,200:LED控制晶片 100,200:LED control chip

1000:LED驅動電路 1000:LED driver circuit

110,210:電路 110,210: Circuit

120:恆流控制模組 120: Constant flow control module

211:第一控制單元 211: First control unit

212:電壓測量單元 212: Voltage measurement unit

213:限流單元 213: Current limiting unit

214:第二控制單元 214: Second control unit

215:信號生成單元 215:Signal generation unit

A:第一控制信號 A: First control signal

B:第二控制信號 B: Second control signal

C:電容值 C: Capacitance value

C1:第一電容器 C1: First capacitor

C2:存儲單元(第二電容器) C2: Storage unit (second capacitor)

Cvdd:儲能器件 Cvdd: energy storage device

D:汲極 D: Drain

D1:二極體 D1: diode

G:閘極 G: Gate

GATE:閘極引腳 GATE: Gate pin

HV:高壓引腳 HV: High Voltage Pin

I,Ihv:電流 I,Ihv: current

I1:工作電流 I1: Working current

L1:電感器 L1: Inductor

M1,M2:開關 M1,M2: switch

N1:第一節點 N1: First node

Nin:端子 Nin: Terminal

Nin1:輸入端子 Nin1: Input terminal

Nout1:第一輸出端子 Nout1: first output terminal

Nout2:第二輸出端子 Nout2: Second output terminal

R1:第一電阻器 R1: First resistor

R2:第一分壓單元 R2: The first voltage divider unit

R3:第二分壓單元 R3: The second voltage divider unit

Rp:電阻器 Rp: Resistor

S:源極 S: Source

s1:第一開關 s1: First switch

s2:第二開關 s2: Second switch

t,t1,T1,T2,T3:時間 t,t1,T1,T2,T3: time

V1:供電電壓 V1: Power supply voltage

V2:電壓 V2: voltage

Vbus:外部供電線路 Vbus: external power supply line

Vc:測量端子 Vc: measuring terminal

vc1,vc2:分壓 vc1,vc2: voltage divider

VDD:電源引腳 VDD: power pin

Vin:供電端 Vin: power supply end

從下面結合圖式對本發明的具體實施方式的描述中可以更好地理解本發明，其中：圖1示出了根據一個示例性實施例的具有LED驅動晶片的LED驅動電路的示意性電路圖。 The present invention can be better understood from the following description of the specific implementation of the present invention in conjunction with the drawings, wherein: FIG1 shows a schematic circuit diagram of an LED driver circuit with an LED driver chip according to an exemplary embodiment.

圖2示出了根據一個示例性實施例的圖1的電路中的電壓信號和電流信號的波形圖。 FIG2 shows a waveform diagram of a voltage signal and a current signal in the circuit of FIG1 according to an exemplary embodiment.

圖3示出了根據本發明的一個示例性實施例的用於LED控制晶片的測量供電端的供電電壓的電路的示意性框圖。 FIG3 shows a schematic block diagram of a circuit for measuring the power supply voltage at the power supply end of an LED control chip according to an exemplary embodiment of the present invention.

圖4示出了根據本發明的一個示例性實施例的用於LED控制晶片的測量供電端的供電電壓的電路的示意性電路圖。 FIG4 shows a schematic circuit diagram of a circuit for measuring the power supply voltage of a power supply terminal of an LED control chip according to an exemplary embodiment of the present invention.

圖5示出了根據本發明的一個示例性實施例的圖4的電路中的電壓信號和電流信號的波形圖。 FIG5 shows a waveform diagram of a voltage signal and a current signal in the circuit of FIG4 according to an exemplary embodiment of the present invention.

下面將詳細描述本發明的各個方面的特徵和示例性實施例。在下面的詳細描述中，提出了許多具體細節，以便提供對本發明的全面理解。但是，對於本領域技術人員來說很明顯的是，本發明可以在不需要這些具體細節中的一些細節的情況下實施。下面對實施例的描述僅僅是為了通過示出本發明的示例來提供對本發明的更好的理解。本發明決不限於下面所提出的任何具體配置和演算法，而是在不脫離本發明的精神的前提下覆蓋了元素、部件和演算法的任何修改、替換和改進。在圖式和下面的描述中，沒有示出公知的結構和技術，以便避免對本發明造成不必要的模糊。 The features and exemplary embodiments of various aspects of the present invention are described in detail below. In the detailed description below, many specific details are set forth in order to provide a comprehensive understanding of the present invention. However, it is obvious to a person skilled in the art that the present invention can be implemented without some of these specific details. The following description of the embodiments is only for the purpose of providing a better understanding of the present invention by illustrating examples of the present invention. The present invention is in no way limited to any specific configuration and algorithm set forth below, but covers any modification, substitution and improvement of elements, components and algorithms without departing from the spirit of the present invention. In the drawings and the following description, well-known structures and techniques are not shown in order to avoid unnecessary ambiguity of the present invention.

圖1示出了根據一個示例性實施例的具有LED控制晶片100的LED驅動電路1000的示意性電路圖。 FIG1 shows a schematic circuit diagram of an LED driving circuit 1000 having an LED control chip 100 according to an exemplary embodiment.

如圖1所示，LED驅動電路1000經由輸入端子Nin1連接到外部供電線路Vbus，並經由第一輸出端子Nout1和第二輸出端子Nout2連接到LED，以使用外部供電線路Vbus的電力為LED供電。外部供電線路Vbus提供的電力可以是經過整流後的市電等。 As shown in FIG1 , the LED driving circuit 1000 is connected to the external power supply line Vbus via the input terminal Nin1, and is connected to the LED via the first output terminal Nout1 and the second output terminal Nout2, so as to use the power of the external power supply line Vbus to power the LED. The power provided by the external power supply line Vbus can be rectified mains power, etc.

LED驅動電路1000具有LED控制晶片100，並可利用LED控制晶片100將外部供電線路Vbus的電流轉換為用於為LED供電的恆定電流。例如，LED控制晶片100的恆流控制模組120可經由閘極引腳GATE連接到恆流開關M2的閘極G，並用於向恆流開關M2的閘極G提供控制信號，以通過控制恆流開關M2的接通或斷開來產生用於向LED供電的恆定電流。 The LED driver circuit 1000 has an LED control chip 100, and can use the LED control chip 100 to convert the current of the external power supply line Vbus into a constant current for powering the LED. For example, the constant current control module 120 of the LED control chip 100 can be connected to the gate G of the constant current switch M2 via the gate pin GATE, and is used to provide a control signal to the gate G of the constant current switch M2 to generate a constant current for powering the LED by controlling the connection or disconnection of the constant current switch M2.

