TWI740663B

TWI740663B - Power supply capable of stabilizing compensation current

Info

Publication number: TWI740663B
Application number: TW109133085A
Authority: TW
Inventors: 詹子增
Original assignee: 宏碁股份有限公司
Priority date: 2020-09-24
Filing date: 2020-09-24
Publication date: 2021-09-21
Also published as: TW202213917A

Abstract

A power supply includes a transformer, a feedback circuit, a voltage-stabilizing compensation circuit, a PWM integrated circuit, and a power switch. The transformer is configured to convert an input voltage received on a primary side into an output voltage on a secondary side. The feedback circuit is configured to provide compensation current according to the output voltage and convert the compensation current into a feedback voltage. The voltage-stabilizing compensation circuit includes a BJT which operates in an active region for stabilizing the compensation current. The PWM integrated circuit is configured to selectively turn on or off the power switch, thereby modulating the conversion ratio of the transformer.

Description

具穩定補償電流設計之電源供應器 Power supply with stable compensation current design

本發明相關於一種具穩定補償電流設計之電源供應器，尤指一種使用運作於主動區之雙極接面電晶體來穩定補償電流之電源供應器。 The present invention relates to a power supply with a stable compensation current design, in particular to a power supply that uses a bipolar junction transistor operating in the active area to stabilize the compensation current.

電腦系統中不同組件所需的操作電壓不同，因此普遍採用電源供應器(power supply)以通過變壓、整流與濾波的方式，將交流電(AC)室內電源轉換為直流電(DC)以驅動不同零組件。傳統馳返式架構下的電源供應器會使用一功率開關來控制變壓器的初級側路徑，並使用一整流開關來控制變壓器的次級側路徑。當功率開關導通時，輸入電能會轉換而磁能而儲存在變壓器中，此時會截止整流開關以隔絕輸出路徑；當功率開關截止時，變壓器內存能量會經由導通之整流開關釋放至輸出端，並藉由一輸出電容來平滑電量輸出。 Different components in a computer system require different operating voltages. Therefore, power supplies are commonly used to convert alternating current (AC) indoor power into direct current (DC) by means of voltage transformation, rectification, and filtering to drive different components. Components. The power supply under the traditional flyback architecture uses a power switch to control the primary side path of the transformer, and a rectifier switch to control the secondary side path of the transformer. When the power switch is turned on, the input electrical energy will be converted and the magnetic energy will be stored in the transformer. At this time, the rectifier switch will be turned off to isolate the output path; when the power switch is turned off, the energy stored in the transformer will be released to the output terminal through the turned on rectifier switch, and An output capacitor is used to smooth the power output.

傳統電源供應器的外殼溫度因受到效率和熱損耗之影響，需加入較大的散熱片及散熱元件來達到溫度均勻，導致有著體積較大等問題，使功率密度較低。一個改善方法是在相同輸出功率的條件下將輸出電壓提高，透過降低其輸出電流以降低電源供應器整體之關鍵零組件溫度。然而，由於輸出電壓會有誤差範圍(通常為±5%)，提高輸出電壓之值會增加回授補償範圍。舉例來說，假設輸出電壓之誤差範圍為±5%)，當輸出電壓之值為19V時，其回授補償範圍為1.9V(19V*10%)；當輸出電壓之值為40V時，其回授補償範圍為4V(40V*10%)。 Due to the effect of efficiency and heat loss on the shell temperature of traditional power supplies, larger heat sinks and heat dissipation elements need to be added to achieve uniform temperature, which leads to problems such as larger volume and lower power density. One way to improve is to combine The output voltage is increased, and the temperature of the key components of the power supply is reduced by reducing its output current. However, since the output voltage has an error range (usually ±5%), increasing the value of the output voltage will increase the feedback compensation range. For example, assuming that the error range of the output voltage is ±5%), when the output voltage value is 19V, the feedback compensation range is 1.9V (19V*10%); when the output voltage value is 40V, its The feedback compensation range is 4V (40V*10%).

當輸出電壓上下限差距較大，為了使其電壓穩定，回授補償範圍必須增大，而回授補償範圍較大會導致其補償電流較不穩定，造成輸出端震盪，因此需要一種具穩定補償電流設計之電源供應器。 When the difference between the upper and lower limits of the output voltage is large, in order to make the voltage stable, the feedback compensation range must be increased, and a larger feedback compensation range will cause the compensation current to be unstable and cause the output end to oscillate. Therefore, a stable compensation current is required. Designed power supply.

本發明提供一種具穩定補償電流設計之電源供應器，其包含一輸入端、一輸出端、一變壓器、一回授電路、一穩壓補償電路、一脈衝寬度調變積體電路，以及一功率開關。該輸入端用來接收一輸入電壓，且該輸出端用來輸出該輸出電壓。該變壓器用來將該輸入電壓從一初級側感應至一次級側以供應該輸出電壓。該回授電路用來依據該輸出電壓來提供一補償電流，並將該補償電流轉換成一回授電壓。該穩壓補償電路包含一雙極接面電晶體，該雙極接面電晶體操作在一主動區以穩定該補償電流。該脈衝寬度調變積體電路用來依據該回授電壓來提供一控制訊號，並調整該控制訊號之工作週期。該功率開關用來依據該控制訊號而選擇性地導通或截止，以調節該變壓器從該初級側感應至該次級側之能量。 The present invention provides a power supply with a stable compensation current design, which includes an input terminal, an output terminal, a transformer, a feedback circuit, a stabilizing compensation circuit, a pulse width modulation integrated circuit, and a power supply switch. The input terminal is used to receive an input voltage, and the output terminal is used to output the output voltage. The transformer is used to induce the input voltage from a primary side to a secondary side to supply the output voltage. The feedback circuit is used to provide a compensation current according to the output voltage and convert the compensation current into a feedback voltage. The voltage stabilizing compensation circuit includes a bipolar junction transistor, and the bipolar junction transistor operates in an active area to stabilize the compensation current. The pulse width modulation integrated circuit is used to provide a control signal according to the feedback voltage and adjust the duty cycle of the control signal. The power switch is used for selectively turning on or off according to the control signal to adjust the energy induced by the transformer from the primary side to the secondary side.

