TWM457343U - Circuit for inhibiting switching power supply outputting overshoot voltage at startup - Google Patents
Circuit for inhibiting switching power supply outputting overshoot voltage at startup Download PDFInfo
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- TWM457343U TWM457343U TW101222454U TW101222454U TWM457343U TW M457343 U TWM457343 U TW M457343U TW 101222454 U TW101222454 U TW 101222454U TW 101222454 U TW101222454 U TW 101222454U TW M457343 U TWM457343 U TW M457343U
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
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Abstract
Description
本創作是有關於一種開關電源(switching power supply)，且特別是有關於一種抑制開關電源在開機時輸出過衝(overshoot)電壓的電路。 The present invention relates to a switching power supply, and more particularly to a circuit for suppressing an output of an overshoot voltage when a switching power supply is turned on.
請參見圖1，圖1為現有液晶顯示產品交流轉直流(AC-DC)開關電源的一實施例電路圖。該開關電源架構為返馳式(flyback)架構，有兩個輸出電壓Vout1和Vout2。第一輸出電壓Vout1輸出一典型值例如為5V的直流電作為液晶顯示產品的主機板電路的供電電壓，而第二輸出電壓Vout2輸出一典型值例如為16V的直流電作為液晶顯示產品的發光二極體(LED)燈管驅動電路的輸入供電電壓。該輸出電壓Vout1通過電阻器R8和R9進行電壓取樣後提供給三端並聯穩壓器IC3，例如TL431的參考端R，而該輸出電壓Vout2通過電阻器R8和R10進行電壓取樣後也提供給三端並聯穩壓器IC3，例如TL431的參考端R。TL431的參考端R所得到的取樣電壓與TL431內部一電壓為2.5V的參考電壓進行比較後，TL431內部電晶體的輸出端將輸出一電流Ika，使得光耦合器IC2輸入端的發光二極體得到一電流If=Ika-Ir14=Ika-Vf/R14，其中，Ir14為流過電阻器R14的電流值，Vf為光耦合器IC2的發光二極體的正向導通電壓(約為1V左右)，R14為電阻器R14的電阻值。 Please refer to FIG. 1. FIG. 1 is a circuit diagram of an embodiment of an alternating current to direct current (AC-DC) switching power supply of a conventional liquid crystal display product. The switching power supply architecture is a flyback architecture with two output voltages, Vout1 and Vout2. The first output voltage Vout1 outputs a typical value of, for example, 5V DC as the power supply voltage of the motherboard circuit of the liquid crystal display product, and the second output voltage Vout2 outputs a typical value of, for example, 16V DC as the LED of the liquid crystal display product. (LED) The input supply voltage of the lamp drive circuit. The output voltage Vout1 is voltage sampled by the resistors R8 and R9 and then supplied to the three-terminal shunt regulator IC3, such as the reference terminal R of the TL431, and the output voltage Vout2 is also supplied to the voltage after voltage sampling by the resistors R8 and R10. The terminal shunt regulator IC3, such as the reference terminal R of the TL431. After the sampling voltage obtained by the reference terminal R of the TL431 is compared with a reference voltage of 2.5V inside the TL431, the output of the internal transistor of the TL431 will output a current Ika, so that the LED of the input end of the optocoupler IC2 is obtained. A current If=Ika-Ir14=Ika-Vf/R14, where Ir14 is the current value flowing through the resistor R14, and Vf is the forward voltage of the light-emitting diode of the optocoupler IC2 (about 1V). R14 is the resistance value of the resistor R14.
光耦合器IC2的發光二極體的電流If大小決定光耦合器IC2輸出端的光 電晶體的集極與射極流過電流Ic的大小，即Ic=If×CTR，其中，CTR為光耦合器IC2的電流轉移比。該電流Ic的大小直接影響到控制晶片IC1的回饋端FB的電壓大小，而回饋端FB的電壓大小將直接影響到控制晶片IC1的輸出端GATE輸出的脈寬調變(PWM)信號的工作週期(duty)大小，並通過NMOS電晶體Q1控制變壓器Tr1的能量傳輸，從而控制了輸出電壓Vout1和Vout2以達到基本恆定的直流電壓。 The current If of the light-emitting diode of the photocoupler IC2 determines the light output at the output of the photocoupler IC2. The collector and the emitter of the transistor flow through the current Ic, that is, Ic = If × CTR, where CTR is the current transfer ratio of the photocoupler IC2. The magnitude of the current Ic directly affects the voltage of the feedback terminal FB of the control chip IC1, and the voltage level of the feedback terminal FB directly affects the duty cycle of the pulse width modulation (PWM) signal outputted by the output terminal GATE of the control chip IC1. (duty) size, and control the energy transfer of the transformer Tr1 through the NMOS transistor Q1, thereby controlling the output voltages Vout1 and Vout2 to achieve a substantially constant DC voltage.
圖1採用了輸出電壓Vout1和Vout2雙回饋控制方式。輸出電壓Vout1為提供給主機板電路的供電電壓，需要較為精準，故目前一般輸出電壓Vout1規格都控制在誤差±5%以內，例如5V×(1±5%)=4.75V~5.25V。輸出電壓Vout2一般只提供給LED燈管的直流轉直流(DC-DC)升壓驅動電路供電，目前該DC-DC升壓驅動電路對輸入電壓範圍要求較寬鬆，例如輸出30V以上的DC-DC升壓驅動電路的輸入電壓一般落在12V~23V左右都可以。由於輸出電壓Vout1需要較為精準，故一般回饋電路會將輸出電壓Vout1設定為主回饋電路，而輸出電壓Vout2設定為次回饋電路，即該開關電源基本上是通過偵測輸出電壓Vout1的波動來決定控制晶片IC1的輸出端GATE輸出的PWM信號的工作週期大小，從而控制變壓器Tr1的能量傳輸。 Figure 1 uses the output voltage Vout1 and Vout2 double feedback control mode. The output voltage Vout1 is the supply voltage supplied to the motherboard circuit, which needs to be more accurate. Therefore, the current general output voltage Vout1 specifications are controlled within ±5% of the error, for example, 5V × (1 ± 5%) = 4.75V ~ 5.25V. The output voltage Vout2 is generally only supplied to the DC-DC boost drive circuit of the LED tube. Currently, the DC-DC boost drive circuit requires looser input voltage range, for example, a DC-DC output of 30V or more. The input voltage of the boost drive circuit generally falls between 12V and 23V. Since the output voltage Vout1 needs to be more precise, the general feedback circuit sets the output voltage Vout1 as the main feedback circuit, and the output voltage Vout2 is set as the secondary feedback circuit, that is, the switching power supply is basically determined by detecting the fluctuation of the output voltage Vout1. The duty cycle of the PWM signal outputted by the output terminal GATE of the chip IC1 is controlled, thereby controlling the energy transfer of the transformer Tr1.
