TWI494024B

TWI494024B - Illumination driving circuit

Info

Publication number: TWI494024B
Application number: TW101145474A
Authority: TW
Inventors: Hangyu Fan
Original assignee: Himax Analogic Inc
Priority date: 2012-12-04
Filing date: 2012-12-04
Publication date: 2015-07-21
Also published as: TW201424456A

Description

照明驅動電路Lighting drive circuit

本揭示內容是有關於一種照明設備，且特別是有關於一種照明設備上的照明驅動電路。The present disclosure relates to a lighting device, and more particularly to an illumination driving circuit on a lighting device.

近年來隨著光電技術發展，業界開發了許多種新穎的照明設備，其中，發光二極體(Light-Emitting Diode,LED)燈管受到廣泛的關注。發光二極體燈管的發光效率和使用壽命均優於傳統的白熾燈管，且在製造上無環保問題，符合節能環保的趨勢。In recent years, with the development of optoelectronic technology, many novel lighting devices have been developed in the industry. Among them, Light-Emitting Diode (LED) lamps have received extensive attention. The luminous efficiency and service life of the LED lamp are superior to those of the traditional incandescent lamp, and there is no environmental protection problem in manufacturing, which is in line with the trend of energy saving and environmental protection.

發光二極體燈管所組成的照明系統最常被人提到的優點即為高效率和較長的使用壽命。在高效率的部份可分成轉換效率和功率因子(Power Factor,PF)二個特性。The most frequently mentioned advantages of lighting systems consisting of light-emitting diode lamps are high efficiency and long service life. In the high efficiency part, it can be divided into two characteristics: conversion efficiency and power factor (PF).

轉換效率所指的是交流電輸入到發光二極體工作輸出，這個過程中有多少輸入功率實際傳遞至發光二極體。若輸入功率傳達至輸出功率的比例愈高，則轉換效率愈高。The conversion efficiency refers to the input of the AC input to the working output of the LED, and how much input power is actually transmitted to the LED during this process. The higher the ratio of input power to output power, the higher the conversion efficiency.

功率因子則是與電力訊號的實功率和虛功率有關，電力公司提供市電電壓為100V~110V或200V~240V，頻率為50~60Hz的三相交流電。一般電阻性負載的瞬時消秏功率為電壓與電流之乘積(P=VI)。然而，純電感性負載或純電容性負載則會造成電流與電壓之間具有90°的相位差，進而造成實功率損失，瞬時消秏功率之計算如下：P =VI cosθ ，其中I代表電流，V代表電壓，θ為電流與電壓之間的相位差角度。The power factor is related to the real power and virtual power of the power signal. The power company provides three-phase AC power with a mains voltage of 100V~110V or 200V~240V and a frequency of 50~60Hz. The instantaneous cancellation power of a typical resistive load is the product of voltage and current (P = VI). However, a purely inductive load or a purely capacitive load will cause a phase difference of 90° between current and voltage, resulting in real power loss. The instantaneous power dissipation is calculated as follows: P = VI cos θ , where I represents current , V represents the voltage, and θ is the phase difference angle between the current and the voltage.

此外，功率因子之計算如下：，其中PF代表功率因子，I代表電流，V代表電壓，θ為電流與電壓之間的相位差角度。In addition, the power factor is calculated as follows: Where PF represents the power factor, I represents the current, V represents the voltage, and θ is the phase difference angle between the current and the voltage.

如上述算式所示，當電流與電壓之間具有90°的相位差時(例如當負載為純電感性負載或純電容性負載)，將使得功率因子大幅下降至0。As shown in the above equation, when there is a phase difference of 90° between the current and the voltage (for example, when the load is a purely inductive load or a purely capacitive load), the power factor will be drastically reduced to zero.

由於發光二極體不是純電阻性負載，且用以驅動發光二極體的驅動電路具有電感與電容之特性，因此將造成輸入電壓和輸入電流的相位差並使得功率因子下降，這將使得電力公司需要輸出更多的功率，才能讓發光二極體達到預設輸出功率。而相位差所產生的虛功率將轉化為不必要的熱能消耗。因此功率因子的提升，將能有效幫助電力公司降低輸出功率，達到實質的節省電力。Since the light-emitting diode is not a purely resistive load, and the driving circuit for driving the light-emitting diode has the characteristics of inductance and capacitance, it will cause a phase difference between the input voltage and the input current and cause a power factor to decrease, which will make the power The company needs to output more power in order for the LED to reach the preset output power. The virtual power generated by the phase difference will be converted into unnecessary heat energy consumption. Therefore, the improvement of the power factor will effectively help the power company to reduce the output power and achieve substantial power savings.

因此，在於實現真正節能的趨勢需求，開發擁有高功率因子之發光二極體照明設備實有必要。Therefore, in order to achieve the trend of true energy saving, it is necessary to develop a light-emitting diode lighting device with a high power factor.

