TWI817460B

TWI817460B - Power supply device

Info

Publication number: TWI817460B
Application number: TW111115723A
Authority: TW
Inventors: 詹子增
Original assignee: 宏碁股份有限公司
Priority date: 2022-04-26
Filing date: 2022-04-26
Publication date: 2023-10-01
Also published as: TW202343196A

Abstract

A power supply device provided. The power supply device includes a primary side circuit, a secondary side circuit, a controller, and a feedback and compensation circuit. The secondary side circuit generates a sensing voltage value according to an output current value. The feedback and compensation circuit provides a loop gain. When the sensing voltage value is greater than or equal to a reference value, the feedback and compensation circuit causes the controller to control the primary side circuit, so that the secondary side circuit provides an output voltage. When the sensing voltage value is less than the reference value, the feedback and compensation circuit causes the controller to perform a frequency reduction operation on the primary side circuit, and reduces the loop gain to reduce the voltage value of the output voltage.

Description

電源供應裝置power supply unit

本發明是有關於一種電源供應裝置，且特別是有關於一種能夠在低負載條件下符合節能要求的電源供應裝置。The present invention relates to a power supply device, and in particular, to a power supply device that can meet energy saving requirements under low load conditions.

為了在降低耗能產品對環境的衝擊及影響，歐盟執行委員會節能化設計指令（2005/32/EC）制訂了一規範以規定住宅、第三級產業及工業界耗能產品的節能要求。In order to reduce the impact and impact of energy-consuming products on the environment, the European Commission's Energy-Saving Design Directive (2005/32/EC) has formulated a specification to stipulate energy-saving requirements for energy-consuming products in residential, tertiary industries and industrial sectors.

關於電源供應裝置，為了能在低負載狀態（如，閒置狀態或極輕載狀態）下達到降低損耗並節能的目的，電源供應裝置採用降頻方式（如，突衝模式（Burst mode））以降低在低負載條件下的切換損失。然而，在輸出功率較大的機種，仍會因能量較大而有著損耗下降之極限。也就是說，在低負載條件下，輸出功率在具有下降限制下，輸出功率較大的機種仍無法符合歐盟執行委員會節能化設計指令的節能要求（如Lot 7外接式電源供應器EC 278/2009）。Regarding the power supply device, in order to reduce losses and save energy in a low load state (such as idle state or very light load state), the power supply device adopts a frequency reduction method (such as burst mode) to Reduce switching losses under low load conditions. However, in models with larger output power, there is still a limit to the loss reduction due to the larger energy. That is to say, under low load conditions, the output power has a reduction limit, and models with larger output power still cannot meet the energy saving requirements of the European Commission's Energy Saving Design Directive (such as Lot 7 external power supplies EC 278/2009 ).

本發明提供一種電源供應裝置，能夠在低負載條件下符合節能要求。The invention provides a power supply device that can meet energy saving requirements under low load conditions.

本發明的電源供應裝置包括電源轉換器、控制器以及回授與補償電路。電源轉換器包括初級側電路以及次級側電路。次級側電路依據輸出電流值產生感測電壓值。控制器耦接於初級側電路。回授與補償電路耦接於次級側電路以及控制器。回授與補償電路提供回路增益。當感測電壓值大於或等於參考值時，回授與補償電路使控制器來控制初級側電路，從而使次級側電路提供輸出電壓。當感測電壓值小於參考值時，回授與補償電路使控制器對初級側電路進行降頻操作，降低回路增益以降低輸出電壓的電壓值。The power supply device of the present invention includes a power converter, a controller, and a feedback and compensation circuit. The power converter includes a primary side circuit and a secondary side circuit. The secondary side circuit generates a sensing voltage value based on the output current value. The controller is coupled to the primary side circuit. The feedback and compensation circuit is coupled to the secondary side circuit and the controller. Feedback and compensation circuitry provide loop gain. When the sensed voltage value is greater than or equal to the reference value, the feedback and compensation circuit enables the controller to control the primary side circuit, thereby causing the secondary side circuit to provide an output voltage. When the sensed voltage value is less than the reference value, the feedback and compensation circuit causes the controller to perform a frequency reduction operation on the primary side circuit, reducing the loop gain to reduce the voltage value of the output voltage.