為了使LED控制晶片100獲得工作所需的電力，LED控制晶片100的高壓引腳HV可連接到外部供電線路Vbus，以通過外部供電線路Vbus向連接到LED控制晶片100的電源引腳VDD的儲能器件(例如，儲能器件Cvdd)供電，以使得儲能器件Cvdd經由電源引腳VDD向LED控制晶片100提供工作電流。例如，如圖1所示，在LED控制晶片100中，高壓引腳HV可通過開關M1連接到電源引腳VDD，電源引腳VDD連接到作為儲能器件的儲能器件Cvdd。 In order for the LED control chip 100 to obtain the power required for operation, the high voltage pin HV of the LED control chip 100 can be connected to the external power supply line Vbus to supply power to the energy storage device (e.g., energy storage device Cvdd) connected to the power pin VDD of the LED control chip 100 through the external power supply line Vbus, so that the energy storage device Cvdd provides the working current to the LED control chip 100 via the power pin VDD. For example, as shown in FIG. 1 , in the LED control chip 100, the high voltage pin HV can be connected to the power pin VDD through the switch M1, and the power pin VDD is connected to the energy storage device Cvdd as the energy storage device.

為了向LED控制晶片100提供靜電釋放(Electrostatic Discharge,ESD)保護，並防止從LED控制晶片100向外部供電線路Vbus的電流倒流，可在外部供電線路Vbus與高壓引腳HV之間設置電阻器Rp。例如，在外部供電線路Vbus的供電電壓為高壓、例如平均電壓大於300V時，電阻器Rp可具有1-20K歐姆的阻值。此時，開關M1可以是高壓器件，例如，具有大於500V的工作電壓的高壓器件。 In order to provide electrostatic discharge (ESD) protection to the LED control chip 100 and prevent the current from flowing back from the LED control chip 100 to the external power supply line Vbus, a resistor Rp can be set between the external power supply line Vbus and the high voltage pin HV. For example, when the power supply voltage of the external power supply line Vbus is high voltage, such as an average voltage greater than 300V, the resistor Rp can have a resistance of 1-20K ohms. At this time, the switch M1 can be a high voltage device, for example, a high voltage device with an operating voltage greater than 500V.

由於需要對LED晶片進行諸如過壓保護等的相關控制，因此需要對外部供電線路Vbus的供電電壓進行測量。例如，如圖1所示，可通過串聯連接在高壓引腳HV與參考地之間的第一分壓單元R2和第二分壓單元R3對高壓引腳HV處的電壓進行分壓的方式，來經由測量端子Vc測量高壓引腳HV處的電壓的分壓，從而測量外部供電線路Vbus的供電電壓。 Since the LED chip needs to be controlled for overvoltage protection, the power supply voltage of the external power supply line Vbus needs to be measured. For example, as shown in Figure 1, the voltage at the high voltage pin HV can be divided by the first voltage divider R2 and the second voltage divider R3 connected in series between the high voltage pin HV and the reference ground, and the voltage at the high voltage pin HV can be measured through the measurement terminal Vc, thereby measuring the power supply voltage of the external power supply line Vbus.

然而，在開關M1接通的情況下，外部供電線路Vbus向儲能器件Cvdd供電，電阻器Rp上流過的電流Ihv為LED控制晶片100的工作電流，因而電阻器Rp兩端會具有相應的電壓降。此外，LED控制晶片100的工作電流會由於LED控制晶片的不同操作或不同工作狀態而變化。例如，在LED控制晶片100控制開關M2接通的瞬間、控制開關M2處於接通狀態期間、控制開關M2斷開的瞬間以及控制開關M2處於斷開狀態期間，LED控制晶片100的工作電流互不相同。此外，在LED控制晶片100處於啟動狀態、正常工作狀態、保護狀態、以及快速回應狀態下時，LED控制晶片100的工作電流也互不相同。LED控制晶片100的不斷變化的工作電流會導致電阻器Rp上的電壓降不斷變化，從而導致經由測量端子Vc測量的供電電壓不準確，而這可能會導致LED控制晶片產生誤判斷進而引起誤操作，甚至對LED控制晶片造成安全隱患。 However, when the switch M1 is turned on, the external power supply line Vbus supplies power to the energy storage device Cvdd, and the current Ihv flowing through the resistor Rp is the operating current of the LED control chip 100, so there will be a corresponding voltage drop at both ends of the resistor Rp. In addition, the operating current of the LED control chip 100 will change due to different operations or different working states of the LED control chip. For example, the operating current of the LED control chip 100 is different when the control switch M2 of the LED control chip 100 is turned on, when the control switch M2 is in the on state, when the control switch M2 is turned off, and when the control switch M2 is in the off state. In addition, when the LED control chip 100 is in the startup state, normal working state, protection state, and quick response state, the operating current of the LED control chip 100 is also different. The constantly changing working current of the LED control chip 100 will cause the voltage drop on the resistor Rp to constantly change, resulting in inaccurate supply voltage measured through the measuring terminal Vc, which may cause the LED control chip to misjudge and cause misoperation, or even cause safety hazards to the LED control chip.

如圖2所示，外部供電線路Vbus具有供電電壓V1，在時間t1之前(圖2的時間t1的左側)，開關M1處於斷開狀態，外部供電線路Vbus未向儲能器件Cvdd供電。圖1中的第一分壓單元R2的阻值與第二分壓單元R3的阻值之和可設置得遠遠大於電阻器Rp的阻值，因而在時間t1之前，流經電阻器Rp的電流Ihv可近似為0，電阻器Rp的電壓降可忽略，高壓引腳HV處的電壓可近似為外部供電線路Vbus的供電電壓V1。此時，在測量端子Vc處測量的分壓vc1可以為vc1=V1×R2/(R2+R3)，應該理解，該等式中的R2和R3分別表示第一分壓單元R2和第二分壓單元R3的阻值。 As shown in FIG2 , the external power supply line Vbus has a power supply voltage V1. Before time t1 (to the left of time t1 in FIG2 ), the switch M1 is in an open state, and the external power supply line Vbus does not supply power to the energy storage device Cvdd. The sum of the resistance of the first voltage divider R2 and the resistance of the second voltage divider R3 in FIG1 can be set to be much larger than the resistance of the resistor Rp. Therefore, before time t1, the current Ihv flowing through the resistor Rp can be approximately 0, the voltage drop of the resistor Rp can be ignored, and the voltage at the high voltage pin HV can be approximately equal to the power supply voltage V1 of the external power supply line Vbus. At this time, the voltage divider vc1 measured at the measuring terminal Vc can be vc1=V1×R2/(R2+R3). It should be understood that R2 and R3 in this equation represent the resistance values of the first voltage divider unit R2 and the second voltage divider unit R3, respectively.

在時間t1之時以及之後(圖2的時間t1的右側)，開關M1處於接通狀態，外部供電線路Vbus向儲能器件Cvdd供電，此時，流經電阻器Rp的電流Ihv為LED控制晶片100的工作電流I1。相應地，電阻器Rp上的電壓降導致高壓引腳HV處的電壓從供電電壓V1下降到電壓V2。在測量端子Vc處測量的分壓由vc1變為vc2=(V1-I1×Rp)×R2/(R2+R3)。因此，在外部供電線路Vbus向儲能器件Cvdd供電期間，在LED控制晶片100的工作電流I1不斷變化時，經由測量端子Vc測量的供電電壓隨之變化而非常不準確。 At and after time t1 (to the right of time t1 in FIG. 2 ), the switch M1 is in the on state, and the external power supply line Vbus supplies power to the energy storage device Cvdd. At this time, the current Ihv flowing through the resistor Rp is the operating current I1 of the LED control chip 100. Correspondingly, the voltage drop across the resistor Rp causes the voltage at the high voltage pin HV to drop from the power supply voltage V1 to the voltage V2. The voltage division measured at the measurement terminal Vc changes from vc1 to vc2=(V1-I1×Rp)×R2/(R2+R3). Therefore, when the external power supply line Vbus supplies power to the energy storage device Cvdd, when the working current I1 of the LED control chip 100 changes continuously, the power supply voltage measured through the measurement terminal Vc changes accordingly and is very inaccurate.