10:脈衝寬度調變積體電路 10: Pulse width modulation integrated circuit

20:回授電路 20: Feedback circuit

22:發光二極體 22: Light-emitting diode

24:光敏電晶體 24: Photosensitive transistor

30:穩壓補償電路 30: Voltage regulator compensation circuit

100:電源供應器 100: power supply

NP1:初級側繞組和匝數 NP1: Primary side winding and number of turns

NS1:次級側繞組和匝數 NS1: Secondary winding and number of turns

GND1、GND2:接地電位 GND1, GND2: ground potential

TR:變壓器 TR: Transformer

Q1:功率開關 Q1: Power switch

C_OUT:輸出電容 C _OUT : output capacitance

D_OUT:輸出二極體 D _OUT : output diode

C_FB:回授電容 C _FB : feedback capacitor

C_C:補償電容 C _C : Compensation capacitor

C_X:抗雜訊電容 C _X : Anti-noise capacitance

R_D1、R_D2:分壓電阻 R _D1 , R _D2 : voltage divider resistance

BJT:雙極接面電晶體 BJT: Bipolar junction transistor

R1-R3:電阻 R1-R3: resistance

ZD:稽納二極體 ZD: Sensing diode

D_X:抗雜訊二極體 D _X : Anti-noise diode

PC:線性光耦合器 PC: Linear Optocoupler

TL:穩壓器 TL: voltage regulator

K:陰極端 K: cathode end

A:陽極端 A: Anode

R:參考端 R: Reference terminal

V_IN:輸入電壓 V _IN : Input voltage

V_OUT:輸出電壓 V _OUT : output voltage

V_FB:回授電壓 V _FB : Feedback voltage

V_REF:參考電壓 V _REF : Reference voltage

V_KA:穩壓器跨壓 V _KA : Voltage regulator cross voltage

I_IN:輸入電流 I _IN : Input current

I_OUT:輸出電壓 I _OUT : output voltage

GD1:控制訊號 GD1: Control signal

V_BE:基極-射極電壓 V _BE : base-emitter voltage

V_BC:基極-集極電壓 V _BC : base-collector voltage

V_CE:代表集極-射極電壓 V _CE : stands for collector-emitter voltage

I_C:補償電流 I _C : Compensation current

I_B:基極電流 I _B : base current

第1圖為本發明實施例中一種具穩定補償電流設計之電源供應器的功能方塊圖。 Figure 1 is a functional block diagram of a power supply with a stable compensation current design in an embodiment of the present invention.

第2圖為本發明實施例電源供應器實作方式之示意圖。 Figure 2 is a schematic diagram of the implementation of the power supply according to the embodiment of the present invention.

第3圖為本發明電源供應器中雙極接面電晶體運作時相關電壓和電流之示意圖。 Figure 3 is a schematic diagram of the relevant voltage and current when the bipolar junction transistor in the power supply of the present invention is operating.

第4圖為本發明穩壓補償電路在輸出電壓具下限值運作時相關電壓和電流之示意圖。 Figure 4 is a schematic diagram of the relevant voltage and current when the voltage stabilizing compensation circuit of the present invention is operating at a lower limit of the output voltage.

第5圖為本發明穩壓補償電路在輸出電壓具上限值運作時相關電壓和電流之示意圖。 Figure 5 is a schematic diagram of the relevant voltage and current when the voltage stabilizing compensation circuit of the present invention is operating at an upper limit of the output voltage.

第1圖為本發明實施例中一種具穩定補償電流設計之電源供應器100的功能方塊圖。電源供應器100包含一變壓器TR、一功率開關Q1、一輸出電容C_OUT、一輸出二極體D_OUT、一脈衝寬度調變積體電路10、一回授電路20，以及一穩壓補償電路30。電源供應器100可對其輸入端接收到之輸入電壓V_IN進行電壓轉換，以於一輸出端提供一輸出電壓V_OUT以驅動一負載。穩壓補償電路30耦接至輸出電壓V_OUT，其依據輸出電壓V_OUT之誤差範圍而設計，可依據輸出電壓V_OUT之變化提供一補償電流I_C。回授電路20耦接至輸出電壓V_OUT，可依據輸出電壓V_OUT之值提供一回授電壓V_FB。脈衝寬度調變積體電路10可依據回授電壓V_FB來提供控制訊號GD1，並調整控制訊號GD1之工作週期(duty cycle)，進而選擇性地導通或截止功率開關Q1以調節變壓器TR從初級側感應至次級側之能量。I_IN代表電源供應器100運作時之輸入電流，I_OUT代表電源供應器 100運作時之輸出電流。 FIG. 1 is a functional block diagram of a power supply 100 with a stable compensation current design according to an embodiment of the present invention. The power supply 100 includes a transformer TR, a power switch Q1, an output capacitor C _OUT , an output diode D _OUT , a pulse width modulation integrated circuit 10, a feedback circuit 20, and a voltage stabilizing compensation circuit 30. The power supply 100 can _{perform voltage conversion on the input voltage V IN} received at its input terminal to provide an output voltage V _OUT at an output terminal to drive a load. Regulator compensation circuit 30 coupled to the output voltage V _OUT, which is based on the error range of the output voltage V _OUT and designed to provide a compensation current I _C according to the change of the output voltage V _OUT. The feedback circuit 20 is coupled to the output voltage V _OUT , and can provide a feedback voltage V _FB _{according to the value of the output voltage V OUT} . The pulse width modulation integrated circuit 10 can _{provide the control signal GD1 according to the feedback voltage V FB} , and adjust the duty cycle of the control signal GD1, and then selectively turn on or turn off the power switch Q1 to adjust the transformer TR from the primary The side induces energy to the secondary side. I _IN represents the input current when the power supply 100 is in operation, and I _OUT represents the output current when the power supply 100 is in operation.