在現今發光二極體照明系統中，驅動電路多半採用降壓式(Buck)的架構，先將交流電整流後提供給驅動電路，一般發光二極體的照明驅動電路分為恆定電壓與恆定電流二種，恆定電壓在設計上較為簡單，但輸出容易受發光二極體的使用特性影響(例如當長時間使用時發光二極體的阻抗將逐步提升，導致操作電流下降)。恆定電壓的操作方式之穩定性不如恆定電流。因此，本揭示文件提出一種恆定電流的驅動架構設計。In today's LED lighting system, most of the drive circuit adopts a Buck structure, which is first rectified and supplied to the drive circuit. The illumination drive circuit of the general LED is divided into constant voltage and constant current. The constant voltage is relatively simple in design, but the output is easily affected by the use characteristics of the light-emitting diode (for example, the impedance of the light-emitting diode will gradually increase when used for a long time, resulting in a drop in operating current). The constant voltage operation is less stable than constant current. Accordingly, the present disclosure proposes a constant current drive architecture design.

為解決上述問題，本揭示文件提出一種照明驅動電路，其採用靴帶式的電感電流監控架構，可透過高壓側降壓式的架構實現，於本案的照明驅動電路中加入感測電阻元件於電感元件的前方，利用電感元件與感測電阻元件之間的節點當作控制模組的虛擬接地端，以控制模組偵測感測電阻元件與開關元件間的節點電壓，便可實現電感電流的監測，藉以精確控制流過電感元件以及後續發光負載的電感電流。In order to solve the above problems, the present disclosure proposes an illumination driving circuit which adopts a bootstrap type inductor current monitoring architecture, which can be realized by a high voltage side buck type architecture, and a sensing resistor element is added to the inductor in the illumination driving circuit of the present case. In front of the component, the node between the inductive component and the sensing resistor is used as the virtual ground of the control module, and the control module detects the node voltage between the sensing resistor component and the switching component to realize the inductor current. Monitoring to precisely control the inductor current flowing through the inductive component and subsequent illuminated loads.

本揭示內容之一態樣是在提供一種照明驅動電路用以驅動發光負載，照明驅動電路包含系統電壓源、開關元件、電感元件、電感電流感測模組以及控制模組。開關元件耦接於該系統電壓源與該發光負載之間。電感元件串連在該開關元件與該發光負載之間。電感電流感測模組包含感測電阻元件串連在該開關元件與該電感元件之間。控制模組耦接至該開關元件之控制端並用以控制開關元件之導通狀態，控制模組之虛擬接地端耦接至感測電阻元件與電感元件之間，控制模組之電感電流感測端耦接至感測電阻元件與開關元件之間，控制模組由電感電流感測端之電壓準位計算流經電感元件之電感電流。One aspect of the present disclosure is to provide an illumination driving circuit for driving an illumination load. The illumination driving circuit includes a system voltage source, a switching element, an inductance element, an inductor current sensing module, and a control module. The switching element is coupled between the system voltage source and the illuminating load. An inductive component is connected in series between the switching component and the illumination load. The inductor current sensing module includes a sensing resistor element connected in series between the switching element and the inductive component. The control module is coupled to the control end of the switching element and is configured to control the conduction state of the switching element. The virtual ground end of the control module is coupled between the sensing resistance element and the inductance element, and the inductor current sensing end of the control module The control module is coupled between the sensing resistor element and the switching component, and the control module calculates the inductor current flowing through the inductor component by the voltage level of the inductor current sensing terminal.

根據本揭示內容之一實施例，系統電壓源包含交流電壓輸入以及整流電路。整流電路耦接於交流電壓輸入與開關元件之間。In accordance with an embodiment of the present disclosure, a system voltage source includes an alternating voltage input and a rectifier circuit. The rectifier circuit is coupled between the AC voltage input and the switching element.

根據本揭示內容之一實施例，其中照明驅動電路更包含輸入電壓感測模組耦接至控制模組之輸入電壓感測端，輸入電壓感測模組包含第一分壓電阻元件、第二分壓電阻元件以及電容元件。第一分壓電阻元件耦接於該系統電壓源與該輸入電壓感測端之間。第二分壓電阻元件耦接於該虛擬接地端與該輸入電壓感測端之間。電容元件耦接於該虛擬接地端與該輸入電壓感測端之間。According to an embodiment of the present disclosure, the illumination driving circuit further includes an input voltage sensing module coupled to the input voltage sensing end of the control module, the input voltage sensing module includes a first voltage dividing resistor component, and a second Voltage divider resistor Components and capacitive components. The first voltage dividing resistor element is coupled between the system voltage source and the input voltage sensing terminal. The second voltage dividing resistor is coupled between the virtual ground and the input voltage sensing terminal. The capacitive element is coupled between the virtual ground and the input voltage sensing end.

根據本揭示內容之一實施例，輸入電壓感測模組用以感測來自該系統電壓源之一輸入電壓並傳送至該控制模組之該輸入電壓感測端，該控制模組據以使該電感電流之相位與該輸入電壓同步。According to an embodiment of the present disclosure, an input voltage sensing module is configured to sense an input voltage from an input voltage source of the system and transmit the input voltage to the control module, and the control module is configured to The phase of the inductor current is synchronized with the input voltage.