為了至少部分地克服上述缺陷，根據本發明的示例性實施例提供了一種用於LED控制晶片的測量供電端的供電電壓的電路。 In order to at least partially overcome the above-mentioned defects, a circuit for measuring the power supply voltage of the power supply terminal of an LED control chip is provided according to an exemplary embodiment of the present invention.

圖3示出了根據本發明的一個示例性實施例的用於LED控制晶片200的測量供電端的供電電壓的電路210的示意性框圖。 FIG3 shows a schematic block diagram of a circuit 210 for measuring the power supply voltage at the power supply end of an LED control chip 200 according to an exemplary embodiment of the present invention.

如圖3所示的供電端Vin用於經由LED控制晶片200的高壓引腳HV向連接到LED控制晶片200的電源引腳VDD的儲能器件供電，以使得儲能器件經由電源引腳VDD向LED控制晶片200提供工作電流。 As shown in FIG3 , the power supply terminal Vin is used to supply power to the energy storage device connected to the power pin VDD of the LED control chip 200 via the high voltage pin HV of the LED control chip 200, so that the energy storage device provides the working current to the LED control chip 200 via the power pin VDD.

在一個實施例中，儲能器件Cvdd可以為第一電容器C1(例如，圖1所示的儲能器件Cvdd)，第一電容器C1連接在電源引腳VDD與參考地之間。 In one embodiment, the energy storage device Cvdd can be a first capacitor C1 (for example, the energy storage device Cvdd shown in FIG. 1 ), and the first capacitor C1 is connected between the power pin VDD and the reference ground.

在一個實施例中，LED控制晶片200可用於LED驅動電路，LED驅動電路用於將外部供電線路的電流轉換為恆定電流以為LED供電。例如，LED驅動電路可以為圖1所示的驅動電路，外部供電線路可以為圖 1所示的外部供電線路Vbus。 In one embodiment, the LED control chip 200 can be used in an LED driving circuit, and the LED driving circuit is used to convert the current of the external power supply circuit into a constant current to power the LED. For example, the LED driving circuit can be the driving circuit shown in FIG. 1, and the external power supply circuit can be the external power supply circuit Vbus shown in FIG. 1.

在一個實施例中，供電端Vin可以為外部供電線路Vbus的用於連接到LED控制晶片200的端子(例如，圖1所示的輸入端子Nin1)，或者供電端Vin可以為LED驅動電路的能夠向LED控制晶片200提供供電電壓的預定端子。供電電壓的平均電壓值可以大於第二電壓值。 In one embodiment, the power supply terminal Vin may be a terminal of the external power supply line Vbus for connecting to the LED control chip 200 (for example, the input terminal Nin1 shown in FIG. 1 ), or the power supply terminal Vin may be a predetermined terminal of the LED driving circuit capable of providing a power supply voltage to the LED control chip 200. The average voltage value of the power supply voltage may be greater than the second voltage value.

例如，在供電端Vin為外部供電線路Vbus的輸入端子Nin1的情況下，供電電壓可以為整流後的市電，該供電電壓的平均電壓值可大於300V。 For example, when the power supply terminal Vin is the input terminal Nin1 of the external power supply line Vbus, the power supply voltage can be the rectified mains power, and the average voltage value of the power supply voltage can be greater than 300V.

在供電端Vin為LED驅動電路的能夠向LED控制晶片200提供供電電壓的預定端子的情況下，在一個實施例中，該預定端子可以為LED控制晶片200的恆流開關(例如，圖1所示的開關M2)的汲極D。與圖1所示相似地，恆流開關M2的閘極G可連接到LED控制晶片200的恆流控制模組120，恆流開關M2的汲極D可經由二極體D1連接到LED驅動電路的第一輸出端子Nout1，並經由電感器L1連接到LED驅動電路的第二輸出端子Nout2，恆流開關M2的源極S可連接到參考地。外部供電線路Vbus可連接到第一輸出端子Nout1，第一輸出端子Nout1和第二輸出端子Nout2可用於連接LED。在這種情況下，例如，供電電壓的平均電壓值可大於500V。 In the case where the power supply terminal Vin is a predetermined terminal of the LED driving circuit capable of providing a power supply voltage to the LED control chip 200, in one embodiment, the predetermined terminal may be a drain D of a constant current switch (e.g., the switch M2 shown in FIG. 1 ) of the LED control chip 200. Similar to FIG. 1 , a gate G of the constant current switch M2 may be connected to the constant current control module 120 of the LED control chip 200, a drain D of the constant current switch M2 may be connected to a first output terminal Nout1 of the LED driving circuit via a diode D1, and to a second output terminal Nout2 of the LED driving circuit via an inductor L1, and a source S of the constant current switch M2 may be connected to a reference ground. The external power supply line Vbus can be connected to the first output terminal Nout1, and the first output terminal Nout1 and the second output terminal Nout2 can be used to connect the LED. In this case, for example, the average voltage value of the power supply voltage can be greater than 500V.

換言之，圖3所示的電路210可用於替代圖1所示的電路110，並且圖3所示的LED控制晶片200的其它部分可以與圖1所示的LED控制晶片100的其它部分相同。或者，圖3所示的電路210可適用於圖1所示的LED驅動電路的變形電路，例如，圖3所示的電路210的供電端Vin可不連接到圖1所示的外部供電線路Vbus，而是如上所述地連接到圖1所示的開關M2的汲極D，以在開關M2斷開的情況下，通過開關M2的汲極處的電壓為第一電容器C1(儲能器件Cvdd)供電，並在開關M2斷開的情況下使用根據本發明的示例性實施例的電路210。應該理解，圖1和圖3所示的LED控制晶片還可包括未示出的其他模組。 In other words, the circuit 210 shown in FIG. 3 can be used to replace the circuit 110 shown in FIG. 1, and the other parts of the LED control chip 200 shown in FIG. 3 can be the same as the other parts of the LED control chip 100 shown in FIG. 1. Alternatively, the circuit 210 shown in FIG. 3 can be applied to a modified circuit of the LED driving circuit shown in FIG. 1. For example, the power supply terminal Vin of the circuit 210 shown in FIG. 3 can be connected to the drain D of the switch M2 shown in FIG. 1 instead of the external power supply line Vbus shown in FIG. 1 as described above, so that when the switch M2 is disconnected, the voltage at the drain of the switch M2 is used to supply power to the first capacitor C1 (energy storage device Cvdd), and the circuit 210 according to the exemplary embodiment of the present invention is used when the switch M2 is disconnected. It should be understood that the LED control chip shown in FIG. 1 and FIG. 3 may also include other modules not shown.