請參見圖2，圖2為現有液晶顯示產品AC-DC開關電源的另一實施例電路圖，與圖1所示開關電源相比，圖2所示開關電源改採用了輸出電壓Vout1單回饋控制方式。該開關電源通常使用在多功能的液晶顯示產品，除了提供給主機板電路工作外還要提供給通用串列匯流排(USB)、音訊等電路供電，使得輸出電壓Vout1負載較大。在液晶顯示產品開機，即該開關電源輸入市用交流電時，於輸出電壓Vout1吃重載而輸出電壓Vout2未吃載時，若採用圖1的雙回饋電路容易產生輸出電壓Vout1因輸出電壓Vout2較大幅度上升而被拉低，嚴重時會使輸出電壓Vout1例如由5V瞬間掉到4V以下， 使得主機板的微控制器(MCU)及影像縮放器(scaler)等晶片無法正常工作；若採用圖2的單回饋電路，此時輸出電壓Vout2主要是依靠假負載電路(由齊納二極體ZD1、電晶體Q2及電阻器R11~R13組成)來做鉗位。 Referring to FIG. 2, FIG. 2 is a circuit diagram of another embodiment of a conventional liquid crystal display product AC-DC switching power supply. Compared with the switching power supply shown in FIG. 1, the switching power supply shown in FIG. 2 adopts a single feedback control mode of output voltage Vout1. . The switching power supply is usually used in a multi-functional liquid crystal display product, and in addition to providing work for the motherboard circuit, it is also provided with power supply to a universal serial bus (USB), audio, and the like, so that the output voltage Vout1 is heavily loaded. When the liquid crystal display product is turned on, that is, when the switching power supply is input to the commercial alternating current, when the output voltage Vout1 is heavily loaded and the output voltage Vout2 is not loaded, if the double feedback circuit of FIG. 1 is used, the output voltage Vout1 is easily generated due to the output voltage Vout2. If it rises sharply, it will be pulled down. In severe cases, the output voltage Vout1 will fall to 4V or less, for example, from 5V. The chip such as the microcontroller (MCU) and the image scaler of the motherboard cannot be operated normally; if the single feedback circuit of FIG. 2 is adopted, the output voltage Vout2 mainly depends on the dummy load circuit (by the Zener diode) ZD1, transistor Q2 and resistors R11~R13 are used to clamp.
針對待機功耗小於0.1W的開關電源採用的控制晶片IC1，例如通嘉的LD7750，為了控制晶片本身更加節能，其將回饋端FB(LD7750命名為COMP)輸出的最大電流Ic調為0.32mA，使得光耦合器IC2的發光二極體的電流If僅為If=Ic/CTR=0.32mA/0.7=0.45mA(假設CTR=70%)。而目前TL431本身要求在正常工作時陰極端K最小的電流至少為1mA，故而與光耦合器IC2的發光二極體並聯的電阻器R14至少需要提供Ir14=1mA-0.45mA=0.55mA以上的電流，即電阻器R14的電阻值最大不能超過R14=Vf/Ir14=1V/0.55mA=1.8kΩ，故目前光耦合器IC2的發光二極體需並聯一電阻值約為1kΩ~1.8kΩ左右的電阻器R14，但是並聯該電阻器R14會使得回饋電路的回饋速度變慢，因而會產生輸出電壓Vout1在開機瞬間的過衝電壓問題。當回饋電路中其它元件參數設置不合理時，輸出電壓Vout1在開機瞬間的過衝電壓現象將更加嚴重，甚至會使主機板電路的部分元件毀壞，影響產品可靠性。 For the control chip IC1 of the switching power supply with standby power consumption less than 0.1W, for example, the LD7750 of Tongjia, in order to control the chip itself is more energy-saving, it adjusts the maximum current Ic outputted by the feedback terminal FB (LD7750 named COMP) to 0.32mA. The current If of the light-emitting diode of the photocoupler IC2 is made to be Only = Ic / CTR = 0.32 mA / 0.7 = 0.45 mA (assuming CTR = 70%). At present, the TL431 itself requires that the minimum current of the cathode terminal K is at least 1 mA during normal operation. Therefore, the resistor R14 connected in parallel with the light-emitting diode of the photocoupler IC2 needs to provide at least a current of Ir14=1mA-0.45mA=0.55mA or more. That is, the resistance value of the resistor R14 should not exceed R14=Vf/Ir14=1V/0.55mA=1.8kΩ, so the current LED of the optocoupler IC2 needs to be connected in parallel with a resistance value of about 1kΩ~1.8kΩ. R14, but paralleling the resistor R14 will slow down the feedback speed of the feedback circuit, thus causing an overshoot voltage problem at the instant of the output voltage Vout1. When the parameter setting of other components in the feedback circuit is unreasonable, the overshoot voltage phenomenon of the output voltage Vout1 at the moment of starting will be more serious, and even some components of the motherboard circuit may be destroyed, which may affect product reliability.