根據本揭示內容之一實施例，電感電流依序流經該開關元件、該感測電阻元件、該電感元件以及該發光負載。According to an embodiment of the present disclosure, an inductor current sequentially flows through the switching element, the sensing resistor element, the inductive element, and the illuminating load.

根據本揭示內容之一實施例，控制模組根據該電感電流感測端與該虛擬接地端之間的一電壓差以及該感測電阻元件之一電阻值進而感測該電感電流。According to an embodiment of the present disclosure, the control module senses the inductor current according to a voltage difference between the inductor current sensing terminal and the virtual ground terminal and a resistance value of the sensing resistor element.

根據本揭示內容之一實施例，照明驅動電路更包含電壓啟動模組耦接至該控制模組之啟動感測端，電壓啟動模組包含電阻元件、二極體以及電容元件。電阻元件耦接於該系統電壓源與該啟動感測端之間。二極體耦接於該發光負載與該啟動感測端之間。電容元件耦接於該虛擬接地端與該啟動感測端之間。According to an embodiment of the present disclosure, the illumination driving circuit further includes a voltage starting module coupled to the activation sensing end of the control module, and the voltage starting module includes a resistive element, a diode, and a capacitive element. The resistor element is coupled between the system voltage source and the startup sensing terminal. The diode is coupled between the illuminating load and the startup sensing terminal. The capacitive element is coupled between the virtual ground and the activation sensing end.

根據本揭示內容之一實施例，開關元件初始為關閉時，該系統電壓源之輸入電壓經由該電壓啟動模組之該電阻元件對該電容元件充電，使該啟動感測端之電壓準位提高，直到該啟動感測端之電壓準位滿足該控制模組之一啟動電壓門檻，隨後該控制模組將該關關元件導通。According to an embodiment of the present disclosure, when the switching element is initially turned off, the input voltage of the system voltage source charges the capacitive element through the resistive element of the voltage starting module, so that the voltage level of the starting sensing terminal is increased. Until the voltage level of the startup sensing terminal satisfies a starting voltage threshold of the control module, then the control module turns on the closing component.

根據本揭示內容之一實施例，照明驅動電路更包含一輸出電容元件與該發光負載並連，當該開關元件導通後，該系統電壓源之輸入電壓經由該開關元件對該電感元件及該輸出電容元件進行儲能，直到該電感電流感測端之電壓準位到達該控制模組之一鎖定電壓門檻，隨後該控制模組將該關關元件關閉。According to an embodiment of the present disclosure, the illumination driving circuit further includes a The output capacitor element is connected in parallel with the illuminating load. When the switching element is turned on, the input voltage of the system voltage source stores the inductor element and the output capacitor element through the switching element until the voltage of the inductor current sensing terminal The level reaches a locking voltage threshold of one of the control modules, and then the control module turns off the closing element.

根據本揭示內容之一實施例，當控制模組關閉該關關元件之後，該電感元件對該發光負載釋能並產生該電感電流，該控制模組由該電感電流感測端之電壓準位監控該電感電流，當該電感電流低於一電感電流門檻時該控制模組重新導通該關關元件。According to an embodiment of the present disclosure, after the control module turns off the off component, the inductive component releases the illuminating load and generates the inductor current, and the control module is configured by the voltage level of the inductor current sensing terminal. The inductor current is monitored, and the control module re-energizes the off component when the inductor current is below an inductor current threshold.

請參閱第1圖，其繪示根據本發明之一實施例中一種照明驅動電路100的操作示意圖，照明驅動電路100用以驅動發光負載110，於此實施例中，發光負載110可為發光二極體負載，或其他具相等性的非純電阻性發光負載。FIG. 1 is a schematic diagram showing the operation of an illumination driving circuit 100 according to an embodiment of the present invention. The illumination driving circuit 100 is used to drive the illumination load 110. In this embodiment, the illumination load 110 may be a light-emitting diode. Polar body load, or other equivalent non-pure resistive illuminating load.

照明驅動電路100包含系統電壓源120、開關元件Q1、電感元件L1、電感電流感測模組140以及控制模組160。The illumination driving circuit 100 includes a system voltage source 120, a switching element Q1, an inductance element L1, an inductor current sensing module 140, and a control module 160.

開關元件Q1的輸入端與輸出端耦接於系統電壓源120與發光負載110之間，於此實施例中，開關元件Q1可為一半導體開關。控制模組160耦接至開關元件Q1之控制端(如半導體開關之閘極)並用以控制開關元件Q1之導通狀態。The input end and the output end of the switching element Q1 are coupled between the system voltage source 120 and the illuminating load 110. In this embodiment, the switching element Q1 can be a semiconductor switch. The control module 160 is coupled to the control terminal of the switching element Q1 (such as the gate of the semiconductor switch) and is used to control the conduction state of the switching element Q1.

電感元件L1串連在開關元件Q1與發光負載110之間。The inductance element L1 is connected in series between the switching element Q1 and the light-emitting load 110.