參照圖3，根據本發明的示例性實施例的用於LED控制晶片200的測量供電端的供電電壓的電路210可包括：第一控制單元211和電壓測量單元212。 Referring to FIG. 3 , the circuit 210 for measuring the power supply voltage of the power supply terminal of the LED control chip 200 according to the exemplary embodiment of the present invention may include: a first control unit 211 and a voltage measurement unit 212.

第一控制單元211可被配置為連接在高壓引腳HV與電源引腳VDD之間，用於根據第一控制信號(例如，圖4所示的信號A)接通或斷開高壓引腳HV與電源引腳VDD之間的連接。 The first control unit 211 can be configured to be connected between the high voltage pin HV and the power pin VDD, and is used to connect or disconnect the connection between the high voltage pin HV and the power pin VDD according to the first control signal (for example, signal A shown in FIG. 4).

電壓測量單元212可被配置為連接在高壓引腳HV與參考地之間，用於根據第二控制信號(例如，圖4所示的信號B)開啟或停止經由高壓引腳HV對供電電壓的測量。 The voltage measurement unit 212 can be configured to be connected between the high voltage pin HV and the reference ground, and is used to start or stop the measurement of the power supply voltage through the high voltage pin HV according to the second control signal (for example, signal B shown in FIG. 4 ).

在一個實施例中，在第一控制單元211接通高壓引腳HV與電源引腳VDD之間的連接的情況下，電壓測量單元212停止經由高壓引腳HV對供電電壓的測量；在第一控制單元211斷開高壓引腳HV與電源引腳VDD之間的連接的情況下，電壓測量單元212開啟經由高壓引腳HV對供電電壓的測量。 In one embodiment, when the first control unit 211 connects the connection between the high voltage pin HV and the power pin VDD, the voltage measurement unit 212 stops measuring the power supply voltage through the high voltage pin HV; when the first control unit 211 disconnects the connection between the high voltage pin HV and the power pin VDD, the voltage measurement unit 212 starts measuring the power supply voltage through the high voltage pin HV.

以下參照圖4詳細描述電路210的一個示例性實施例。 An exemplary embodiment of the circuit 210 is described in detail below with reference to FIG. 4 .

圖4示出了根據本發明的一個示例性實施例的用於LED控制晶片200的測量供電端的供電電壓的電路210的示意性電路圖。 FIG4 shows a schematic circuit diagram of a circuit 210 for measuring the power supply voltage of the power supply terminal of an LED control chip 200 according to an exemplary embodiment of the present invention.

在以上的實施例中，LED控制晶片所用於的LED驅動電路可以具有大於預定值的功率因數(例如，大於0.9或其他值)。供電電壓可以為隨時間變化的電壓，例如，具有類似於正弦波的波形的電壓(例如，整流後的市電)。 In the above embodiments, the LED driving circuit used by the LED control chip can have a power factor greater than a predetermined value (for example, greater than 0.9 or other values). The supply voltage can be a voltage that varies with time, for example, a voltage with a waveform similar to a sine wave (for example, rectified mains electricity).

在這種情況下，如圖4所示，電路210還可包括：限流單元213，限流單元213可被配置為連接在供電端Vin與高壓引腳HV之間，用於通過限制供電端Vin與高壓引腳HV之間的電流大小，來對LED控制晶片200提供靜電釋放(ESD)保護，並限制在供電電壓變化的過程中(例如，在供電電壓為0時)從LED控制晶片200向供電端Vin的電流倒流。在一個實施例中，限流單元213可以為具有第一阻值的第一電阻器R1，例如，圖1中的電阻器Rp。 In this case, as shown in FIG. 4 , the circuit 210 may further include: a current limiting unit 213, which may be configured to be connected between the power supply terminal Vin and the high voltage pin HV, and is used to provide electrostatic discharge (ESD) protection to the LED control chip 200 by limiting the current between the power supply terminal Vin and the high voltage pin HV, and to limit the current backflow from the LED control chip 200 to the power supply terminal Vin during the change of the power supply voltage (for example, when the power supply voltage is 0). In one embodiment, the current limiting unit 213 may be a first resistor R1 having a first resistance, for example, the resistor Rp in FIG. 1 .

如圖4所示，在一個實施例中，電壓測量單元212可包括：分壓單元和測量單元。 As shown in FIG. 4 , in one embodiment, the voltage measurement unit 212 may include: a voltage dividing unit and a measurement unit.

分壓單元可被配置為連接在高壓引腳HV與參考地之間，用於對高壓引腳HV處的電壓進行分壓。測量單元可被配置為連接到該分壓單元，用於根據第二控制信號B開啟或停止經由測量高壓引腳HV處的電壓的分壓而對供電電壓的測量。 The voltage divider unit can be configured to be connected between the high voltage pin HV and the reference ground to divide the voltage at the high voltage pin HV. The measuring unit can be configured to be connected to the voltage divider unit to start or stop measuring the power supply voltage by measuring the voltage division at the high voltage pin HV according to the second control signal B.

在一個實施例中，分壓單元可包括：第一分壓單元R2和第二分壓單元R3。 In one embodiment, the voltage dividing unit may include: a first voltage dividing unit R2 and a second voltage dividing unit R3.

第一分壓單元R2可被配置為連接在高壓引腳HV與第一節點N1之間。在一個實施例中，第一分壓單元可以為具有第二阻值的第一分壓單元R2，該第一分壓單元R2可與圖1中的第一分壓單元R2相同。 The first voltage dividing unit R2 may be configured to be connected between the high voltage pin HV and the first node N1. In one embodiment, the first voltage dividing unit may be a first voltage dividing unit R2 having a second resistance value, and the first voltage dividing unit R2 may be the same as the first voltage dividing unit R2 in FIG. 1 .

第二分壓單元R3可被配置為連接在第一節點N1與參考地之間，第一節點N1處的電壓為高壓引腳HV處的電壓的分壓。在一個實施例中，第二分壓單元R3可以為具有第三阻值的第二分壓單元R3，該第二分壓單元R3可與圖1中的第二分壓單元R3相同。在一個實施例中，以上第二阻值與第三阻值之和可比第一阻值大至少第二數量級，即(R2+R3)>>R1，該不等式中的R1、R2和R3分別表示第一阻值、第二阻值和第三阻值。 The second voltage divider R3 can be configured to be connected between the first node N1 and the reference ground, and the voltage at the first node N1 is a voltage divided by the voltage at the high voltage pin HV. In one embodiment, the second voltage divider R3 can be a second voltage divider R3 with a third resistance value, and the second voltage divider R3 can be the same as the second voltage divider R3 in Figure 1. In one embodiment, the sum of the above second resistance value and the third resistance value can be at least a second order of magnitude greater than the first resistance value, that is, (R2+R3)>>R1, and R1, R2 and R3 in the inequality represent the first resistance value, the second resistance value and the third resistance value, respectively.