此外，該開關電源的控制晶片IC1在待機模式下為了更加節能，通常採用突發模式(burst-mode)控制方式。而控制晶片IC1的回饋端FB的波形通常會影響到突發模式的工作頻率及其輸出端GATE在突發模式包絡中輸出的PWM信號的脈波數及PWM信號的工作週期大小。當突發模式的工作頻率介於1kHz~4kHz人耳最敏感的頻段時，變壓器Tr1便產生異音。此時通常需要加大回饋端FB對接地端GND的電容器C11的電容值及光耦合器IC2的發光二極體輸入串聯的電阻器R6的電阻值，方可使突發模式的工作頻率落在小於1kHz的頻段，但是加大電容器C11的電容值及電阻器R6的電阻值也同樣 使回饋速度變慢，因而會產生輸出電壓Vout1在開機瞬間的過衝電壓問題。 In addition, the control chip IC1 of the switching power supply generally adopts a burst-mode control method in order to be more energy-saving in the standby mode. The waveform of the feedback terminal FB of the control chip IC1 usually affects the operating frequency of the burst mode and the pulse wave number of the PWM signal outputted by the output terminal GATE in the burst mode envelope and the duty cycle of the PWM signal. When the operating mode of the burst mode is between 1 kHz and 4 kHz, the most sensitive frequency of the human ear, the transformer Tr1 produces an abnormal sound. In this case, it is usually necessary to increase the capacitance value of the capacitor C11 of the feedback terminal FB to the ground GND and the resistance value of the resistor R6 of the photocoupler IC2 in series with the input of the LED, so that the operating frequency of the burst mode falls. The frequency band is less than 1 kHz, but the capacitance value of the capacitor C11 and the resistance value of the resistor R6 are also the same. The feedback speed is slowed down, thus causing an overshoot voltage problem at the instant of the output voltage Vout1.
本創作的目的在提出一種抑制開關電源在開機時輸出過衝電壓的電路，以改善開關電源的輸出電壓在開機瞬間的過衝電壓問題及在待機模式下採用突發模式控制時的變壓器異音問題。 The purpose of this creation is to propose a circuit for suppressing the output of the overshoot voltage when the switching power supply is turned on, so as to improve the overshoot voltage problem of the output voltage of the switching power supply at the startup instant and the transformer abnormal sound when using the burst mode control in the standby mode. problem.
為達到上述目的，本創作提出一種抑制開關電源在開機時輸出過衝電壓的電路，其中，開關電源包括開關電路及回饋電路，回饋電路包括回饋取樣電路及控制電路，開關電路具有第一電源輸出端及第二電源輸出端，第一電源輸出端輸出第一輸出電壓，第二電源輸出端輸出第二輸出電壓，回饋取樣電路電連接於第一電源輸出端及控制電路之間，控制電路電連接於回饋取樣電路及開關電路之間。該抑制開關電源在開機時輸出過衝電壓的電路包括一個電容器及一個電阻器，電容器的一端電連接於第二電源輸出端且另一端電連接於電阻器的一端，電阻器的另一端電連接於回饋取樣電路的取樣端。 In order to achieve the above object, the present invention proposes a circuit for suppressing the output of an overshoot voltage when the switching power supply is turned on. The switching power supply includes a switching circuit and a feedback circuit. The feedback circuit includes a feedback sampling circuit and a control circuit, and the switching circuit has a first power output. And the second power output end, the first power output terminal outputs a first output voltage, the second power output terminal outputs a second output voltage, and the feedback sampling circuit is electrically connected between the first power output end and the control circuit, and the control circuit is electrically Connected between the feedback sampling circuit and the switching circuit. The circuit for suppressing the output of the overshoot voltage when the switching power supply is turned on includes a capacitor and a resistor. One end of the capacitor is electrically connected to the output end of the second power source and the other end is electrically connected to one end of the resistor, and the other end of the resistor is electrically connected. The sampling end of the sampling circuit is fed back.
在本創作一實施例中，開關電源為反馳式開關電源，而開關電路為反馳式開關電路。 In an embodiment of the present invention, the switching power supply is a flyback switching power supply, and the switching circuit is a flyback switching circuit.
在本創作一實施例中，回饋取樣電路包括第一與第二取樣電阻器、三端並聯穩壓器、光耦合器及並聯電阻器，其中，第一取樣電阻器的一端電連接於第一電源輸出端且另一端電連接於回饋取樣電路的取樣端，第二取樣電阻器的一端電連接於回饋取樣電路的取樣端且另一端電連接於地，三端並聯穩壓器的參考端、陰極端及陽極端分別電連接於回饋取樣電路的取樣端、光耦合器輸入端的光發射器及地，光耦合器輸入端的光發射器還與並聯電阻器並聯電連接，光耦合器輸出端的光偵測器電連接於控制電路內部控制晶片的回饋端。 In an embodiment of the present invention, the feedback sampling circuit includes first and second sampling resistors, a three-terminal shunt regulator, an optical coupler, and a parallel resistor, wherein one end of the first sampling resistor is electrically connected to the first The output end of the power supply is electrically connected to the sampling end of the feedback sampling circuit, and one end of the second sampling resistor is electrically connected to the sampling end of the feedback sampling circuit and the other end is electrically connected to the ground, and the reference end of the three-terminal shunt regulator, The cathode end and the anode end are respectively electrically connected to the sampling end of the feedback sampling circuit, the light emitter of the optocoupler input end and the ground, and the light emitter of the optocoupler input end is also electrically connected in parallel with the parallel resistor, and the light of the output end of the optocoupler The detector is electrically connected to the feedback end of the control circuit internal control chip.
本創作因採用在輸出第二輸出電壓的第二電源輸出端及回饋取樣電路的取樣端之間串聯電連接一個電容器及一個電阻器，可改善與回饋取樣電路電連接的第一電源輸出端所輸出的第一輸出電壓在開機瞬間的過衝電壓問題，並可改善在待機模式下採用突發模式控制時的變壓器異音問題，從而提升了產品可靠性。 The present invention improves the first power output terminal electrically connected to the feedback sampling circuit by electrically connecting a capacitor and a resistor in series between the second power output terminal outputting the second output voltage and the sampling end of the feedback sampling circuit. The output of the first output voltage has an overshoot voltage problem at the instant of power-on, and can improve the transformer abnormal sound problem when using the burst mode control in the standby mode, thereby improving product reliability.
為讓本創作之上述和其他目的、特徵和優點能更明顯易懂，下文特舉較佳實施例，並配合所附圖式，作詳細說明如下。 The above and other objects, features and advantages of the present invention will become more apparent and understood.