於此實施例中，照明驅動電路100包含電感電流感測模組140，其目的在於直接或間接感測流過電感元件L1的電感電流I_L 。如第1圖中所示，電感電流感測模組140包含感測電阻元件R_S 串連在開關元件Q1與電感元件L1之間。In this embodiment, the illumination driving circuit 100 includes an inductor current sensing module 140 for directly or indirectly sensing the inductor current I _L flowing through the inductive component L1. As shown in FIG. 1, the inductor current sensing module 140 includes a sensing resistor element R _S connected in series between the switching element Q1 and the inductive element L1.

其中，控制模組160之電感電流感測端CS耦接至感測電阻元件R_S 與開關元件Q1之間的第一節點N1。而控制模組160之虛擬接地端GND耦接至感測電阻元件R_S 與電感元件L1之間的第二節點N2。上述連接方式即為本揭示文件所提出的靴帶式的電感電流監控架構。The inductor current sensing terminal CS of the control module 160 is coupled to the first node N1 between the sensing resistor element R _S and the switching element Q1. The virtual ground GND of the control module 160 is coupled to the second node N2 between the sensing resistive element R _S and the inductive component L1. The above connection method is the bootstrap type inductor current monitoring architecture proposed in the present disclosure.

控制模組可得知電感電流感測端CS之電壓準位(即第一節點N1的電壓)與虛擬接地端GND之電壓準位(即第二節點N2的電壓)其間的電壓差。由於感測電阻元件R_S 在設計中具有已知的固定電阻值，控制模組可由N1與N2的電壓差計算流經電感元件L1之電感電流I_L 。The control module can know the voltage difference between the voltage level of the inductor current sensing terminal CS (ie, the voltage of the first node N1) and the voltage level of the virtual ground GND (ie, the voltage of the second node N2). Since the sense resistor element R _S has a known fixed resistance value in the design, the control module can calculate the inductor current I _L flowing through the inductor element L1 from the voltage difference between N1 and N2.

於此例中，控制模組160係將感測電阻元件R_S 與電感元件L1之間的第二節點N2之電壓準位作為控制模組160所採用的接地電位。也就是說，控制模組160藉由偵測電感電流感測端CS之電壓準位，便可得知流經電感元件L1之電感電流I_L 。須補充的是，於此例中，電感電流I_L 依序流經開關元件Q1、感測電阻元件R_S 、電感元件L1以及發光負載110。因此，控制模組160可由電感電流I_L 大致感測得知流經發光負載110的操作電流。在實際應用中，照明驅動電路100可進一步包含其他元件。In this example, the control module 160 uses the voltage level of the second node N2 between the sensing resistance element R _S and the inductance element L1 as the ground potential used by the control module 160. That is to say, the control module 160 can know the inductor current I _L flowing through the inductor element L1 by detecting the voltage level of the inductor current sensing terminal CS. It should be added that, in this example, the inductor current I _L sequentially flows through the switching element Q1, the sensing resistance element R _S , the inductance element L1 , and the illuminating load 110 . Therefore, the control module 160 can substantially sense the operating current flowing through the lighting load 110 from the inductor current I _L . In practical applications, the illumination driving circuit 100 may further include other components.

請一併參閱第2圖以及第3圖，第2圖根據繪示根據本發明之一實施例中一種照明驅動電路100的功能方塊示意圖，第3圖繪示根據第2圖之實施例中照明驅動電路100其電路架構圖。第3圖係照明驅動電路100的其中一種電路實施架構，但本揭示文件並不以僅限於此種電路實施方式。Please refer to Figure 2 and Figure 3 together. Figure 2 is based on the drawing. A functional block diagram of an illumination driving circuit 100 according to an embodiment of the present invention, and FIG. 3 is a circuit diagram of the illumination driving circuit 100 according to the embodiment of FIG. 2. FIG. 3 is one of the circuit implementation architectures of illumination driver circuit 100, but the disclosure is not limited to such circuit implementations.

如第2圖所示之實施例中，照明驅動電路100更包含輸入電壓感測模組180以及電壓啟動模組190。輸入電壓感測模組180與電壓啟動模組190分別電性連接至系統電壓源120與開關元件Q1之間的輸入節點，用以感測系統電壓源120產生的輸入訊號。如第3圖所示，照明驅動電路100更包含輸出電容元件C_OUT 與發光負載110並連。In the embodiment shown in FIG. 2 , the illumination driving circuit 100 further includes an input voltage sensing module 180 and a voltage starting module 190 . The input voltage sensing module 180 and the voltage starting module 190 are electrically connected to the input node between the system voltage source 120 and the switching element Q1, respectively, for sensing the input signal generated by the system voltage source 120. As shown in FIG. 3, the illumination driving circuit 100 further includes an output capacitive element C _OUT connected in parallel with the illuminating load 110.