第2圖為本發明實施例電源供應器100實作方式之示意圖。變壓器TR包含一初級側繞組(由匝數NP1來表示)和一次級側繞組(由匝數NS1來表示)，每一繞組各包含一打點端和一非打點端，其中打點端以圓點標示。初級側繞組NP1之打點端耦接於輸入電壓V_IN，而其非打點端透過功率開關Q1耦接至一接地電位GND1。次級側繞組NS1之非打點端透過輸出二極體D_OUT耦接於輸出電壓V_OUT，而其打點端耦接至一接地電位GND2。在變壓器TR之運作中，相關電壓和電流之關係為V_IN/V_OUT=I_OUT/I_IN=NP1/NS1。在升壓應用中，次級側繞組之匝數NS1大於初級側繞組之匝數NP1；在降壓應用中，次級側繞組之匝數NS1小於初級側繞組之匝數NP1。在本發明一實施例中，NP1和NS1、之值的比例可為40：2，然而變壓器TR中初級側繞組之匝數NP1和次級側繞組之匝數NS1並不限定本發明之範疇。 FIG. 2 is a schematic diagram of the implementation of the power supply 100 according to the embodiment of the present invention. The transformer TR includes a primary side winding (represented by the number of turns NP1) and a secondary side winding (represented by the number of turns NS1). Each winding includes a dotted end and a non-dotted end. The dotted end is marked by a dot . The dotted end of the primary side winding NP1 is coupled to the input voltage V _IN , and the non-dotted end of the primary winding NP1 is coupled to a ground potential GND1 through the power switch Q1. NS1 Non-striking end windings of the secondary side through the output diode D _OUT coupled to the output voltage V _OUT, and its dot terminal coupled to a ground potential GND2. In the operation of the transformer TR, the relationship between the relevant voltage and current is V _IN /V _OUT =I _OUT /I _IN =NP1/NS1. In boost applications, the number of turns NS1 of the secondary side winding is greater than the number of turns NP1 of the primary side winding; in the step-down application, the number of turns NS1 of the secondary side winding is less than the number of turns NP1 of the primary side winding. In an embodiment of the present invention, the ratio of the values of NP1 and NS1 may be 40:2. However, the number of turns NP1 of the primary side winding and the number of turns NS1 of the secondary side winding in the transformer TR does not limit the scope of the present invention.

功率開關Q1之第一端耦接至初級側繞組NP1之非打點端，其第二端耦接至接地電位GND1，而控制端耦接至脈衝寬度調變積體電路10以接收控制訊號GD1。如前所述，回授電壓V_FB之值相關於輸出電壓V_OUT之值，而脈衝寬度調變積體電路10是依據回授電壓V_FB來提供控制訊號GD1並調整控制訊號GD1之工作週期，進而選擇性地導通或截止功率開關Q1以調節變壓器TR從初級側感應至次級側之能量，因此能達到穩定輸出電壓V_OUT的效果。 The first end of the power switch Q1 is coupled to the non-switching end of the primary winding NP1, the second end is coupled to the ground potential GND1, and the control end is coupled to the pulse width modulation integrated circuit 10 to receive the control signal GD1. As mentioned above, _{the value of the feedback voltage V FB} is related to the value of the output voltage V _OUT , and the pulse width modulation integrated circuit 10 provides the control signal GD1 and adjusts the duty cycle of the control signal GD1 _{according to the feedback voltage V FB} , And then selectively turn on or turn off the power switch Q1 to adjust the energy induced by the transformer TR from the primary side to the secondary side, so that the effect _{of stabilizing the output voltage V OUT can be achieved.}

回授電路20包含一回授電容C_FB、一補償電容C_C、分壓電阻 R_D1和R_D2、一線性光耦合器PC，以及一穩壓器TL。分壓電阻R_D1和R_D2串聯於輸出電壓V_OUT和接地電位GND2之間，可在分壓電阻R_D2上建立相關輸出電壓V_OUT之一參考電壓V_REF，其中V_REF=V_OUT＊R_D2/(R_D1+R_D2)。穩壓器TL包含一陰極端K、一陽極端A，以及一參考端R，可依據參考端R之狀態來調整流經陰極端K和陽極端A之補償電流I_C。穩壓器TL之參考端R耦接於分壓電阻R_D1和R_D2之間以接收參考電壓V_REF，穩壓器TL之陽極端A耦接至接地電位GND2，而陰極端K耦接至穩壓補償電路30，其中V_KA代表穩壓器TL陰極端K和陽極端A之間的跨壓。穩壓器TL會將其參考端R接收到之參考電壓V_REF和一內建基準電壓做誤差比較。當有誤差值發生時，耦接於穩壓器TL之陰極端K和參考端R之間的補償電容C_C可依此調整穩壓器TL之增益，使得補償電流I_C之值能反應輸出電壓V_OUT之值。 The feedback circuit 20 includes a feedback capacitor C _FB , a compensation capacitor C _C , voltage dividing resistors R _D1 and R _D2 , a linear optocoupler PC, and a voltage regulator TL. The voltage dividing resistors R _D1 and R _{D2 are} connected in series between the output voltage V _OUT and the ground potential GND2, and a reference voltage V _{REF of the} relevant output voltage V _OUT can be established on the voltage dividing resistor R _D2 , where V _REF =V _OUT *R _D2 /(R _D1 +R _D2 ). The voltage regulator TL includes a cathode terminal K, an anode terminal A, and a reference terminal R. The compensation current I _{C flowing through the cathode terminal K and the anode terminal A can be adjusted according to the state of the reference terminal R.} The reference terminal R of the voltage stabilizer TL is coupled between the voltage dividing resistors R _D1 and R _D2 to receive the reference voltage V _REF . The anode terminal A of the voltage stabilizer TL is coupled to the ground potential GND2, and the cathode terminal K is coupled to The voltage stabilization compensation circuit 30, where V _KA represents the cross voltage between the cathode terminal K and the anode terminal A of the voltage stabilizer TL. The voltage regulator TL compares the reference voltage V _REF received by its reference terminal R with a built-in reference voltage for error. _{When an error occurs, the compensation capacitor C C} coupled between the cathode terminal K and the reference terminal R of the voltage stabilizer TL can adjust the gain of the voltage stabilizer TL accordingly, so that the value of the _{compensation current I C can reflect the output} The value of the voltage V _OUT.