C1~C11‧‧‧電容器 C1~C11‧‧‧ capacitor
D1、D2‧‧‧二極體 D1, D2‧‧‧ diode
IC1‧‧‧控制晶片 IC1‧‧‧Control Wafer
CS‧‧‧電流偵測端 CS‧‧‧current detection terminal
FB‧‧‧回饋端 FB‧‧‧ feedback end
GATE‧‧‧輸出端 GATE‧‧‧ output
GND‧‧‧接地端 GND‧‧‧ ground terminal
VCC‧‧‧供電端 VCC‧‧‧ power supply
IC2‧‧‧光耦合器 IC2‧‧‧Optocoupler
IC3‧‧‧三端並聯穩壓器 IC3‧‧‧Three-terminal shunt regulator
A‧‧‧陽極端 A‧‧‧Anode end
K‧‧‧陰極端 K‧‧‧ cathode end
R‧‧‧參考端 R‧‧‧ reference end
L1、L2‧‧‧電感器 L1, L2‧‧‧ inductors
Q1、Q2‧‧‧電晶體 Q1, Q2‧‧‧O crystal
R1~R7‧‧‧電阻器 R1~R7‧‧‧Resistors
R8‧‧‧第二取樣電阻器 R8‧‧‧Second sampling resistor
R9‧‧‧第一取樣電阻器 R9‧‧‧First Sampling Resistor
R10~R13‧‧‧電阻器 R10~R13‧‧‧Resistors
R14‧‧‧並聯電阻器 R14‧‧‧ parallel resistor
Tr1‧‧‧變壓器 Tr1‧‧‧Transformer
ZD1‧‧‧齊納二極體 ZD1‧‧‧Zina diode
P1‧‧‧第一電源輸出端 P1‧‧‧first power output
P2‧‧‧第二電源輸出端 P2‧‧‧second power output
P3‧‧‧取樣端 P3‧‧‧Sampling end
Vclk‧‧‧時脈信號 Vclk‧‧‧ clock signal
Vgate‧‧‧PWM信號 Vgate‧‧‧PWM signal
Vout1‧‧‧第一輸出電壓 Vout1‧‧‧ first output voltage
Vout2‧‧‧第二輸出電壓 Vout2‧‧‧second output voltage
V1、Vcs、Vcs1、Vcs2、Vfb、Vfb1、Vslope‧‧‧電壓 V1, Vcs, Vcs1, Vcs2, Vfb, Vfb1, Vslope‧‧‧ voltage
Ic、If、Ika‧‧‧電流 Ic, If, Ika‧‧‧ Current
T1~T4‧‧‧期間 During the period of T1~T4‧‧
圖1為現有液晶顯示產品AC-DC開關電源的一實施例電路圖。 1 is a circuit diagram of an embodiment of a conventional liquid crystal display product AC-DC switching power supply.
圖2為現有液晶顯示產品AC-DC開關電源的另一實施例電路圖。 2 is a circuit diagram of another embodiment of a conventional liquid crystal display product AC-DC switching power supply.
圖3為本創作液晶顯示產品AC-DC開關電源的一實施例電路圖。 FIG. 3 is a circuit diagram of an embodiment of an AC-DC switching power supply for a liquid crystal display product.
圖4為圖3所示開關電源的兩輸出電壓在開機時的波形圖。 FIG. 4 is a waveform diagram of two output voltages of the switching power supply shown in FIG. 3 at power-on.
圖5為圖3所示開關電源的輸出電壓及其回饋電路的電壓電流在開機時的波形圖。 FIG. 5 is a waveform diagram of the output voltage of the switching power supply shown in FIG. 3 and the voltage and current of the feedback circuit thereof at startup.
圖6為圖3所示開關電源的控制晶片內部的局部電路圖。 Figure 6 is a partial circuit diagram of the interior of the control wafer of the switching power supply of Figure 3.
圖7為現有開關電源在開機時兩輸出電壓實際量測所得到的波形圖。 Fig. 7 is a waveform diagram of actual measurement of two output voltages of a conventional switching power supply at power-on.
圖8為本創作的開關電源在開機時兩輸出電壓實際量測所得到的波形圖。 FIG. 8 is a waveform diagram of the actual measurement of the two output voltages when the switching power supply of the present invention is turned on.
請參見圖3，圖3為本創作液晶顯示產品AC-DC開關電源的一實施例電路圖。與圖2所示開關電源相比，圖3所示開關電源還包括一個電容器C10及一個電阻器R10，電容器C10的一端電連接於輸出第二輸出電壓Vout2的第二電源輸出端P2，電容器C10的另一端電連接於電阻器R10的一端，電阻器R10的另一端電連接於回饋電路(或回饋取樣電路)的取樣端P3。 Please refer to FIG. 3. FIG. 3 is a circuit diagram of an embodiment of an AC-DC switching power supply for a liquid crystal display product. Compared with the switching power supply shown in FIG. 2, the switching power supply shown in FIG. 3 further includes a capacitor C10 and a resistor R10. One end of the capacitor C10 is electrically connected to the second power output terminal P2 that outputs the second output voltage Vout2, and the capacitor C10 The other end of the resistor R10 is electrically connected to the sampling terminal P3 of the feedback circuit (or the feedback sampling circuit).
更具體的說，圖3所示開關電源為反馳式開關電源，其包括電磁干擾 (EMI)濾波電路、橋式整流電路、濾波電容器C1、反馳式開關電路及回饋電路，而回饋電路包括回饋取樣電路及控制電路。其中，市用交流電例如90Vrms~264Vrms輸入EMI濾波電路後，經過橋式整流電路的整流及濾波電容器C1的濾波後產生直流電提供給反馳式開關電路。反馳式開關電路包括變壓器Tr1、NMOS電晶體Q1、二極體D1和D2、電容器C4~C9、電阻器R2、R4和R5、電感器L1和L2及RCD吸收電路，反馳式開關電路具有第一電源輸出端P1及第二電源輸出端P2，第一電源輸出端P1輸出第一輸出電壓Vout1，第二電源輸出端P2輸出第二輸出電壓Vout2。在本實施例中，第一輸出電壓Vout1輸出一5V的直流電作為液晶顯示產品的主機板電路的供電電壓而需要較為精準，而第二輸出電壓Vout2輸出一16V的直流電作為液晶顯示產品的LED燈管驅動電路的輸入供電電壓。 More specifically, the switching power supply shown in Figure 3 is a flyback switching power supply that includes electromagnetic interference. (EMI) filter circuit, bridge rectifier circuit, filter capacitor C1, flyback switch circuit and feedback circuit, and feedback circuit includes feedback sampling circuit and control circuit. Among them, the city AC power, for example, 90Vrms~264Vrms input EMI filter circuit, after the rectifier of the bridge rectifier circuit and the filter capacitor C1 filter, DC power is supplied to the flyback switch circuit. The flyback switching circuit includes a transformer Tr1, an NMOS transistor Q1, diodes D1 and D2, capacitors C4 to C9, resistors R2, R4 and R5, inductors L1 and L2, and an RCD absorbing circuit, and the flyback switching circuit has The first power output terminal P1 and the second power output terminal P2, the first power output terminal P1 outputs a first output voltage Vout1, and the second power output terminal P2 outputs a second output voltage Vout2. In this embodiment, the first output voltage Vout1 outputs a direct current of 5V as the power supply voltage of the motherboard circuit of the liquid crystal display product, and the second output voltage Vout2 outputs a direct current of 16V as the LED light of the liquid crystal display product. The input supply voltage of the tube drive circuit.