如第3圖所示，系統電壓源120可包含交流電壓輸入VAC以及整流電路(於此實施例中為橋式整流器BD)。橋式整流器BD耦接於交流電壓輸入VAC與開關元件Q1之間。於部份實施例中，交流電壓輸入VAC可為外部的市電插座。As shown in FIG. 3, system voltage source 120 can include an alternating voltage input VAC and a rectifier circuit (bridge rectifier BD in this embodiment). The bridge rectifier BD is coupled between the AC voltage input VAC and the switching element Q1. In some embodiments, the AC voltage input VAC can be an external mains outlet.

輸入電壓感測模組180耦接至控制模組160之輸入電壓感測端VS。如第3圖所示，輸入電壓感測模組180包含第一分壓電阻元件R_P1 、第二分壓電阻元件R_P2 以及電容元件C_P1 。第一分壓電阻元件R_P1 耦接於系統電壓源120與輸入電壓感測端VS之間。第二分壓電阻元件R_P2 耦接於虛擬接地端GND與輸入電壓感測端VS之間。電容元件C_P1 耦接於虛擬接地端GND與輸入電壓感測端VS之間。The input voltage sensing module 180 is coupled to the input voltage sensing terminal VS of the control module 160. As shown in FIG. 3, the input voltage sensing module 180 includes a first voltage dividing resistor element R _P1 , a second voltage dividing resistor element R _{P2 ,} and a capacitor element C _P1 . The first voltage dividing resistor element R _{P1 is} coupled between the system voltage source 120 and the input voltage sensing terminal VS. The second voltage dividing resistor R _{P2 is} coupled between the virtual ground GND and the input voltage sensing terminal VS. The capacitive component C _{P1 is} coupled between the virtual ground GND and the input voltage sensing terminal VS.

輸入電壓感測模組180用以感測來自系統電壓源120之輸入電壓並傳送至控制模組160之輸入電壓感測端VS。控制模組160根據輸入電壓感測端VS之電壓準位(代表系統電壓源120的輸入電壓)與電感電流感測端CS之電壓準位(代表系統電壓源120的輸入電流)得知來自系統電壓源120的輸入電壓與電流之間的關係。控制模組160可根述上述關係調整開關元件Q1之導通狀態(如導通頻率、頻寬、相位等)使電感電流I_L 之相位與輸入電壓同步。The input voltage sensing module 180 is configured to sense an input voltage from the system voltage source 120 and transmit it to the input voltage sensing terminal VS of the control module 160. The control module 160 learns from the system according to the voltage level of the input voltage sensing terminal VS (representing the input voltage of the system voltage source 120) and the voltage level of the inductor current sensing terminal CS (representing the input current of the system voltage source 120). The relationship between the input voltage and current of voltage source 120. The control module 160 can adjust the conduction state (such as the on frequency, the bandwidth, the phase, and the like) of the switching element Q1 according to the relationship described above to synchronize the phase of the inductor current I _L with the input voltage.

請一併參閱第4圖，其繪示於一實施例中照明驅動電路100之訊號時序示意圖。如第4圖所示，上方的波形為輸入電壓感測端VS上的電壓準位(即系統電壓源120經過橋式整流器BD後之輸入電壓)。控制模組160調整開關元件Q1之導通狀態使電感電流I_L 之相位與輸入電壓(參見第4圖中的VS波形)同步。Please refer to FIG. 4, which is a timing diagram of the signal of the illumination driving circuit 100 in an embodiment. As shown in FIG. 4, the upper waveform is the voltage level on the input voltage sensing terminal VS (ie, the input voltage of the system voltage source 120 after passing through the bridge rectifier BD). The control module 160 adjusts the conduction state of the switching element Q1 to synchronize the phase of the inductor current I _L with the input voltage (see the VS waveform in FIG. 4).

此外，如第3圖所示，照明驅動電路100之電壓啟動模組190耦接至控制模組160之啟動感測端VIN，電壓啟動模組190包含電阻元件R_IN 、二極體D₂ 以及電容元件C_IN 。電阻元件R_IN 耦接於系統電壓源120與啟動感測端VIN之間。二極體D₂ 耦接於發光負載110與啟動感測端VIN之間。電容元件C_IN 耦接於虛擬接地端GND與啟動感測端VIN之間。電壓啟動模組190用以在初始啟動時驅動控制模組160進入正常工作狀態。In addition, as shown in FIG. 3, the voltage starting module 190 of the illumination driving circuit 100 is coupled to the activation sensing terminal VIN of the control module 160, and the voltage starting module 190 includes a resistive element R _IN , a diode D _{2 ,} and Capacitor element C _IN . The resistive element R _{IN is} coupled between the system voltage source 120 and the startup sense terminal VIN. The diode D _{2 is} coupled between the light-emitting load 110 and the start sensing terminal VIN. The capacitive element C _{IN is} coupled between the virtual ground GND and the start sensing terminal VIN. The voltage starting module 190 is used to drive the control module 160 into a normal working state during initial startup.