基於上述，當感測電壓值小於參考值時，回授與補償電路降低電源供應裝置的回路增益以降低輸出電壓的電壓值。因此，輸出功率能夠被下降。如此一來，在低負載條件下，電源供應裝置能夠符合滿足現行規範的節能要求。Based on the above, when the sensed voltage value is less than the reference value, the feedback and compensation circuit reduces the loop gain of the power supply device to reduce the voltage value of the output voltage. Therefore, the output power can be reduced. In this way, under low load conditions, the power supply device can meet the energy saving requirements of current regulations.

為讓本發明的上述特徵和優點能更明顯易懂，下文特舉實施例，並配合所附圖式作詳細說明如下。In order to make the above-mentioned features and advantages of the present invention more obvious and easy to understand, embodiments are given below and described in detail with reference to the accompanying drawings.

本發明的部份實施例接下來將會配合附圖來詳細描述，以下的描述所引用的元件符號，當不同附圖出現相同的元件符號將視為相同或相似的元件。這些實施例只是本發明的一部份，並未揭示所有本發明的可實施方式。更確切的說，這些實施例只是本發明的專利申請範圍中的範例。Some embodiments of the present invention will be described in detail with reference to the accompanying drawings. The component symbols cited in the following description will be regarded as the same or similar components when the same component symbols appear in different drawings. These embodiments are only part of the present invention and do not disclose all possible implementations of the present invention. Rather, these embodiments are only examples within the scope of the patent application of the invention.

請參考圖1，圖1是依據本發明第一實施例所繪示的電源供應裝置的示意圖。在本實施例中，電源供應裝置100包括電源轉換器CR、控制器130以及回授與補償電路140。電源轉換器CR至少包括初級側電路110、次級側電路120。控制器130耦接於初級側電路110。控制器130對初級側電路110進行控制，使得次級側電路120提供輸出電壓VO。在本實施例中，電源轉換器CR還包括變壓器TR。因此，基於控制器130的控制，變壓器TR、初級側電路110以及次級側電路120共同對輸入電壓VI進行轉換以產生輸出電壓VO。輸入電壓VI可以是被整流的電壓訊號。在本實施例中，次級側電路120還依據輸出電流值IO產生感測電壓值VS。輸出電流值IO正相關於感測電壓值VS。Please refer to FIG. 1 , which is a schematic diagram of a power supply device according to a first embodiment of the present invention. In this embodiment, the power supply device 100 includes a power converter CR, a controller 130 and a feedback and compensation circuit 140 . Power converter CR includes at least a primary side circuit 110 and a secondary side circuit 120 . The controller 130 is coupled to the primary side circuit 110 . The controller 130 controls the primary side circuit 110 so that the secondary side circuit 120 provides the output voltage VO. In this embodiment, the power converter CR also includes a transformer TR. Therefore, based on the control of the controller 130, the transformer TR, the primary side circuit 110 and the secondary side circuit 120 jointly convert the input voltage VI to generate the output voltage VO. The input voltage VI may be a rectified voltage signal. In this embodiment, the secondary side circuit 120 also generates the sensing voltage value VS according to the output current value IO. The output current value IO is directly related to the sensing voltage value VS.