回饋取樣電路電連接於第一電源輸出端P1及控制電路之間，回饋取樣電路包括第一取樣電阻器R9、第二取樣電阻器R8、三端並聯穩壓器IC3、光耦合器IC2、並聯電阻器R14、電阻器R6和R7及電容器C3。其中，第一取樣電阻器R9的一端電連接於第一電源輸出端P1且另一端電連接於回饋取樣電路的取樣端P3，第二取樣電阻器R8的一端電連接於回饋取樣電路的取樣端P3且另一端電連接於地，三端並聯穩壓器IC3的參考端R、陰極端K及陽極端A分別電連接於回饋取樣電路的取樣端P3、光耦合器IC2輸入端的光發射器及地，光耦合器IC2輸入端的光發射器還與並聯電阻器R14並聯電連接，光耦合器IC2輸出端的光偵測器電連接於控制電路。在本實施例中，三端並聯穩壓器IC3採用TL431，光耦合器IC2的光發射器及光偵測器分別採用發光二極體及光電晶體。 The feedback sampling circuit is electrically connected between the first power output terminal P1 and the control circuit, and the feedback sampling circuit comprises a first sampling resistor R9, a second sampling resistor R8, a three-terminal shunt regulator IC3, an optocoupler IC2, and a parallel connection. Resistor R14, resistors R6 and R7, and capacitor C3. Wherein, one end of the first sampling resistor R9 is electrically connected to the first power output terminal P1 and the other end is electrically connected to the sampling end P3 of the feedback sampling circuit, and one end of the second sampling resistor R8 is electrically connected to the sampling end of the feedback sampling circuit. P3 and the other end is electrically connected to the ground, and the reference terminal R, the cathode terminal K and the anode terminal A of the three-terminal shunt regulator IC3 are electrically connected to the sampling end P3 of the feedback sampling circuit and the light emitter of the input end of the optocoupler IC2, respectively. The light emitter of the input end of the optocoupler IC2 is also electrically connected in parallel with the parallel resistor R14, and the photodetector at the output of the optocoupler IC2 is electrically connected to the control circuit. In this embodiment, the three-terminal shunt regulator IC3 adopts the TL431, and the light emitter and the photodetector of the photocoupler IC2 respectively use a light-emitting diode and a photoelectric crystal.
控制電路電連接於回饋取樣電路及反馳式開關電路之間，控制電路包括控制晶片IC1、電阻器R1和R3、電容器C2和C11及供電電路。其中，控制 晶片IC1具有供電端VCC、接地端GND、電流偵測端CS、回饋端FB及輸出端GATE，供電端VCC接收供電電路的供電，電流偵測端CS偵測流過NMOS電晶體Q1(或變壓器Tr1初級側)的電流，回饋端FB接收回饋取樣電路針對輸出電壓Vout1取樣所得到的回饋電壓，輸出端GATE輸出PWM信號以通過NMOS電晶體Q1控制變壓器Tr1的能量傳輸，從而控制了輸出電壓Vout1以達到基本恆定的直流電壓。 The control circuit is electrically connected between the feedback sampling circuit and the flyback switching circuit. The control circuit includes a control chip IC1, resistors R1 and R3, capacitors C2 and C11, and a power supply circuit. Among them, control The chip IC1 has a power supply terminal VCC, a ground terminal GND, a current detection terminal CS, a feedback terminal FB and an output terminal GATE. The power supply terminal VCC receives the power supply of the power supply circuit, and the current detection terminal CS detects the flow through the NMOS transistor Q1 (or the transformer). The current of the Tr1 primary side, the feedback end FB receives the feedback voltage obtained by sampling the output voltage Vout1 by the feedback sampling circuit, and the output terminal GATE outputs a PWM signal to control the energy transmission of the transformer Tr1 through the NMOS transistor Q1, thereby controlling the output voltage Vout1. To achieve a substantially constant DC voltage.
下面對圖3所示開關電源做具體的原理及動作說明。請同時參見圖4及圖5，圖4為圖3所示開關電源的兩輸出電壓Vout1和Vout2在開機時的波形圖，而圖5為圖3所示開關電源的輸出電壓Vout1及其回饋電路的電壓電流在開機時的波形圖。在液晶顯示產品開機，即該開關電源輸入市用交流電時，於T1期間，兩輸出電壓Vout1和Vout2均從0V開始上升，而供電電路提供給控制晶片IC1的供電端VCC電壓也從0V開始上升。當控制晶片IC1的供電端VCC電壓達到啟動所需的電壓時，控制晶片IC1開始工作，控制晶片IC1的輸出端GATE將輸出一工作週期由小變大的PWM信號Vgate，此過程被稱為軟啟動。 The following is a detailed description of the principle and operation of the switching power supply shown in Figure 3. Please refer to FIG. 4 and FIG. 5 at the same time. FIG. 4 is a waveform diagram of two output voltages Vout1 and Vout2 of the switching power supply shown in FIG. 3 at startup, and FIG. 5 is an output voltage Vout1 of the switching power supply shown in FIG. The waveform of the voltage and current at startup. When the liquid crystal display product is turned on, that is, when the switching power supply is input to the commercial alternating current, during the period T1, the two output voltages Vout1 and Vout2 both rise from 0V, and the VCC voltage supplied from the power supply circuit to the power supply terminal of the control chip IC1 also rises from 0V. . When the VCC voltage of the power supply terminal of the control chip IC1 reaches the voltage required for startup, the control chip IC1 starts to work, and the output terminal GATE of the control chip IC1 outputs a PWM signal Vgate whose duty cycle is changed from small to large. This process is called soft. start up.