在工作電流為隨時間變化的電流的情況下，在第一控制單元 211接通高壓引腳HV與電源引腳VDD之間的連接時，限流單元213(第一電阻器R1(Rp))可具有(流過)工作電流，測量單元可停止對供電電壓的測量。在第一控制單元211斷開高壓引腳HV與電源引腳VDD之間的連接時，限流單元213可具有(流過)比工作電流小至少第一數量級的電流(即，遠小於工作電流的近似為0的電流)，測量單元可開啟對供電電壓的測量。 In the case where the working current is a current that varies with time, when the first control unit 211 connects the connection between the high voltage pin HV and the power pin VDD, the current limiting unit 213 (first resistor R1 (Rp)) may have (flow) the working current, and the measuring unit may stop measuring the power supply voltage. When the first control unit 211 disconnects the connection between the high voltage pin HV and the power pin VDD, the current limiting unit 213 may have (flow) a current that is at least a first order of magnitude smaller than the working current (i.e., a current that is much smaller than the working current and is approximately 0), and the measuring unit may start measuring the power supply voltage.

通過以上設置，可僅在供電端Vin不向第一電容器C1供電時，即流過第一電阻器R1的電流很小、從而可忽略第一電阻器R1的電壓降時，才開啟對供電電壓的測量，從而使得該測量不會受到LED控制晶片的工作電流的變化的影響，使得測量更準確。 Through the above settings, the measurement of the supply voltage can be turned on only when the power supply terminal Vin does not supply power to the first capacitor C1, that is, when the current flowing through the first resistor R1 is very small and the voltage drop of the first resistor R1 can be ignored, so that the measurement will not be affected by the change of the working current of the LED control chip, making the measurement more accurate.

在一個實施例中，測量單元可包括：第一開關s1和存儲單元C2。 In one embodiment, the measuring unit may include: a first switch s1 and a storage unit C2.

第一開關s1可被配置為連接在第一節點N1與測量端子Vc之間，用於根據第二控制信號B接通或斷開，以在第一開關s1接通的情況下經由測量端子Vc來測量高壓引腳HV處的電壓的分壓。由於(R2+R3)>>R1，因此該分壓可被視為與供電電壓對應。 The first switch s1 can be configured to be connected between the first node N1 and the measuring terminal Vc, and is used to be turned on or off according to the second control signal B, so as to measure the voltage division of the voltage at the high voltage pin HV through the measuring terminal Vc when the first switch s1 is turned on. Since (R2+R3)>>R1, the voltage division can be regarded as corresponding to the power supply voltage.

存儲單元C2可被配置為連接在測量端子Vc與參考地之間，用於在第一開關s1接通的情況下，存儲經由測量端子Vc測量的分壓，並在第一開關s1斷開的情況下，使測量端子處保持有測量的分壓。在一個實施例中，存儲單元C2可以為第二電容器。 The storage unit C2 can be configured to be connected between the measurement terminal Vc and the reference ground, and is used to store the divided voltage measured by the measurement terminal Vc when the first switch s1 is turned on, and to keep the measured divided voltage at the measurement terminal when the first switch s1 is turned off. In one embodiment, the storage unit C2 can be a second capacitor.

由此，可在測量單元停止對供電電壓進行測量時，也能夠在測量端子Vc處讀取/檢測到供電電壓。從而便於LED晶片對供電電壓的隨時讀取以及相關控制。 Therefore, when the measuring unit stops measuring the supply voltage, the supply voltage can still be read/detected at the measuring terminal Vc. This facilitates the LED chip to read the supply voltage at any time and related control.

如圖4所示，在一個實施例中，第一控制單元211可以為第二開關s2，第二開關s2可根據第一控制信號A接通或斷開。 As shown in FIG. 4 , in one embodiment, the first control unit 211 may be a second switch s2, and the second switch s2 may be turned on or off according to the first control signal A.

此外，為了提高電路210設置的便捷性，電路210還可保留有圖1所示的相應元件，例如，在一個實施例中，電路210還可包括：第二控制單元214，第二控制單元214可被配置為連接在高壓引腳HV與第一控制單元211之間，用於根據供電信號(未示出)開啟或停止供電端Vin經由高壓引腳HV向第一電容器C1(Cvdd)的供電。例如，第二控制單元214可以為圖1所示的開關M1。 In addition, in order to improve the convenience of setting up the circuit 210, the circuit 210 may also retain the corresponding components shown in Figure 1. For example, in one embodiment, the circuit 210 may also include: a second control unit 214, which may be configured to be connected between the high-voltage pin HV and the first control unit 211, and is used to open or stop the power supply terminal Vin through the high-voltage pin HV to the first capacitor C1 (Cvdd) according to a power supply signal (not shown). For example, the second control unit 214 may be the switch M1 shown in Figure 1.

例如，在供電端Vin為外部供電線路Vbus的相應端子Nin的情況下，供電信號可根據LED控制晶片的啟動信號而開啟從供電端Vin向第一電容器C1的供電，並根據LED控制晶片的關閉信號而停止從供電端Vin向第一電容器C1的供電。在供電端Vin為恆流開關M1的汲極D的情況下，供電信號可根據開關M1的斷開信號而開啟從供電端Vin向第一電容器C1的供電，並根據開關M1的接通信號而停止從供電端Vin向第一電容器C1的供電。 For example, when the power supply terminal Vin is the corresponding terminal Nin of the external power supply line Vbus, the power supply signal can start the power supply from the power supply terminal Vin to the first capacitor C1 according to the start signal of the LED control chip, and stop the power supply from the power supply terminal Vin to the first capacitor C1 according to the shutdown signal of the LED control chip. When the power supply terminal Vin is the drain D of the constant current switch M1, the power supply signal can start the power supply from the power supply terminal Vin to the first capacitor C1 according to the disconnection signal of the switch M1, and stop the power supply from the power supply terminal Vin to the first capacitor C1 according to the connection signal of the switch M1.

相應地，第一控制單元211可被配置為連接在第二控制單元214與電源引腳VDD之間，用於在第二控制單元214開啟供電端Vin經由高壓引腳HV向第一電容器C1的供電的情況下，根據第一控制信號A接通或斷開高壓引腳HV與電源引腳VDD之間的連接。 Correspondingly, the first control unit 211 can be configured to be connected between the second control unit 214 and the power pin VDD, and is used to connect or disconnect the connection between the high voltage pin HV and the power pin VDD according to the first control signal A when the second control unit 214 turns on the power supply terminal Vin to supply power to the first capacitor C1 via the high voltage pin HV.

通過以上方式，可在不改變圖1所示的電路110的整體佈局的情況下方便地設置根據本發明的示例性實施例的電路210。 In the above manner, the circuit 210 according to the exemplary embodiment of the present invention can be conveniently set without changing the overall layout of the circuit 110 shown in FIG. 1.

此外，為了生成以上第一控制信號A和第二控制信號B，在一個實施例中，根據本發明的示例性實施例的電路210還可包括：信號生成單元215，信號生成單元215可被配置為生成作為脈寬調變信號的第一控制信號A和第二控制信號B。 In addition, in order to generate the above first control signal A and second control signal B, in one embodiment, the circuit 210 according to the exemplary embodiment of the present invention may also include: a signal generating unit 215, and the signal generating unit 215 may be configured to generate the first control signal A and the second control signal B as pulse width modulation signals.