線性光耦合器PC包含一發光二極體22和一光敏電晶體24，可在變壓器TR之次級側和初級側之間進行電-光-電轉換。發光二極體22設置在變壓器TR之次級側，且耦接於線性光耦合器PC之第一輸入端和第二輸入端之間。光敏電晶體24設置在變壓器TR之初級側，且耦接於線性光耦合器PC之第一輸出端和第二輸出端之間。如前所述，由於流經發光二極體22之補償電流I_C相關輸出電壓V_OUT之值，線性光耦合器PC可利用輸入側之發光二極體22來感應輸出電壓V_OUT之變化量，並將相關輸出電壓V_OUT變化量之電能轉換成光能，再由輸出側之光敏電晶體接收後轉換成一回授電流I_FB，進而對回授電容C_FB充電以提供相對應之回授電壓V_FB。 The linear optical coupler PC includes a light emitting diode 22 and a photosensitive transistor 24, which can perform electrical-optical-electrical conversion between the secondary side and the primary side of the transformer TR. The light emitting diode 22 is arranged on the secondary side of the transformer TR and is coupled between the first input terminal and the second input terminal of the linear optocoupler PC. The photosensitive transistor 24 is arranged on the primary side of the transformer TR and is coupled between the first output terminal and the second output terminal of the linear optocoupler PC. As mentioned above, due to the value of the output voltage V _OUT _{related to the compensation current I C} flowing through the light-emitting diode 22, the linear optocoupler PC can use the light-emitting diode 22 on the input side to sense the change in the _{output voltage V OUT} , And convert the electrical energy related to the _{variation of the output voltage V OUT} into light energy, which is then received by the photosensitive transistor on the output side and converted into a feedback current I _FB , and then the feedback capacitor C _{FB is} charged to provide the corresponding feedback Voltage V _FB .

穩壓補償電路30包含一雙極接面電晶體(bipolar junction transistor)BJT、電阻R1-R3、稽納二極體ZD、一抗雜訊電容C_X，以及一抗雜訊二極體D_X。電阻R1耦接於雙極接面電晶體BJT之基極和輸出電壓V_OUT之間，電阻R2耦接於雙極接面電晶體BJT之集極和基極之間，而電阻R3耦接於雙極接面電晶體BJT之射極和穩壓器TL之陰極端K之間。雙極接面電晶體BJT之集極耦接至線性光耦合器PC中發光二極體22之陰極，其射極透過電阻R3耦接至穩壓器TL之陰極端K，而其基極透過電阻R1耦接至輸出電壓V_OUT。稽納二極體ZD陽極耦接至穩壓器TL之陰極端K，而其陰極耦接至雙極接面電晶體BJT之基極。 The voltage stabilizing compensation circuit 30 includes a bipolar junction transistor BJT, resistors R1-R3, a sensing diode ZD, a primary anti-noise capacitor C _X , and a primary anti-noise diode D _X . The resistor R1 is coupled between the base of the bipolar junction transistor BJT and the output voltage V _OUT , the resistor R2 is coupled between the collector and the base of the bipolar junction transistor BJT, and the resistor R3 is coupled between Between the emitter of the bipolar junction transistor BJT and the cathode terminal K of the voltage regulator TL. The collector of the bipolar junction transistor BJT is coupled to the cathode of the light-emitting diode 22 in the linear optocoupler PC, its emitter is coupled to the cathode terminal K of the voltage regulator TL through the resistor R3, and its base transmits through The resistor R1 is coupled to the output voltage V _OUT . The anode of the sensing diode ZD is coupled to the cathode terminal K of the voltage regulator TL, and its cathode is coupled to the base of the bipolar junction transistor BJT.

第3圖為本發明電源供應器100中雙極接面電晶體BJT運作時相關電壓和電流之示意圖。V_BE代表基極-射極電壓，V_BC代表基極-集極電壓，V_CE代表集極-射極電壓，I_B代表基極電流，而流經其集極和射極之間的電流即為補償電流I_C。如相關領域具備通常知識者皆知，依據所加偏壓(基極-射極電壓V_BE和基極-集極電壓V_BC)雙極接面電晶體BJT可在飽和區、主動區或截止區工作。在飽和區內V_BE和V_BC均為順向偏壓，集極和射極之間的電阻非常小，此時雙極接面電晶體BJT可視為短路，而補償電流I_C會為維持在固定的最大值。在截止區內V_BE和V_BC均為逆向偏壓，集極和射極之間的電阻非常大，此時雙極接面電晶體BJT可視為開路(I_C=0)。在主動區內V_BE為順向偏壓而V_BC為逆向偏壓，電流I_C之值會隨著基極電流I_B而變化(I_C=β I_B)，此時雙極接面電晶體BJT可視為增益值為β之訊號放大器。 FIG. 3 is a schematic diagram of the related voltage and current during the operation of the bipolar junction transistor BJT in the power supply 100 of the present invention. V _BE stands for base-emitter voltage, V _BC stands for base-collector voltage, V _CE stands for collector-emitter voltage, I _B stands for base current, and the current flowing between its collector and emitter It is the compensation current I _C. As known to those with general knowledge in the relevant field, the bipolar junction transistor BJT can be in the saturation zone, active zone or cut-off _{depending on the applied bias voltage (base-emitter voltage V BE} and base-collector voltage V _BC) Area work. In the saturation region, V _BE and V _BC are both forward biased, and the resistance between the collector and the emitter is very small. At this time, the bipolar junction transistor BJT can be regarded as a short circuit, and the compensation current I _C will be maintained at Fixed maximum value. In the cut-off region, V _BE and V _BC are both reverse biased, and the resistance between the collector and the emitter is very large. At this time, the bipolar junction transistor BJT can be regarded as an open circuit (I _C =0). In the active area, V _BE is forward bias and V _BC is reverse bias. _{The value of current I C} will vary with base current I _B (I _C = β I _B ). At this time, the bipolar junction current The crystal BJT can be regarded as a signal amplifier with a gain of β.