於T2期間，當PWM信號Vgate的工作週期大到一定值後將不再增大。從圖4可以看出，於T1和T2期間，兩輸出電壓Vout1和Vout2均從0V開始上升，基本上呈一定斜率線性上升，且第二輸出電壓Vout2上升的斜率較第一輸出電壓Vout1大得多。在輸出電壓Vout2上升時，電容器C10將在電阻器R8上產生一電流△I=C10×dv/dt，其中，C10為電容器C10的電容值，dv/dt為電容器C10兩端的電壓對時間變化率；同時輸出電壓Vout1在上升時也在電阻器R8上產生一電流I=Vout1/(R8+R9)，其中，R8和R9為電阻器R8和R9的電阻值；故在電阻器R8會產生一電壓V1=(I+△I)×R8=[Vout1/(R8+R9)+C10×dv/dt]×R8。因此，利用開機時輸出電壓Vout2 從0V開始呈一較大的線性斜率上升的變化電壓，使電容器C10產生一電流△I，該電流△I流過限流電阻器R10及三端並聯穩壓器IC3(如TL431)的參考端R對地的電阻器R8時，對TL431的參考端R產生一補充電壓，使得TL431的參考端R在輸出電壓Vout1還未達到正常輸出電壓5V之前即提前得到一稍大於或等於2.5V的電壓，使得TL431內部電晶體導通。 During T2, when the duty cycle of the PWM signal Vgate is large enough, it will not increase. As can be seen from FIG. 4, during T1 and T2, both output voltages Vout1 and Vout2 rise from 0V, and rise substantially linearly with a certain slope, and the slope of the second output voltage Vout2 rises larger than the first output voltage Vout1. many. When the output voltage Vout2 rises, the capacitor C10 will generate a current ΔI=C10×dv/dt on the resistor R8, where C10 is the capacitance value of the capacitor C10, and dv/dt is the voltage versus time rate of the capacitor C10. At the same time, the output voltage Vout1 also generates a current I=Vout1/(R8+R9) on the resistor R8, wherein R8 and R9 are the resistance values of the resistors R8 and R9; therefore, a resistor R8 is generated. Voltage V1 = (I + ΔI) × R8 = [Vout1/(R8 + R9) + C10 × dv / dt] × R8. Therefore, using the output voltage Vout2 at power-on Starting from 0V, a large linear slope rises the voltage, causing capacitor C10 to generate a current ΔI that flows through the reference terminal of current limiting resistor R10 and three-terminal shunt regulator IC3 (such as TL431). When the R to ground resistor R8, a complementary voltage is generated to the reference terminal R of the TL431, so that the reference terminal R of the TL431 obtains a voltage slightly greater than or equal to 2.5V before the output voltage Vout1 has reached the normal output voltage of 5V. So that the internal transistor of the TL431 is turned on.
例如，於T3期間一開始時，輸出電壓Vout1達到4.6V但還未達到正常輸出電壓5V)，此時電壓V1就已經提前達到TL431內部2.5V的參考電壓，故TL431內部電晶體的基極電壓開始增加，使得基極電流也開始增大，TL431內部電晶體的集極與射極之間開始產生一從0A開始增大的電流Ika。由於光耦合器IC2輸入端的發光二極體的正向電流If=Ika-Vf/R14，故光耦合器IC2輸入端的發光二極體將產生一從0A開始增大的電流If。又由於光耦合器IC2輸出端的光電晶體輸出的電流Ic=If×CTR，故光耦合器IC2輸出端的光電晶體將產生一從0A開始增大的電流Ic。該逐漸增大的電流Ic會使控制晶片IC1的回饋端FB的電壓Vfb被迅速拉低(後面會有說明原因)，使得控制晶片IC1從輸出端GATE輸出的PWM信號Vgate的工作週期減小，即變壓器T1次級側輸出的能量減小，使得輸出電壓Vout1在電壓在還未達到正常輸出電壓5V之前的那一小段電壓上升的斜率變得較為緩慢，即改善了輸出電壓Vout1在開機瞬間的過衝電壓問題。 For example, at the beginning of T3, the output voltage Vout1 reaches 4.6V but has not reached the normal output voltage of 5V. At this time, the voltage V1 has reached the reference voltage of 2.5V inside the TL431 in advance, so the base voltage of the internal transistor of the TL431. The increase begins, so that the base current also begins to increase, and a current Ika increasing from 0A begins to occur between the collector and the emitter of the internal transistor of the TL431. Since the forward current If=Ika-Vf/R14 of the light-emitting diode at the input end of the photocoupler IC2, the light-emitting diode at the input end of the photocoupler IC2 will generate a current If increased from 0A. Moreover, since the current Ic=If×CTR of the photo-crystal output at the output of the photocoupler IC2, the photo-crystal of the output of the photocoupler IC2 will generate a current Ic which increases from 0A. The gradually increasing current Ic causes the voltage Vfb of the feedback terminal FB of the control chip IC1 to be rapidly pulled down (the reason will be explained later), so that the duty cycle of the PWM signal Vgate outputted from the output terminal GATE by the control chip IC1 is reduced. That is, the energy output of the secondary side of the transformer T1 is reduced, so that the slope of the output voltage Vout1 rising at a small voltage before the voltage has reached the normal output voltage of 5V becomes slower, that is, the output voltage Vout1 is improved at the start-up instant. Overshoot voltage problem.