為了在通過第一控制信號A斷開供電端Vin向第一電容器C1的供電期間，使得第一電容器C1能夠正常地為LED控制晶片200提供相應的工作電力，第一電容器C1兩端的電壓需要保持為基本穩定的電壓，即，第一電容器C1的電壓變化不應太大。因此，在一個實施例中，第一控制信號A可具有預定占空比，該預定占空比可使得在第二開關s2根據第一控制信號A斷開期間，第一電容器C1兩端的電壓的變化量小於第一預定值，例如小於預定百分比。例如，可通過等式△U×C=I×t來設置該占空比，在該等式中，△U可表示電壓變化，C可表示第一電容器C1的電容值，I可第一電容器C1提供的電流，t可表示時間、例如第二開關s2斷開的時間。 In order to enable the first capacitor C1 to normally provide corresponding working power to the LED control chip 200 during the period when the power supply terminal Vin is disconnected from the first control signal A, the voltage across the first capacitor C1 needs to be kept at a substantially stable voltage, that is, the voltage variation of the first capacitor C1 should not be too large. Therefore, in one embodiment, the first control signal A may have a predetermined duty cycle, which may make the variation of the voltage across the first capacitor C1 less than a first predetermined value, such as less than a predetermined percentage, during the period when the second switch s2 is disconnected according to the first control signal A. For example, the duty cycle may be set by the equation ΔU × C = I × t , where ΔU may represent voltage change, C may represent capacitance of the first capacitor C1, I may represent current provided by the first capacitor C1, and t may represent time, such as the time when the second switch s2 is turned off.

在一個實施例中，第一開關s1和第二開關s2可以為具有相同的接通位準的開關(例如，均為NMOS管或均為PMOS管)，此時，第一控制信號A和第二控制信號B可以為反相的信號。 In one embodiment, the first switch s1 and the second switch s2 may be switches with the same on-state level (for example, both are NMOS tubes or both are PMOS tubes), and in this case, the first control signal A and the second control signal B may be inverted signals.

應該理解，第一開關s1和第二開關s2還可以為具有不同的接通位準的開關(例如，一個為NMOS管一個為PMOS管)，此時，第一控制信號A和第二控制信號B可以為相同的信號。 It should be understood that the first switch s1 and the second switch s2 can also be switches with different on-state levels (for example, one is an NMOS tube and the other is a PMOS tube). In this case, the first control signal A and the second control signal B can be the same signal.

圖5是第一開關s1和第二開關s2均為NMOS管、第一控制信號A和第二控制信號B為反相的信號的示例。 Figure 5 is an example where both the first switch s1 and the second switch s2 are NMOS tubes, and the first control signal A and the second control signal B are inverted signals.

如圖5所示，在時間T1之前(圖5的時間T1的左側)，開關M1處於斷開狀態，供電端Vin未向第一電容器C1供電，流經電阻器Rp的電流Ihv可近似為0，高壓引腳HV處的電壓可近似為供電端Vin的供電電壓V1。第一控制信號A可具有低位準(也可以具有高位準)，第二控制信號B可具有高位準，第一開關s1接通，第二開關s2斷開(也可以接通)，此時，在測量端子Vc處測量的分壓vc1可以為vc1=V1×R2/(R2+R3)，這與圖2相同。 As shown in FIG5 , before time T1 (to the left of time T1 in FIG5 ), switch M1 is in the disconnected state, the power supply terminal Vin does not supply power to the first capacitor C1, the current Ihv flowing through the resistor Rp can be approximately 0, and the voltage at the high voltage pin HV can be approximately equal to the power supply voltage V1 of the power supply terminal Vin. The first control signal A can have a low level (or a high level), the second control signal B can have a high level, the first switch s1 is turned on, and the second switch s2 is turned off (or turned on). At this time, the voltage division vc1 measured at the measurement terminal Vc can be vc1=V1×R2/(R2+R3), which is the same as FIG2 .

在時間T1之時以及之後，開關M1處於接通狀態。 At and after time T1, switch M1 is in the on state.

在時間T1至時間T2期間，第一控制信號A可具有高位準，第二控制信號B可具有低位準，第一開關s1可斷開，第二開關s2可接通，流經第一電阻器R1(Rp)的電流Ihv為LED控制晶片的工作電流I1。相應地，電阻器Rp上的電壓降導致高壓引腳HV處的電壓從供電電壓V1下降到電壓V2。此時，測量端子Vc處由於存儲單元C2(第二電容器)而保持有之前測量的分壓vc1。 During the period from time T1 to time T2, the first control signal A may have a high level, the second control signal B may have a low level, the first switch s1 may be disconnected, the second switch s2 may be connected, and the current Ihv flowing through the first resistor R1 (Rp) is the operating current I1 of the LED control chip. Correspondingly, the voltage drop on the resistor Rp causes the voltage at the high voltage pin HV to drop from the supply voltage V1 to the voltage V2. At this time, the measurement terminal Vc maintains the previously measured divided voltage vc1 due to the storage unit C2 (second capacitor).

在時間T2至時間T3期間，第一控制信號A可具有低位準，第二控制信號B可具有高位準，第一開關s1可接通，第二開關s2可斷開，供電端Vin未向第一電容器C1供電，流經電阻器Rp的電流Ihv可近似為0，高壓引腳HV處的電壓可近似為供電端Vin的供電電壓V1。此時，在測量端子Vc處測量的分壓vc1可以為vc1=V1×R2/(R2+R3)。 During the period from time T2 to time T3, the first control signal A may have a low level, the second control signal B may have a high level, the first switch s1 may be turned on, the second switch s2 may be turned off, the power supply terminal Vin does not supply power to the first capacitor C1, the current Ihv flowing through the resistor Rp may be approximately 0, and the voltage at the high voltage pin HV may be approximately the power supply voltage V1 of the power supply terminal Vin. At this time, the divided voltage vc1 measured at the measurement terminal Vc may be vc1=V1×R2/(R2+R3).

由此，可以保障測量端子Vc處測量的分壓vc1準確地與供電電壓對應，從而提高了對供電電壓進行測量的準確性。 Therefore, it can be ensured that the voltage division vc1 measured at the measurement terminal Vc accurately corresponds to the power supply voltage, thereby improving the accuracy of measuring the power supply voltage.

應該理解，圖5(以及圖2)僅是示意性的波形圖，在供電電壓為隨時間變化的電壓(例如，具有類似於正弦波的波形)的情況下，圖5僅示出很短的時間段，因此近似地將供電電壓示出為了恆定電壓，但供電電壓可具有與圖5所示不同的任意波形。 It should be understood that FIG. 5 (and FIG. 2) are only schematic waveform diagrams. When the supply voltage is a voltage that varies with time (for example, having a waveform similar to a sine wave), FIG. 5 only shows a short period of time, and thus approximately shows the supply voltage as a constant voltage. However, the supply voltage may have any waveform different from that shown in FIG. 5.

應該理解，以上示出的各種數值僅是示例，可根據實際需要而將這些值設置為任意不同的值。 It should be understood that the various numerical values shown above are only examples, and these values can be set to any different values according to actual needs.