以下段落以一操作實施例簡單說明本揭示文件中照明驅動電路100的作動方式，但本發明並不以此為限。於一初始狀態(如發光負載110尚未點亮時)下，開關元件Q1初始為關閉。系統電壓源120啟動並開始提供輸入電壓。系統電壓源120之輸入電壓經由電壓啟動模組190之電阻元件R_IN 對電容元件C_IN 充電，使啟動感測端VIN之電壓準位提高，直到啟動感測端VIN之電壓準位滿足控制模組160之啟動電壓門檻。當啟動感測端VIN之電壓準位滿足控制模組160之啟動電壓門檻，控制模組160將關關元件Q1導通。藉此，完成照明驅動電路100的初始啟動。The following paragraphs briefly describe the manner of operation of the illumination driving circuit 100 in the present disclosure with an operational embodiment, but the invention is not limited thereto. In an initial state (e.g., when the lighting load 110 has not been illuminated), the switching element Q1 is initially turned off. System voltage source 120 is activated and begins to provide an input voltage. The input voltage of the system voltage source 120 charges the capacitive element C _IN via the resistive element R _IN of the voltage starting module 190, so that the voltage level of the sense sensing terminal VIN is increased until the voltage level of the sensing terminal VIN is met to satisfy the control mode. The starting voltage threshold for group 160. When the voltage level of the sense terminal VIN is met to satisfy the threshold voltage of the control module 160, the control module 160 turns on the off component Q1. Thereby, the initial startup of the illumination driving circuit 100 is completed.

當開關元件Q1導通之後，系統電壓源120之輸入電壓經由開關元件Q1對電感元件L1及輸出電容元件C_OUT 進行儲能，使電感電流感測端CS之電壓準位逐漸升高，直到電感電流感測端CS之電壓準位到達控制模組160之鎖定電壓門檻。當電感電流感測端CS之電壓準位到達控制模組160之鎖定電壓門檻，控制模組160便將關關元件Q1關閉。After the switching element Q1 is turned on, the input voltage of the system voltage source 120 stores the inductor element L1 and the output capacitor element C _OUT via the switching element Q1, so that the voltage level of the inductor current sensing terminal CS gradually rises until the inductor current The voltage level of the influenza terminal CS reaches the threshold voltage threshold of the control module 160. When the voltage level of the inductor current sensing terminal CS reaches the locking voltage threshold of the control module 160, the control module 160 turns off the closing component Q1.

當控制模組160關閉關關元件Q1之後，電感元件L1對發光負載110釋能並產生電感電流I_L ，控制模組160由電感電流感測端CS之電壓準位(即感測電阻元件R_S 與開關元件Q1之間的第一節點N1電位)監控電感電流I_L 。於此同時，輸入電壓感測模組180可進一步將其所得到電壓準位(代表輸入電壓)提供給控制模組160的輸入電壓感測端VS，由控制模組160對電感電流I_L 與輸入電壓進行相位同步(如第4圖所示)。After the control module 160 turns off the closing component Q1, the inductor component L1 releases the light-emitting load 110 and generates an inductor current I _L , and the control module 160 is connected to the voltage level of the inductor current sensing terminal CS (ie, the sensing resistor component R). The first node N1 potential between _S and switching element Q1) monitors the inductor current I _L . At the same time, the input voltage sensing module 180 can further provide the obtained voltage level (representing the input voltage) to the input voltage sensing terminal VS of the control module 160, and the control module 160 pairs the inductor current I _L and The input voltage is phase synchronized (as shown in Figure 4).

當電感電流I_L 低於電感電流門檻時(例如電感電流感測端CS之電壓準位低於一門檻電壓值時)，控制模組160重新導通關關元件Q1，藉此循環操作，以提供穩定驅動訊號至發光負載110，其中流過發光負載110的平均電流趨近於正電平之弦波波形(如第4圖中的平均電流Iavg)。When the inductor current I _{L is} lower than the inductor current threshold (for example, when the voltage level of the inductor current sensing terminal CS is lower than a threshold voltage value), the control module 160 re-turns the off component Q1, thereby circulating operation to provide The drive signal is stabilized to the illuminating load 110, wherein the average current flowing through the illuminating load 110 approaches a sinusoidal waveform of a positive level (such as the average current Iavg in FIG. 4).

綜上所述，本揭示文件提出一種照明驅動電路，其採用靴帶式的電感電流監控架構，可透過高壓側降壓式的架構實現，於本案的照明驅動電路中加入感測電阻元件於電感元件的前方，利用電感元件與感測電阻元件之間的節點當作控制模組的虛擬接地端，以控制模組偵測感測電阻元件與開關元件間的節點電壓，便可實現電感電流的監測，藉以精確控制流過電感元件以及後續發光負載的電感電流。In summary, the present disclosure proposes an illumination driving circuit that adopts a bootstrap type inductor current monitoring architecture, which can be realized by a high voltage side buck architecture, and a sensing resistor component is added to the inductor in the illumination driving circuit of the present invention. In front of the component, the node between the inductive component and the sensing resistor is used as the virtual ground of the control module, and the control module detects the node voltage between the sensing resistor component and the switching component to realize the inductor current. Monitoring to precisely control the inductor current flowing through the inductive component and subsequent illuminated loads.