在本發明中，雙極接面電晶體BJT會操作在主動區，透過控制電壓V_BE之值使其維持在順向導通，就能穩定控制流經線性光耦合器PC內部發光二極體22的補償電流I_C，進而穩定感應至線性光耦合器PC中光敏電晶體22之回授電流I_FB和在回授電容C_FB上建立之回授電壓V_FB。 In the present invention, the bipolar junction transistor BJT will operate in the active region. By controlling _{the value of the voltage V BE} to maintain it in forward conduction, the light-emitting diode 22 flowing through the linear optocoupler PC can be controlled stably. compensation current I _C, so as to stabilize the induced linear photocoupler PC to the photosensitive transistor 22 in the feedback current I _FB and the feedback capacitor C _FB establishing the feedback voltage V _FB.

為了說明目的，假設輸出電壓V_OUT之值介於一上限值V_MAX和一下限值V_MIN之間，接下來針對輸出電壓V_OUT具上限值V_MAX和下限值V_MIN的兩種情況來說明本發明電源供應器100之運作。第4圖為本發明穩壓補償電路30在輸出電壓V_OUT具下限值V_MIN運作時相關電壓和電流之示意圖。第5圖為本發明穩壓補償電路30在輸出電壓V_OUT具上限值V_MAX運作時相關電壓和電流之示意圖。 For the purpose of illustration, suppose _{the value of the output voltage V OUT} is between an upper limit value V _MAX and a lower limit value V _MIN . Next, there are two types of output voltage V _{OUT: an} upper limit value V _MAX and a lower limit value V _MIN. The situation illustrates the operation of the power supply 100 of the present invention. FIG. 4 is a schematic diagram of the relevant voltage and current when the _{output voltage V OUT} has a lower limit value V _MIN when the voltage stabilizing compensation circuit 30 of the present invention is operating. FIG. 5 is a schematic diagram of the relevant voltage and current when the _{output voltage V OUT} has an upper limit value V _MAX when the voltage stabilizing compensation circuit 30 of the present invention is operating.

如第4圖所示，當V_OUT=V_MIN時稽納二極體ZD無法被崩潰，因此可視為開路。此時輸出電壓V_OUT和穩壓器TL跨壓V_KA之間的壓差(V_OUT-V_KA)會跨在電阻R1、電阻R2和電阻R3上(輸出電壓V_OUT跨壓V_KA之間的訊號路徑由箭頭表示)，而雙極接面電晶體BJT之基極-射極電壓V_BE由電阻R2上建立的電壓來提供，其中V_BE=(V_OUT-V_KA)*R2/(R1+R2+R3)。透過選擇電阻R1-R3之電阻值，可使在電阻R2上建立之基極-射極電壓V_BE大於將雙極接面電晶體BJT之BE接面維持在順向偏壓所需之電壓V_{BE_MAX}，如此即能建立一穩定的基極電流I_B以穩定控制流經線性光耦合器PC內部發光二極體22的補償電流I_C，進而穩定感應至線性光耦合器PC中光敏電晶體22之回授電流I_FB和在回授電容C_FB上建立之回授電壓V_FB。 As shown in Figure 4, when V _OUT =V _MIN , the ZD cannot be collapsed, so it can be regarded as an open circuit. At this time, the voltage difference between the _{output voltage V OUT} and the voltage across the regulator TL V _KA _{(V OUT} -V _KA ) will be across the resistor R1, resistor R2, and resistor R3 (between the output voltage V _{OUT and the} voltage V _KA The signal path of BJT is indicated by the arrow), and the base-emitter voltage V _{BE of the} bipolar junction transistor BJT is provided by the voltage established on the resistor R2, where V _BE =(V _OUT -V _KA )*R2/( R1+R2+R3). By selecting the resistance values of resistors R1-R3, the base-emitter voltage V _BE established on resistor R2 can be greater than the voltage V required to maintain the BE junction of the bipolar junction transistor BJT at the forward bias voltage. _{BE_MAX} , in this way, a stable base current I _B _{can be established to stably control the compensation current I C} flowing through the light-emitting diode 22 in the linear optocoupler PC, and then stably induce the photosensitive transistor 22 in the linear optocoupler PC the feedback current I _FB and the feedback capacitor C _FB establishing the feedback voltage V _FB.

如第5圖所示，當V_OUT=V_MAX時稽納二極體ZD會崩潰，因此可視為短路(輸出電壓V_OUT跨壓V_KA之間的訊號路徑由箭頭表示)。此時稽納二極體ZD的崩潰電壓V_ZD會跨在電阻R2和電阻R3上，而雙極接面電晶體BJT之基極-射極電壓V_BE由電阻R2上建立的電壓來提供，其中V_BE=V_ZD*R2/(R2+R3)。透過選擇電阻R2-R3之電阻值和稽納二極體ZD之崩潰電壓，可使在電阻R2上建立之基極-射極電壓V_BE大於將雙極接面電晶體BJT之BE接面維持在順向偏壓所需之電壓V_{BE_MAX}，如此即能建立一穩定的基極電流I_B以穩定控制流經線性光耦合器PC內部發光二極體22的補償電流I_C，進而穩定感應至線性光耦合器PC中光敏電晶體22之回授電流I_FB和在回授電容C_FB上建立之回授電壓V_FB。 As shown in Fig. 5, when V _OUT =V _MAX , the sensing diode ZD will collapse, so it can be regarded as a short circuit ( _{the signal path between the output voltage V OUT and the} voltage V _KA is indicated by the arrow). At this time, the breakdown voltage V _{ZD of the sensing} diode ZD will cross the resistor R2 and the resistor R3, and the base-emitter voltage V _{BE of the} bipolar junction transistor BJT is provided by the voltage established on the resistor R2. Where V _BE =V _ZD *R2/(R2+R3). By selecting the resistance value of the resistor R2-R3 and the breakdown voltage of the diode ZD, the base-emitter voltage V _BE established on the resistor R2 can be greater than the BE junction of the bipolar junction transistor BJT. _{At the voltage V BE_MAX} required by the forward bias, a stable base current I _B _{can be established to stably control the compensation current I C} flowing through the light-emitting diode 22 inside the linear optocoupler PC, and then stably sense to linear photocoupler PC in the light-sensitive transistor 22 of the feedback current I _FB and the feedback capacitor C _FB establishing the feedback voltage V _FB.