以上所述的結構框圖中所示的功能塊可以實現為硬體、軟體、韌體或者它們的組合。當以硬體方式實現時，其可以例如是電子電路、特殊應用積體電路(Application Specific Integrated Circuit,ASIC)、適當的韌體、外掛程式、功能卡等。當以軟體方式實現時，本發明的元素是被用於執行所需任務的程式或者程式碼片段。程式或者程式碼片段可以存儲在機器可讀介質中，或者通過載波中攜帶的資料信號在傳輸介質或者通信鏈路上傳送。“機器可讀介質”可以包括能夠存儲或傳輸資訊的任何介質。機器可讀介質的示例包括電子電路、半導體記憶體設備、唯讀記憶體(Read Only Memory,ROM)、快閃記憶體、可擦除ROM(Erasable Read Only Memory,EROM)、磁片、光碟唯讀記憶體(Compact Disc Read-Only Memory,CD-ROM)、光碟、硬碟、光纖介質、射頻(Radio Frequency,RF)鏈路等。程式碼片段可以經由諸如網際網路、內聯網等的電腦網路被下載。 The functional blocks shown in the structural block diagram described above can be implemented as hardware, software, firmware or a combination thereof. When implemented in hardware, it can be, for example, an electronic circuit, an application specific integrated circuit (ASIC), appropriate firmware, a plug-in, a function card, etc. When implemented in software, the elements of the present invention are programs or program code snippets used to perform the required tasks. The programs or program code snippets can be stored in a machine-readable medium, or transmitted on a transmission medium or a communication link via a data signal carried in a carrier. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, read-only memory (ROM), flash memory, erasable ROM (EROM), disks, compact disc read-only memory (CD-ROM), optical discs, hard disks, optical fiber media, radio frequency (RF) links, etc. The code snippet can be downloaded via a computer network such as the Internet, an intranet, etc.

本發明可以以其他的具體形式實現，而不脫離其精神和本質特徵。例如，特定實施例中所描述的演算法可以被修改，而系統體系結構並不脫離本發明的基本精神。因此，當前的實施例在所有方面都被看作是示例性的而非限定性的，本發明的範圍由所附請求項而非上述描述定義，並且，落入請求項的含義和等同物的範圍內的全部改變從而都被包括在本發明的範圍之中。 The present invention can be implemented in other specific forms without departing from its spirit and essential features. For example, the algorithm described in a specific embodiment can be modified, and the system architecture does not deviate from the basic spirit of the present invention. Therefore, the current embodiment is regarded as illustrative rather than restrictive in all aspects, the scope of the present invention is defined by the attached claims rather than the above description, and all changes that fall within the meaning and equivalent scope of the claims are included in the scope of the present invention.

200:LED控制晶片 200:LED control chip

210:電路 210: Circuit

211:第一控制單元 211: First control unit

212:電壓測量單元 212: Voltage measurement unit

C1:第一電容器 C1: First capacitor

Cvdd:儲能器件 Cvdd: energy storage device

GATE:閘極引腳 GATE: Gate pin

HV:高壓引腳 HV: High Voltage Pin

VDD:電源引腳 VDD: power pin

Vin:供電端 Vin: power supply end

Claims

一種用於LED控制晶片的測量供電端的供電電壓的電路，所述供電端用於經由所述LED控制晶片的高壓引腳向連接到所述LED控制晶片的電源引腳的儲能器件供電，以使得所述儲能器件經由所述電源引腳向所述LED控制晶片提供工作電流，其中，所述電路包括： A circuit for measuring the power supply voltage of a power supply terminal of an LED control chip, wherein the power supply terminal is used to supply power to an energy storage device connected to a power supply pin of the LED control chip via a high voltage pin of the LED control chip, so that the energy storage device provides an operating current to the LED control chip via the power supply pin, wherein the circuit comprises:

第一控制單元，被配置為連接在所述高壓引腳與所述電源引腳之間，用於根據第一控制信號接通或斷開所述高壓引腳與所述電源引腳之間的連接；以及 The first control unit is configured to be connected between the high voltage pin and the power pin, and is used to connect or disconnect the connection between the high voltage pin and the power pin according to a first control signal; and

電壓測量單元，被配置為連接在所述高壓引腳與參考地之間，用於根據第二控制信號開啟或停止經由所述高壓引腳對所述供電電壓的測量， The voltage measuring unit is configured to be connected between the high voltage pin and the reference ground, and is used to start or stop the measurement of the power supply voltage via the high voltage pin according to the second control signal.

其中，在所述第一控制單元接通所述高壓引腳與所述電源引腳之間的連接的情況下，所述電壓測量單元停止經由所述高壓引腳對所述供電電壓的測量；在所述第一控制單元斷開所述高壓引腳與所述電源引腳之間的連接的情況下，所述電壓測量單元開啟經由所述高壓引腳對所述供電電壓的測量。 Wherein, when the first control unit connects the connection between the high voltage pin and the power pin, the voltage measurement unit stops measuring the power supply voltage through the high voltage pin; when the first control unit disconnects the connection between the high voltage pin and the power pin, the voltage measurement unit starts measuring the power supply voltage through the high voltage pin.

如請求項1所述的電路，其中，所述供電電壓為隨時間變化的電壓， A circuit as described in claim 1, wherein the supply voltage is a voltage that varies with time,

其中，所述電路還包括： Wherein, the circuit also includes:

限流單元，被配置為連接在所述供電端與所述高壓引腳之間，用於通過限制所述供電端與所述高壓引腳之間的電流大小，來對所述LED控制晶片提供靜電釋放保護，並限制在所述供電電壓變化的過程中從所述LED控制晶片向所述供電端的電流倒流。 The current limiting unit is configured to be connected between the power supply end and the high voltage pin, and is used to provide electrostatic discharge protection for the LED control chip by limiting the current between the power supply end and the high voltage pin, and to limit the current backflow from the LED control chip to the power supply end during the change of the power supply voltage.

如請求項2所述的電路，其中，所述電壓測量單元包括： A circuit as described in claim 2, wherein the voltage measurement unit includes:

分壓單元，被配置為連接在所述高壓引腳與所述參考地之間，用於對所述高壓引腳處的電壓進行分壓；以及 The voltage dividing unit is configured to be connected between the high voltage pin and the reference ground, and is used to divide the voltage at the high voltage pin; and

測量單元，被配置為連接到所述分壓單元，用於根據所述第二控制信號開啟或停止經由測量所述高壓引腳處的電壓的分壓而對所述供電電壓的測量。 The measuring unit is configured to be connected to the voltage dividing unit and is used to start or stop the measurement of the power supply voltage by measuring the voltage division at the high voltage pin according to the second control signal.

如請求項3所述的電路，其中，所述工作電流為隨時間變化的電流， A circuit as described in claim 3, wherein the operating current is a current that varies with time,

其中，在所述第一控制單元接通所述高壓引腳與所述電源引腳之間的連接的情況下，所述限流單元具有所述工作電流，所述測量單元停止對所述供電電壓的測量； Wherein, when the first control unit connects the connection between the high voltage pin and the power pin, the current limiting unit has the working current, and the measuring unit stops measuring the power supply voltage;

在所述第一控制單元斷開所述高壓引腳與所述電源引腳之間的連接的情況下，所述限流單元具有比所述工作電流小至少第一數量級的電流，所述測量單元開啟對所述供電電壓的測量。 When the first control unit disconnects the high voltage pin from the power pin, the current limiting unit has a current that is at least a first order of magnitude smaller than the working current, and the measuring unit starts measuring the power supply voltage.