雖然本揭示內容已以實施方式揭露如上，然其並非用以限定本揭示內容，任何熟習此技藝者，在不脫離本揭示內容之精神和範圍內，當可作各種之更動與潤飾，因此本揭示內容之保護範圍當視後附之申請專利範圍所界定者為準。The present disclosure has been disclosed in the above embodiments, but it is not intended to limit the disclosure, and any person skilled in the art can make various changes and refinements without departing from the spirit and scope of the disclosure. The scope of protection of the disclosure is subject to the definition of the scope of the patent application.

100‧‧‧照明驅動電路100‧‧‧Lighting drive circuit

110‧‧‧發光負載110‧‧‧Lighting load

120‧‧‧系統電壓源120‧‧‧System voltage source

140‧‧‧電感電流感測模組140‧‧‧Inductance Current Sensing Module

160‧‧‧控制模組160‧‧‧Control Module

180‧‧‧輸入電壓感測模組180‧‧‧Input voltage sensing module

190‧‧‧電壓啟動模組190‧‧‧Voltage Starter Module

Q1‧‧‧開關元件Q1‧‧‧Switching elements

L1‧‧‧電感元件L1‧‧‧Inductance components

R_S ‧‧‧感測電阻元件R _S ‧‧‧Sensor resistance element

為讓本揭示內容之上述和其他目的、特徵、優點與實施例能更明顯易懂，所附圖式之說明如下：第1圖繪示根據本發明之一實施例中一種照明驅動電路的操作示意圖；第2圖根據繪示根據本發明之一實施例中一種照明驅動電路的功能方塊示意圖；第3圖繪示根據第2圖之實施例中照明驅動電路之電路架構圖；以及第4圖繪示根據本發明之一實施例中照明驅動電路之訊號時序示意圖。The above and other objects, features, advantages and embodiments of the present disclosure will become more apparent and understood. The description of the drawings is as follows: FIG. 1 illustrates an operation of an illumination driving circuit according to an embodiment of the present invention. 2 is a functional block diagram showing an illumination driving circuit according to an embodiment of the present invention; FIG. 3 is a circuit diagram of a lighting driving circuit according to an embodiment of FIG. 2; and FIG. Illustrating an illumination driving circuit according to an embodiment of the present invention Signal timing diagram.

100‧‧‧照明驅動電路100‧‧‧Lighting drive circuit

110‧‧‧發光負載110‧‧‧Lighting load

120‧‧‧系統電壓源120‧‧‧System voltage source

160‧‧‧控制模組160‧‧‧Control Module

180‧‧‧輸入電壓感測模組180‧‧‧Input voltage sensing module

190‧‧‧電壓啟動模組190‧‧‧Voltage Starter Module

Q1‧‧‧開關元件Q1‧‧‧Switching elements

L1‧‧‧電感元件L1‧‧‧Inductance components

Claims

一種照明驅動電路，用以驅動一發光負載，該照明驅動電路包含：一系統電壓源；一開關元件，耦接於該系統電壓源與該發光負載之間；一電感元件，串連在該開關元件與該發光負載之間；一電感電流感測模組，包含一感測電阻元件串連在該開關元件與該電感元件之間；以及一控制模組，耦接至該開關元件之一控制端並用以控制該開關元件之導通狀態，該控制模組之一虛擬接地端耦接至該感測電阻元件與該電感元件之間，該控制模組之一電感電流感測端耦接至該感測電阻元件與該開關元件之間，該控制模組由該電感電流感測端之電壓準位計算流經該電感元件之一電感電流，其中該控制模組之一輸入電壓感測端接收來自該系統電壓源之一輸入電壓，該控制模組根據該輸入電壓使該電感電流之相位與該輸入電壓的相位同步。 An illumination driving circuit for driving an illumination load, the illumination driving circuit comprising: a system voltage source; a switching element coupled between the system voltage source and the illumination load; and an inductive component serially connected to the switch Between the component and the illuminating load; an inductor current sensing module comprising a sensing resistor element connected in series between the switching component and the inductive component; and a control module coupled to the one of the switching component And the one end of the control module is coupled to the sensing resistor element and the inductive component, and the inductor current sensing end of the control module is coupled to the Between the sensing resistor element and the switching component, the control module calculates an inductor current flowing through the inductor component from a voltage level of the inductor current sensing terminal, wherein the input voltage sensing terminal of the control module receives An input voltage from one of the system voltage sources, the control module synchronizing the phase of the inductor current with the phase of the input voltage according to the input voltage.

如請求項1所述之照明驅動電路，其中該系統電壓源包含：一交流電壓輸入；以及一整流電路，耦接於該交流電壓輸入與該開關元件之間。 The illumination driving circuit of claim 1, wherein the system voltage source comprises: an alternating voltage input; and a rectifying circuit coupled between the alternating voltage input and the switching element.