在穩壓補償電路30中，抗雜訊電容C_X之第一端耦接至輸出電壓V_OUT，抗雜訊電容CX之第二端耦接至抗雜訊二極體D_X之陽極，而雜訊二極體D_X之陰極耦接至稽納二極體ZD之陽極。在穩壓補償電路30的運作期間，抗雜訊電容C_X和抗雜訊二極體D_X可防止補償電容C_C和穩壓器TL去影響其穩定補償電流I_C之功能，同時也防止穩定補償電流I_C之功能去影響到補償電容C_C和穩壓器TL的運作。 In the voltage stabilizing compensation circuit 30, _{the first end of the anti-noise capacitor C X} is coupled to the output voltage V _OUT , the second end of the anti-noise capacitor CX is coupled to the anode of the _{anti-noise diode D X, and} The cathode of the noise diode D _X is coupled to the anode of the sensor diode ZD. During the operation of the voltage stabilizing compensation circuit 30, the anti-noise capacitor C _X and the anti-noise diode D _{X can} prevent the compensation capacitor C _C and the voltage regulator TL from affecting its function of stabilizing the compensation current I _C , and also prevent The function of stabilizing the compensation current I _C affects the operation of the compensation capacitor C _C and the voltage regulator TL.

在本發明中，回授電容C_FB之電容值/耐壓可為10pF/50V(誤差±10%)，輸出電容C_OUT之電容值可為680μF(誤差±10%)，抗雜訊電容C_X之電容值/耐壓可為1nF/50V(誤差±10%)，補償電容C_C之電容值/耐壓可為1.5nF/50V(誤差±10%)，電阻R1之電阻值可為49.9Ω(誤差±1%)，電阻R2之電阻值可為8.2Ω(誤差±1%)，電阻R3之電阻值可為2.32Ω(誤差±1%)，分壓電阻R_D1之電阻值可為150KΩ(誤差±5%)，分壓電阻R_D2之電阻值可為10.3KΩ(誤差±5%)，稽納二極體ZD之崩潰電壓可介於7.8V和 8.6V，電源供應器100之輸出電壓V_OUT可為40V(誤差±5%)，穩壓器TL之跨壓V_KA可為2A(誤差±5%)，維持雙極接面電晶體BJT之BE接面順向偏壓所需之電壓V_{BE_MAX}可為0.7V，雙極接面電晶體BJT之電流增益β可為200，回授電路20和穩壓補償電路30之相位邊限(phase margin)可大於45度，而回授電路20和穩壓補償電路30之增益邊限(gain margin)可小於-10dB。然而，上述元件之實作方式和規格並不限定本發明之範疇。 In the present invention, _{the capacitance value/withstand voltage of the feedback capacitor C FB} can be 10pF/50V (error ±10%), _{the capacitance value of the output capacitor C OUT} can be 680μF (error ±10%), and the anti-noise capacitor C _{The capacitance value/withstand voltage of X} can be 1nF/50V (error ±10%), _{the capacitance value/withstand voltage of compensation capacitor C C} can be 1.5nF/50V (error ±10%), and the resistance value of resistor R1 can be 49.9 Ω (error ±1%), the resistance value of resistor R2 can be 8.2Ω (error ±1%), the resistance value of resistor R3 can be 2.32Ω (error ±1%), the resistance value of _{voltage divider R D1 can be} 150KΩ (error ±5%), _{the resistance value of the voltage divider R D2} can be 10.3KΩ (error ±5%), the breakdown voltage of the sensing diode ZD can be between 7.8V and 8.6V, the power supply 100 The output voltage V _OUT can be 40V (error ±5%), and the voltage regulator TL's cross voltage V _KA can be 2A (error ±5%), maintaining the forward bias of the BE junction of the bipolar junction transistor BJT The required voltage V _{BE_MAX} can be 0.7V, the current gain β of the bipolar junction transistor BJT can be 200, the phase margin of the feedback circuit 20 and the voltage regulator compensation circuit 30 can be greater than 45 degrees, and The gain margin of the power supply circuit 20 and the voltage regulator compensation circuit 30 can be less than -10dB. However, the implementation methods and specifications of the above components do not limit the scope of the present invention.

綜上所述，本發明提供一種具有穩定補償電流設計之電源供應器，將穩壓補償電路之雙極接面電晶體操作在主動區以穩定補償電流。當在相同輸出功率的條件下將輸出電壓提高以降低熱損耗時，穩壓補償電路可提供較大的回授補償範圍，進而改善輸出端震盪的問題。以上所述僅為本發明之較佳實施例，凡依本發明申請專利範圍所做之均等變化與修飾，皆應屬本發明之涵蓋範圍。 In summary, the present invention provides a power supply with a stable compensation current design, which operates the bipolar junction transistor of the stabilized compensation circuit in the active area to stabilize the compensation current. When the output voltage is increased under the same output power condition to reduce heat loss, the voltage regulator compensation circuit can provide a larger feedback compensation range, thereby improving the problem of output end oscillation. The foregoing descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made in accordance with the scope of the patent application of the present invention shall fall within the scope of the present invention.