如請求項4所述的電路，其中，所述分壓單元包括： A circuit as described in claim 4, wherein the voltage divider unit includes:

第一分壓單元，被配置為連接在所述高壓引腳與第一節點之間；以及 A first voltage divider unit is configured to be connected between the high voltage pin and the first node; and

第二分壓單元，被配置為連接在所述第一節點與所述參考地之間， The second voltage divider unit is configured to be connected between the first node and the reference ground.

其中，所述第一節點處的電壓為所述高壓引腳處的電壓的分壓。 Wherein, the voltage at the first node is the divided voltage of the voltage at the high voltage pin.

如請求項5所述的電路，其中，所述測量單元包括： A circuit as described in claim 5, wherein the measuring unit includes:

第一開關，被配置為連接在所述第一節點與測量端子之間，用於根據所述第二控制信號接通或斷開，以在所述第一開關接通的情況下經由所述測量端子來測量所述分壓；以及 A first switch is configured to be connected between the first node and the measuring terminal, and is used to be turned on or off according to the second control signal, so as to measure the divided voltage through the measuring terminal when the first switch is turned on; and

存儲單元，被配置為連接在所述測量端子與所述參考地之間，用於在所述第一開關接通的情況下，存儲經由所述測量端子測量的所述分壓，並在所述第一開關斷開的情況下，使所述測量端子處保持有測量的所述分壓。 The storage unit is configured to be connected between the measuring terminal and the reference ground, and is used to store the divided voltage measured by the measuring terminal when the first switch is turned on, and to keep the measured divided voltage at the measuring terminal when the first switch is turned off.

如請求項6所述的電路，所述電路還包括： The circuit as described in claim 6 further comprises:

第二控制單元，被配置為連接在所述高壓引腳與所述第一控制單元之間，用於根據供電信號開啟或停止所述供電端經由所述高壓引腳向所述儲能器件的供電， The second control unit is configured to be connected between the high-voltage pin and the first control unit, and is used to start or stop the power supply from the power supply end to the energy storage device via the high-voltage pin according to the power supply signal.

其中，所述第一控制單元被配置為連接在所述第二控制單元與所述電源引腳之間，用於在所述第二控制單元開啟所述供電端經由所述高壓引腳向所述儲能器件的供電的情況下，根據所示第一控制信號接通或斷開所述高壓引腳與所述電源引腳之間的連接。 Wherein, the first control unit is configured to be connected between the second control unit and the power pin, and is used to connect or disconnect the connection between the high voltage pin and the power pin according to the first control signal when the second control unit turns on the power supply end to supply power to the energy storage device via the high voltage pin.

如請求項7所述的電路，還包括： The circuit as described in claim 7 also includes:

信號生成單元，被配置為生成作為脈寬調變信號的所述第一控制信號和所述第二控制信號， A signal generating unit is configured to generate the first control signal and the second control signal as pulse width modulated signals,

其中，所述儲能器件為第一電容器，所述第一電容器連接在所述電源引腳與所述參考地之間， Wherein, the energy storage device is a first capacitor, and the first capacitor is connected between the power pin and the reference ground.

其中，所述第一控制單元為第二開關，所述第二開關根據所述第一控制信號接通或斷開， Wherein, the first control unit is a second switch, and the second switch is turned on or off according to the first control signal.

其中，所述第一控制信號具有預定占空比，所述預定占空比使得在所述第二開關根據所述第一控制信號斷開期間，所述第一電容器兩端的電壓的變化量小於第一預定值。 The first control signal has a predetermined duty cycle, and the predetermined duty cycle makes the voltage variation at both ends of the first capacitor less than a first predetermined value during the period when the second switch is disconnected according to the first control signal.

如請求項8所述的電路，其中，所述第一開關和所述第二開關為具有相同的接通位準的開關，所述第一控制信號和所述第二控制信號為反相的信號。 A circuit as described in claim 8, wherein the first switch and the second switch are switches having the same on-state level, and the first control signal and the second control signal are inverted signals.

如請求項8所述的電路，其中，所述限流單元為具有第一阻值的第一電阻器， A circuit as described in claim 8, wherein the current limiting unit is a first resistor having a first resistance value,

其中，所述第一分壓單元為具有第二阻值的第一分壓單元，所述第二分壓單元為具有第三阻值的第二分壓單元，所述第二阻值與所述第三阻值之和比所述第一阻值大至少第二數量級， Wherein, the first voltage dividing unit is a first voltage dividing unit with a second resistance value, the second voltage dividing unit is a second voltage dividing unit with a third resistance value, and the sum of the second resistance value and the third resistance value is at least a second order of magnitude greater than the first resistance value,

其中，所述存儲單元為第二電容器。 Wherein, the storage unit is a second capacitor.

如請求項1至10中任一項所述的電路，其特徵在於，所述LED控制晶片用於LED驅動電路，所述LED驅動電路用於將外部供電線路的電流轉換為恆定電流以為LED供電， The circuit as described in any one of claims 1 to 10 is characterized in that the LED control chip is used in an LED driving circuit, and the LED driving circuit is used to convert the current of an external power supply circuit into a constant current to power the LED,

其中，所述供電端為所述外部供電線路的用於連接到所述LED控制晶片的端子，或者所述供電端為所述LED驅動電路的能夠向所述LED控制晶片提供所述供電電壓的預定端子， Wherein, the power supply end is a terminal of the external power supply circuit used to connect to the LED control chip, or the power supply end is a predetermined terminal of the LED driving circuit capable of providing the power supply voltage to the LED control chip,

其中，所述供電電壓的平均電壓值大於第二電壓值。 Wherein, the average voltage value of the power supply voltage is greater than the second voltage value.

如請求項11所述的電路，其中，所述預定端子為所述LED驅動電路的恆流開關的汲極， A circuit as described in claim 11, wherein the predetermined terminal is the drain of the constant current switch of the LED driving circuit,

其中，所述恆流開關的閘極連接到所述LED控制晶片的恆流控制模組，所述恆流開關的汲極經由二極體連接到所述LED驅動電路的第一輸出端子，並經由電感器連接到所述LED驅動電路的第二輸出端子，所述恆流開關的源極連接到所述參考地， Wherein, the gate of the constant current switch is connected to the constant current control module of the LED control chip, the drain of the constant current switch is connected to the first output terminal of the LED driving circuit via a diode, and is connected to the second output terminal of the LED driving circuit via an inductor, and the source of the constant current switch is connected to the reference ground,

其中，所述外部供電線路連接到所述第一輸出端子，所述第一輸出端子和所述第二輸出端子用於連接所述LED。 Wherein, the external power supply line is connected to the first output terminal, and the first output terminal and the second output terminal are used to connect the LED.

如請求項11所述的電路，其中，所述LED驅動電路具有大於預定值的功率因數。 A circuit as described in claim 11, wherein the LED driving circuit has a power factor greater than a predetermined value.