如請求項1所述之照明驅動電路，其中該照明驅動電路更包含一輸入電壓感測模組，耦接至該控制模組之該輸入電壓感測端，該輸入電壓感測模組包含：一第一分壓電阻元件，耦接於該系統電壓源與該輸入電壓感測端之間；一第二分壓電阻元件，耦接於該虛擬接地端與該輸入電壓感測端之間；以及一電容元件，耦接於該虛擬接地端與該輸入電壓感測端之間。 The illumination driving circuit of claim 1, wherein the illumination driving circuit further comprises an input voltage sensing module coupled to the input voltage sensing end of the control module, the input voltage sensing module comprising: a first voltage-dividing resistor is coupled between the voltage source of the system and the input voltage sensing terminal; a second voltage-dividing resistor is coupled between the virtual ground and the input voltage sensing terminal; And a capacitive component coupled between the virtual ground and the input voltage sensing terminal.

如請求項3所述之照明驅動電路，其中該輸入電壓感測模組用以感測來自該系統電壓源之該輸入電壓並傳送至該控制模組之該輸入電壓感測端，該控制模組根據該輸入電壓感測端上的電壓準位與該電感電流感測端的電壓準位調整該開關元件之該導通狀態，使該電感電流之相位與該輸入電壓的相位同步，其中該導通狀態包括導通頻率。 The illumination driving circuit of claim 3, wherein the input voltage sensing module is configured to sense the input voltage from the voltage source of the system and transmit the input voltage to the input voltage sensing end of the control module, the control mode The group adjusts the conduction state of the switching element according to the voltage level on the sensing terminal of the input voltage and the voltage level of the sensing current sensing terminal, so that the phase of the inductor current is synchronized with the phase of the input voltage, wherein the conducting state Includes the turn-on frequency.

如請求項1所述之照明驅動電路，其中該電感電流依序流經該開關元件、該感測電阻元件、該電感元件以及該發光負載。 The illumination driving circuit of claim 1, wherein the inductor current sequentially flows through the switching element, the sensing resistor element, the inductive element, and the illuminating load.

如請求項5所述之照明驅動電路，其中該控制模組根據該電感電流感測端與該虛擬接地端之間的一電壓差以及該感測電阻元件之一電阻值進而感測該電感電流。 The illumination driving circuit of claim 5, wherein the control module senses the inductor current according to a voltage difference between the inductor current sensing terminal and the virtual ground terminal and a resistance value of the sensing resistor component .

如請求項1所述之照明驅動電路，其中該照明驅動電路更包含一電壓啟動模組，耦接至該控制模組之一啟動感測端，該電壓啟動模組包含：一電阻元件，耦接於該系統電壓源與該啟動感測端之間；一二極體，耦接於該發光負載與該啟動感測端之間；以及一電容元件，耦接於該虛擬接地端與該啟動感測端之間。 The lighting driving circuit of claim 1, wherein the lighting driving circuit further comprises a voltage starting module coupled to one of the control module to activate the sensing end, the voltage starting module comprising: a resistive component, coupled Connected between the voltage source of the system and the startup sensing terminal; a diode coupled between the illumination load and the startup sensing terminal; and a capacitive component coupled to the virtual ground and the startup Between the sensing ends.

如請求項7所述之照明驅動電路，其中當該開關元件初始為關閉時，該系統電壓源之輸入電壓經由該電壓啟動模組之該電阻元件對該電容元件充電，使該啟動感測端之電壓準位提高，直到該啟動感測端之電壓準位滿足該控制模組之一啟動電壓門檻，隨後該控制模組將該關關元件導通。 The illumination driving circuit of claim 7, wherein when the switching element is initially turned off, the input voltage of the system voltage source charges the capacitive element via the resistive element of the voltage starting module, so that the starting sensing end The voltage level is increased until the voltage level of the start sensing terminal satisfies a starting voltage threshold of the control module, and then the control module turns on the closing element.

如請求項8所述之照明驅動電路，其中該照明驅動電路更包含一輸出電容元件與該發光負載並連，當該開關元件導通後，該系統電壓源之輸入電壓經由該開關元件對該電感元件及該輸出電容元件進行儲能，直到該電感電流感測端之電壓準位到達該控制模組之一鎖定電壓門檻，隨後該控制模組將該關關元件關閉。 The illumination driving circuit of claim 8, wherein the illumination driving circuit further comprises an output capacitive component connected in parallel with the illuminating load, wherein when the switching component is turned on, an input voltage of the system voltage source is connected to the inductor via the switching component The component and the output capacitive component are stored until the voltage level of the inductor current sensing terminal reaches a locking voltage threshold of the control module, and then the control module turns off the closing component.

如請求項9所述之照明驅動電路，其中該控制模組關閉該關關元件之後，該電感元件對該發光負載釋能並產生該電感電流，該控制模組由該電感電流感測端之電壓準位監控該電感電流，當該電感電流低於一電感電流門檻時該控制模組重新導通該關關元件。 The illumination driving circuit of claim 9, wherein the control mode After the group closes the off component, the inductive component releases the illuminating load and generates the inductor current, and the control module monitors the inductor current by the voltage level of the inductor current sensing terminal, when the inductor current is lower than one The control module re-energizes the shut-off element when the inductor current threshold is reached.