10:脈衝寬度調變積體電路 10: Pulse width modulation integrated circuit

20:回授電路 20: Feedback circuit

22:發光二極體 22: Light-emitting diode

24:光敏電晶體 24: Photosensitive transistor

30:穩壓補償電路 30: Voltage regulator compensation circuit

100:電源供應器 100: power supply

NP1:初級側繞組和匝數 NP1: Primary side winding and number of turns

NS1:次級側繞組和匝數 NS1: Secondary winding and number of turns

GND1、GND2:接地電位 GND1, GND2: ground potential

TR:變壓器 TR: Transformer

Q1:功率開關 Q1: Power switch

C_OUT:輸出電容 C _OUT : output capacitance

D_OUT:輸出二極體 D _OUT : output diode

C_FB:回授電容 C _FB : feedback capacitor

C_C:補償電容 C _C : Compensation capacitor

C_X:抗雜訊電容 C _X : Anti-noise capacitance

R_D1、R_D2:分壓電阻 R _D1 , R _D2 : voltage divider resistance

BJT:雙極接面電晶體 BJT: Bipolar junction transistor

R1-R3:電阻 R1-R3: resistance

ZD:稽納二極體 ZD: Sensing diode

D_X:抗雜訊二極體 D _X : Anti-noise diode

PC:線性光耦合器 PC: Linear Optocoupler

TL:穩壓器 TL: voltage regulator

K:陰極端 K: cathode end

A:陽極端 A: Anode

R:參考端 R: Reference terminal

V_IN:輸入電壓 V _IN : Input voltage

V_OUT:輸出電壓 V _OUT : output voltage

V_FB:回授電壓 V _FB : Feedback voltage

V_REF:參考電壓 V _REF : Reference voltage

V_KA:穩壓器跨壓 V _KA : Voltage regulator cross voltage

I_IN:輸入電流 I _IN : Input current

I_OUT:輸出電壓 I _OUT : output voltage

GD1:控制訊號 GD1: Control signal

V_BE:基極-射極電壓 V _BE : base-emitter voltage

V_BC:基極-集極電壓 V _BC : base-collector voltage

V_CE:代表集極-射極電壓 V _CE : stands for collector-emitter voltage

I_C:補償電流 I _C : Compensation current

I_B:基極電流 I _B : base current

Claims

一種具穩定補償電流設計之電源供應器，其包含：一輸入端，用來接收一輸入電壓；一輸出端，用來輸出該輸出電壓；一變壓器，用來將該輸入電壓從一初級側感應至一次級側以供應該輸出電壓；一回授電路，用來依據該輸出電壓來提供一補償電流，並將該補償電流轉換成一回授電壓，該回授電路包含：一第一分壓電阻和一第二分壓電阻，串聯於該輸出端和一接地電位之間，用來分壓該輸出電壓以提供一參考電壓；一穩壓器，其包含：一陰極端；一陽極端，耦接至該接地電位；以及一參考端，耦接於該第一分壓電阻和該第二分壓電阻以接收該參考電壓；一補償電容，耦接於該穩壓器之該陰極端和該參考端之間；一線性光耦合器，用來將相關該輸出電壓變化量之一電能轉換成一光能，再將該光能轉換成一回授電流；以及一回授電容，用來儲存該回授電流之能量以提供該回授電壓；一穩壓補償電路，其包含一雙極接面電晶體，該雙極接面電晶體操作在一主動區以穩定該補償電流；一脈衝寬度調變積體電路，用來依據該回授電壓來提供一控制訊號，並調整該控制訊號之工作週期；以及一功率開關，用來依據該控制訊號而選擇性地導通或截止，以調節該變壓器從該初級側感應至該次級側之能量。 A power supply with a stable compensation current design, comprising: an input terminal for receiving an input voltage; an output terminal for outputting the output voltage; a transformer for sensing the input voltage from a primary side To the secondary side to supply the output voltage; a feedback circuit for providing a compensation current according to the output voltage and converting the compensation current into a feedback voltage, the feedback circuit includes: a first voltage divider resistor And a second voltage divider resistor, connected in series between the output terminal and a ground potential, used to divide the output voltage to provide a reference voltage; a voltage regulator, which includes: a cathode terminal; an anode terminal, coupled To the ground potential; and a reference terminal, coupled to the first voltage dividing resistor and the second voltage dividing resistor to receive the reference voltage; a compensation capacitor, coupled to the cathode terminal of the voltage regulator and the reference Between terminals; a linear optocoupler, used to convert an electrical energy related to the output voltage change into a light energy, and then convert the light energy into a feedback current; and a feedback capacitor to store the feedback The energy of the current provides the feedback voltage; a voltage stabilizing compensation circuit including a bipolar junction transistor that operates in an active area to stabilize the compensation current; a pulse width modulation product The body circuit is used to provide a control signal according to the feedback voltage and adjust the duty cycle of the control signal; and a power switch is used to selectively turn on or off according to the control signal to adjust The transformer induces energy from the primary side to the secondary side.

如請求項1所述之電源供應器，其中該線性光耦合器包含：一發光二極體，設置在該次級側，用來感應該輸出電壓之變化量以產生該電能；以及一光敏電晶體，設置在該初級側，用來將該光能轉換成該回授電流。 The power supply of claim 1, wherein the linear optocoupler includes: a light emitting diode disposed on the secondary side for sensing a change in the output voltage to generate the electrical energy; and a photosensitive cell The crystal is arranged on the primary side to convert the light energy into the feedback current.

如請求項2所述之電源供應器，其中該穩壓補償電路包含：一第一電阻；一第二電阻；一第三電阻；一雙極接面電晶體，其包含：一集極，耦接至該發光二極體之陰極；一射極，透過該第三電阻耦接至該穩壓器之該陰極端；以及一基極，透過該第一電阻耦接至該輸出端，其中該第二電阻耦接於該集極和該基極之間；以及一稽納二極體，其包含：一陽極，耦接至該穩壓器之該陰極端；以及一陰極，耦接至該基極。 The power supply of claim 2, wherein the voltage stabilization compensation circuit includes: a first resistor; a second resistor; a third resistor; a bipolar junction transistor, which includes: a collector, a coupling Connected to the cathode of the light-emitting diode; an emitter coupled to the cathode terminal of the voltage regulator through the third resistor; and a base coupled to the output terminal through the first resistor, wherein the The second resistor is coupled between the collector and the base; and an audit diode, which includes: an anode coupled to the cathode terminal of the voltage regulator; and a cathode coupled to the Base.