請再參見圖6，圖6為圖3所示開關電源的控制晶片IC1內部的局部電路圖。控制晶片IC1例如LD7750，其包括前緣遮蔽(LEB)模組、PWM比較器、過電流保護(OCP)比較器、或(OR)閘、PWM產生模組及其它如電阻、二極體等元件。控制晶片IC1內部的電壓Vfb1是由回饋端FB的電壓Vfb轉換而得到，電壓Vcs2是電流偵測端CS所偵測到的電壓Vcs經內部處理(先經LEB模組轉換成電壓Vcs1後再加上電壓Vslpoe做斜率補償)後轉換而得到。當光耦 合器IC2輸出端的光電晶體有電流Ic流過時，與光耦合器IC2電連接的控制晶片IC1的回饋端FB的電壓Vfb會被拉低，使得電壓Vfb1也被拉低，而且，當電流Ic越大時，電壓Vfb和Vfb1將被拉得越低。 Please refer to FIG. 6. FIG. 6 is a partial circuit diagram of the inside of the control chip IC1 of the switching power supply shown in FIG. The control chip IC1, such as the LD7750, includes a leading edge shield (LEB) module, a PWM comparator, an overcurrent protection (OCP) comparator, or an (OR) gate, a PWM generation module, and other components such as resistors, diodes, and the like. . The voltage Vfb1 inside the control chip IC1 is obtained by converting the voltage Vfb of the feedback terminal FB, and the voltage Vcs2 is the voltage Vcs detected by the current detecting terminal CS is internally processed (first converted into a voltage Vcs1 by the LEB module) The upper voltage Vslpoe is slope compensated) and then converted. Optocoupler When the photo-electric crystal at the output of the combiner IC2 has a current Ic flowing, the voltage Vfb of the feedback terminal FB of the control chip IC1 electrically connected to the photocoupler IC2 is pulled down, so that the voltage Vfb1 is also pulled low, and, when the current Ic is higher When large, the voltages Vfb and Vfb1 will be pulled lower.
當控制晶片IC1內部的時脈信號Vclk為高準位時，NMOS電晶體Q1導通，此時變壓器Tr1初級側產生一基本呈線性上升的電流流過電阻器R2，並經由電阻器R3及電容器C2的低通濾波後產生電壓Vcs而被控制晶片IC1的電流偵測端CS所偵測到，電壓Vcs最終轉換成電壓Vcs2與電壓Vfb1進行比較。當比較至Vcs2≧Vfb1時，控制晶片IC1從輸出端GATE輸出的PWM信號Vgate為低準位，使得NMOS電晶體Q1關閉，直到時脈信號Vclk的下一個高準位時，NMOS電晶體Q1才能再導通。因此，當電壓Vfb1越低時，NMOS電晶體Q1的導通時間越短、關閉時間越長，變壓器Tr1次級側輸出的能量就越小。也就是說，電壓Vfb將控制著控制晶片IC1從輸出端GATE輸出的PWM信號Vgate高低準位的時間長短，即控制著PWM信號Vgate的工作週期大小，也即控制著變壓器Tr1次級側輸出能量的大小。 When the clock signal Vclk inside the control chip IC1 is at a high level, the NMOS transistor Q1 is turned on. At this time, the primary side of the transformer Tr1 generates a substantially linear rising current flowing through the resistor R2, and via the resistor R3 and the capacitor C2. After the low-pass filtering, the voltage Vcs is generated and detected by the current detecting terminal CS of the control chip IC1, and the voltage Vcs is finally converted into a voltage Vcs2 and compared with the voltage Vfb1. When comparing to Vcs2≧Vfb1, the PWM signal Vgate outputted from the output terminal GATE of the control chip IC1 is at a low level, so that the NMOS transistor Q1 is turned off, until the next high level of the clock signal Vclk, the NMOS transistor Q1 can Turn it on again. Therefore, when the voltage Vfb1 is lower, the shorter the on-time of the NMOS transistor Q1 and the longer the off time, the smaller the energy output from the secondary side of the transformer Tr1. That is to say, the voltage Vfb will control the length of time of the PWM signal Vgate outputted by the control chip IC1 from the output terminal GATE, that is, control the duty cycle of the PWM signal Vgate, that is, control the output energy of the secondary side of the transformer Tr1. the size of.
請再參見圖5，於T3期間，隨著光耦合器IC2輸出的電流Ic的增加，控制晶片IC1從輸出端GATE輸出的PWM信號Vgate的工作週期將逐漸減小，使得輸出電壓Vout1和Vout2上升速度變得比較緩慢，上升的斜率變小，改善了輸出電壓Vout1在開機瞬間的過衝電壓問題，確保主機板電路所有元件在開關電源開機時不會因耐壓問題而被毀壞，從而提升了液晶顯示產品的可靠性。此外，還同時改善了在待機模式下採用突發模式控制時變壓器Tr1異音問題的解決難度，以往為改善該異音問題因需要考慮到輸出電壓Vout1的過衝電壓問題而使得電容器C11的電容值及電阻器R6的電阻值參數不能做較大幅度的修改，而本創作因改善了輸出電壓Vout1的過衝電壓問題而可以使電容器C11的電容值及電阻器R6的電阻值參數做較大幅度的修改來解決該異 音問題。 Referring again to FIG. 5, during the period T3, as the current Ic outputted by the optocoupler IC2 increases, the duty cycle of the PWM signal Vgate output from the output terminal GATE of the control chip IC1 will gradually decrease, so that the output voltages Vout1 and Vout2 rise. The speed becomes slower and the rising slope becomes smaller, which improves the overshoot voltage problem of the output voltage Vout1 at the moment of starting, ensuring that all components of the motherboard circuit are not destroyed by the withstand voltage problem when the switching power supply is turned on, thereby improving the speed. The reliability of liquid crystal display products. In addition, it also improves the difficulty of solving the abnormal sound problem of the transformer Tr1 when using the burst mode control in the standby mode. In the past, in order to improve the abnormal sound problem, the capacitance of the capacitor C11 is required due to the overshoot voltage problem of the output voltage Vout1. The value and the resistance value of the resistor R6 cannot be modified to a large extent, and the present invention can make the capacitance value of the capacitor C11 and the resistance value of the resistor R6 larger due to the improvement of the overshoot voltage problem of the output voltage Vout1. Modification of the amplitude to resolve the difference Sound problem.
於T4期間，當輸出電壓Vout1升到正常輸出電壓5V時，輸出電壓Vout1和Vout2均還未被吃載，控制晶片IC1的回饋端FB的電壓將保持著較低的準位，而控制晶片IC1的輸出端GATE將仍輸出較小工作週期的PWM信號Vgate。 During the period of T4, when the output voltage Vout1 rises to the normal output voltage of 5V, the output voltages Vout1 and Vout2 are not yet loaded, and the voltage of the feedback terminal FB of the control chip IC1 will remain at a lower level, and the control chip IC1 is controlled. The output GATE will still output a small duty cycle PWM signal Vgate.
請參見圖7，圖7為現有開關電源在開機時兩輸出電壓Vout1和Vout2實際量測所得到的波形圖，從圖中可以看出輸出電壓Vout1有產生過衝電壓現象。請再參見圖8，圖8為本創作的開關電源在開機時兩輸出電壓Vout1和Vout2實際量測所得到的波形圖，從圖中可以看出輸出電壓Vout1沒有產生過衝電壓現象。 Please refer to FIG. 7. FIG. 7 is a waveform diagram of the actual measurement of the two output voltages Vout1 and Vout2 when the switching power supply is turned on. It can be seen from the figure that the output voltage Vout1 has an overshoot voltage phenomenon. Please refer to FIG. 8 again. FIG. 8 is a waveform diagram of the actual measurement of the two output voltages Vout1 and Vout2 when the switching power supply is turned on. It can be seen from the figure that the output voltage Vout1 does not generate an overshoot voltage phenomenon.
雖然本創作已以較佳實施例揭露如上，然其並非用於限定本創作，任何熟習此技藝者，在不脫離本創作之精神和範圍內，當可作些許之更動與潤飾，因此本創作之保護範圍當視後附之申請專利範圍所界定者為準。 Although the present invention has been disclosed in the above preferred embodiments, it is not intended to limit the present invention, and anyone skilled in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of protection is subject to the definition of the scope of the patent application.
C1~C11‧‧‧電容器 C1~C11‧‧‧ capacitor
D1、D2‧‧‧二極體 D1, D2‧‧‧ diode
IC1‧‧‧控制晶片 IC1‧‧‧Control Wafer
CS‧‧‧電流偵測端 CS‧‧‧current detection terminal
FB‧‧‧回饋端 FB‧‧‧ feedback end
GATE‧‧‧輸出端 GATE‧‧‧ output
GND‧‧‧接地端 GND‧‧‧ ground terminal
VCC‧‧‧供電端 VCC‧‧‧ power supply
IC2‧‧‧光耦合器 IC2‧‧‧Optocoupler
IC3‧‧‧三端並聯穩壓器 IC3‧‧‧Three-terminal shunt regulator
A‧‧‧陽極端 A‧‧‧Anode end
K‧‧‧陰極端 K‧‧‧ cathode end
R‧‧‧參考端 R‧‧‧ reference end
L1、L2‧‧‧電感器 L1, L2‧‧‧ inductors
Q1、Q2‧‧‧電晶體 Q1, Q2‧‧‧O crystal
R1~R7‧‧‧電阻器 R1~R7‧‧‧Resistors
R8‧‧‧第二取樣電阻器 R8‧‧‧Second sampling resistor
R9‧‧‧第一取樣電阻器 R9‧‧‧First Sampling Resistor
R10~R13‧‧‧電阻器 R10~R13‧‧‧Resistors
R14‧‧‧並聯電阻器 R14‧‧‧ parallel resistor
Tr1‧‧‧變壓器 Tr1‧‧‧Transformer
ZD1‧‧‧齊納二極體 ZD1‧‧‧Zina diode
P1‧‧‧第一電源輸出端 P1‧‧‧first power output
P2‧‧‧第二電源輸出端 P2‧‧‧second power output
P3‧‧‧取樣端 P3‧‧‧Sampling end
Vgate‧‧‧PWM信號 Vgate‧‧‧PWM signal
Vout1‧‧‧第一輸出電壓 Vout1‧‧‧ first output voltage
Vout2‧‧‧第二輸出電壓 Vout2‧‧‧second output voltage
V1、Vcs、Vfb‧‧‧電壓 V1, Vcs, Vfb‧‧‧ voltage
Ic、If、Ika‧‧‧電流 Ic, If, Ika‧‧‧ Current
Claims (3)
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2012204010672U CN202818086U (en) | 2012-08-14 | 2012-08-14 | Circuit inhibiting switching power supply from outputting overshoot voltage during power-on |
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| Publication Number | Publication Date |
|---|---|
| TWM457343U true TWM457343U (en) | 2013-07-11 |
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| TW101222454U TWM457343U (en) | 2012-08-14 | 2012-11-20 | Circuit for inhibiting switching power supply outputting overshoot voltage at startup |
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| CN (1) | CN202818086U (en) |
| TW (1) | TWM457343U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI551022B (en) * | 2014-11-11 | 2016-09-21 | Dynamic drive capability adjustment of the power control device | |
| TWI650628B (en) * | 2017-08-31 | 2019-02-11 | 大陸商北京集創北方科技股份有限公司 | Voltage regulator |
| TWI761902B (en) * | 2020-08-10 | 2022-04-21 | 大陸商艾科微電子（深圳）有限公司 | Power controller capable of providing short circuit protection and control method thereof |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104682707A (en) * | 2013-11-28 | 2015-06-03 | 深圳市海洋王照明工程有限公司 | Switching power supply for selectable output of voltage |
| CN104901563A (en) * | 2015-06-19 | 2015-09-09 | 温州市麦特力克电器有限公司 | USB socket |
| TWI548185B (en) * | 2015-10-30 | 2016-09-01 | 通嘉科技股份有限公司 | Power control method and related apparatus capable of providing compensation to inductance variation |
| CN109617385B (en) * | 2019-02-12 | 2023-12-15 | 武汉永力睿源科技有限公司 | Capacitor precharge circuit |
-
2012
- 2012-08-14 CN CN2012204010672U patent/CN202818086U/en not_active Expired - Fee Related
- 2012-11-20 TW TW101222454U patent/TWM457343U/en not_active IP Right Cessation
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI551022B (en) * | 2014-11-11 | 2016-09-21 | Dynamic drive capability adjustment of the power control device | |
| TWI650628B (en) * | 2017-08-31 | 2019-02-11 | 大陸商北京集創北方科技股份有限公司 | Voltage regulator |
| TWI761902B (en) * | 2020-08-10 | 2022-04-21 | 大陸商艾科微電子（深圳）有限公司 | Power controller capable of providing short circuit protection and control method thereof |
| US11632036B2 (en) | 2020-08-10 | 2023-04-18 | Ark Semiconductor Corp. Ltd. | Power controller with short-circuited protection and method of controlling the same |
Also Published As
| Publication number | Publication date |
|---|---|
| CN202818086U (en) | 2013-03-20 |
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