如請求項3所述之電源供應器，其中該穩壓補償電路另包含：一抗雜訊電容，其包含：一第一端，耦接至該輸出端；以及一第二端；以及一抗雜訊二極體，其包含：一陽極，耦接至該抗雜訊電容之該第二端；以及一陰極，耦接至該稽納二極體之該陽極。 The power supply according to claim 3, wherein the voltage stabilization compensation circuit is additionally included Including: an anti-noise capacitor, which includes: a first end coupled to the output end; and a second end; and an anti-noise diode, including: an anode coupled to the anti-noise The second end of the communication capacitor; and a cathode coupled to the anode of the audit diode.

如請求項1所述之電源供應器，其中該穩壓補償電路包含：一第一電阻；一第二電阻；一第三電阻；一雙極接面電晶體，其包含：一集極，用來接收該補償電流；一射極，透過該第三電阻耦接至該回授電路；以及一基極，透過該第一電阻耦接至該輸出端，其中該第二電阻耦接於該集極和該基極之間；以及一稽納二極體，其包含：一陽極，透過該第三電阻耦接至該射極；以及一陰極，耦接至該基極。 The power supply of claim 1, wherein the voltage stabilization compensation circuit includes: a first resistor; a second resistor; a third resistor; a bipolar junction transistor, which includes: a collector, To receive the compensation current; an emitter coupled to the feedback circuit through the third resistor; and a base coupled to the output terminal through the first resistor, wherein the second resistor is coupled to the set Between the electrode and the base; and an audit diode, which includes: an anode coupled to the emitter through the third resistor; and a cathode coupled to the base.

如請求項5所述之電源供應器，其中該穩壓補償電路另包含：一抗雜訊電容，其包含：一第一端，耦接至該輸出端；以及一第二端；以及一抗雜訊二極體，其包含：一陽極，耦接至該抗雜訊電容之該第二端；以及一陰極，耦接至該稽納二極體之該陽極。 The power supply according to claim 5, wherein the voltage stabilization compensation circuit further includes: An anti-noise capacitor including: a first terminal coupled to the output terminal; and a second end; and an anti-noise diode including: an anode coupled to the anti-noise capacitor The second end; and a cathode, coupled to the anode of the audit diode.

如請求項4所述之電源供應器，其中：該輸出電壓之值介於一上限值和一下限值之間；當輸出電壓之值為該下限值時，該稽納二極體未崩潰，而該輸出電壓和該回授電路之間的壓差係跨在該第一電阻、該第二電阻和該第三電阻上；且該第二電阻之跨壓大於將該雙極接面電晶體之一基極-射極接面維持在順向偏壓所需之電壓值。 The power supply of claim 4, wherein: the value of the output voltage is between an upper limit and a lower limit; when the value of the output voltage is the lower limit, the audit diode is not Collapse, and the voltage difference between the output voltage and the feedback circuit is across the first resistor, the second resistor, and the third resistor; and the voltage across the second resistor is greater than the bipolar junction The base-emitter junction of one of the transistors is maintained at the voltage required by the forward bias.

如請求項4所述之電源供應器，其中：該輸出電壓之值介於一上限值和一下限值之間；當輸出電壓之值為該上限值時，該稽納二極體為崩潰，而該稽納二極體之一崩潰電壓係跨在該第二電阻和該第三電阻上；且該第二電阻之跨壓大於將該雙極接面電晶體之一基極-射極接面維持在順向偏壓所需之電壓值。 The power supply of claim 4, wherein: the value of the output voltage is between an upper limit and a lower limit; when the value of the output voltage is the upper limit, the audit diode is The breakdown voltage of the sensing diode is across the second resistor and the third resistor; and the voltage across the second resistor is greater than the base-emitter of the bipolar junction transistor. The pole junction is maintained at the voltage value required by the forward bias.

一種具穩定補償電流設計之電源供應器，其包含：一輸入端，用來接收一輸入電壓；一輸出端，用來輸出該輸出電壓；一變壓器，用來將該輸入電壓從一初級側感應至一次級側以供應該輸出電壓；一回授電路，用來依據該輸出電壓來提供一補償電流，並將該補償電流轉換成一回授電壓；一穩壓補償電路，其包含：一第一電阻；一第二電阻；一第三電阻；一雙極接面電晶體，其操作在一主動區以穩定該補償電流，且包含：一集極，用來接收該補償電流；一射極，透過該第三電阻耦接至該回授電路；以及一基極，透過該第一電阻耦接至該輸出端，其中該第二電阻耦接於該集極和該基極之間；以及一稽納二極體，其包含：一陽極，透過該第三電阻耦接至該射極；以及一陰極，耦接至該基極；一脈衝寬度調變積體電路，用來依據該回授電壓來提供一控制訊號，並調整該控制訊號之工作週期；以及一功率開關，用來依據該控制訊號而選擇性地導通或截止，以調節該變壓器從該初級側感應至該次級側之能量。 A power supply with a stable compensation current design, comprising: an input terminal for receiving an input voltage; An output terminal is used to output the output voltage; a transformer is used to induce the input voltage from a primary side to a secondary side to supply the output voltage; a feedback circuit is used to provide a compensation according to the output voltage And convert the compensation current into a feedback voltage; a voltage stabilization compensation circuit, which includes: a first resistor; a second resistor; a third resistor; a bipolar junction transistor, which operates in an active The zone stabilizes the compensation current and includes: a collector for receiving the compensation current; an emitter coupled to the feedback circuit through the third resistor; and a base coupled to the first resistor To the output terminal, wherein the second resistor is coupled between the collector and the base; and an audit diode, which includes: an anode coupled to the emitter through the third resistor; and A cathode is coupled to the base; a pulse width modulation integrated circuit is used to provide a control signal according to the feedback voltage and adjust the duty cycle of the control signal; and a power switch is used according to the The control signal is selectively turned on or off to adjust the energy induced by the transformer from the primary side to the secondary side.

如請求項1和9中任一項所述之電源供應器，其另包含：一輸出電容，耦接於該輸出端和一接地電位之間；以及一輸出二極體，其陽極耦接於該次級側，而其陰極耦接於該輸出端。 The power supply according to any one of claims 1 and 9, which further includes: An output capacitor is coupled between the output terminal and a ground potential; and an output diode, the anode of which is coupled to the secondary side, and the cathode of which is coupled to the output terminal.