在本實施例中，回授與補償電路140耦接於次級側電路120以及控制器130。回授與補償電路140提供回路增益LG。回授與補償電路140會接收來自於次級側電路120的感測電壓值VS，並且對感測電壓值VS進行判斷。當感測電壓值VS大於或等於參考值VR時，這表示輸出電流值IO高於一電流值準位。電源供應裝置100正在對一負載進行常規的供電。也就是說，電源供應裝置100處於供電狀態。因此，回授與補償電路140使控制器130來控制初級側電路110，從而使次級側電路120提供輸出電壓VO。In this embodiment, the feedback and compensation circuit 140 is coupled to the secondary side circuit 120 and the controller 130 . Feedback and compensation circuit 140 provides loop gain LG. The feedback and compensation circuit 140 receives the sensing voltage value VS from the secondary side circuit 120 and determines the sensing voltage value VS. When the sensing voltage value VS is greater than or equal to the reference value VR, it means that the output current value IO is higher than a current value level. The power supply device 100 is providing regular power supply to a load. That is, the power supply device 100 is in a power supply state. Therefore, the feedback and compensation circuit 140 enables the controller 130 to control the primary side circuit 110 so that the secondary side circuit 120 provides the output voltage VO.

在另一方面，當感測電壓值VS小於參考值VR時，這表示輸出電流值IO低於電流值準位。電源供應裝置100停止對負載進行常規的供電。也就是說，電源供應裝置100處於低負載狀態。低負載狀態可以是閒置狀態或極輕載狀態。因此，回授與補償電路140會使控制器130對初級側電路110進行降頻操作（如，進入突衝模式）。因此，初級側電路110的切換功耗能夠被下降。此外，回授與補償電路140還降低回路增益LG以降低輸出電壓VO的電壓值。On the other hand, when the sensed voltage value VS is less than the reference value VR, it means that the output current value IO is lower than the current value level. The power supply device 100 stops providing regular power supply to the load. That is, the power supply device 100 is in a low load state. The low load state can be an idle state or a very light load state. Therefore, the feedback and compensation circuit 140 causes the controller 130 to perform a down-frequency operation on the primary side circuit 110 (eg, enter a burst mode). Therefore, the switching power consumption of the primary side circuit 110 can be reduced. In addition, the feedback and compensation circuit 140 also reduces the loop gain LG to reduce the voltage value of the output voltage VO.

在此值得一提的是，當感測電壓值VS小於參考值VR時，回授與補償電路140降低電源供應裝置100的回路增益LG以降低輸出電壓VO的電壓值。因此，輸出功率能夠大幅被下降。如此一來，在低負載狀態下，電源供應裝置100能夠符合滿足現行規範的節能要求（如Lot 7外接式電源供應器EC 278/2009）。It is worth mentioning here that when the sensed voltage value VS is less than the reference value VR, the feedback and compensation circuit 140 reduces the loop gain LG of the power supply device 100 to reduce the voltage value of the output voltage VO. Therefore, the output power can be significantly reduced. In this way, under low load conditions, the power supply device 100 can meet the energy saving requirements of current regulations (such as Lot 7 external power supply EC 278/2009).

以本實施例為例，變壓器TR具有初級側繞組NP以及次級側繞組NS。初級側電路110耦接於初級側繞組NP。次級側電路120耦接於次級側繞組NS。初級側電路110包括激磁電感器LM以及功率開關Q1。激磁電感器LM與初級側繞組NP彼此並聯耦接。激磁電感器LM的第一端接收輸入電壓VI。功率開關Q1的第一端耦接於激磁電感器LM的第二端。功率開關Q1的第二端耦接於接地端GND1。功率開關Q1的控制端耦接於控制器130。功率開關Q1的控制端接收控制器130所提供的切換控制訊號GD。次級側電路120包括輸出二極體DO、輸出電容器CO以及感測電阻器RS。輸出二極體DO的陽極耦接於次級側繞組NS的第一端。輸出二極體DO的陰極作為次級側電路120的輸出端。輸出電容器CO的第一端耦接於輸出二極體DO的陰極。感測電阻器RS耦接於輸出電容器CO的第二端與接地端GND2之間。次級側電路120會將流經感測電阻器RS的輸出電流的輸出電流值IO轉換為感測電壓值VS。Taking this embodiment as an example, the transformer TR has a primary side winding NP and a secondary side winding NS. The primary side circuit 110 is coupled to the primary side winding NP. The secondary circuit 120 is coupled to the secondary winding NS. Primary side circuit 110 includes magnetizing inductor LM and power switch Q1. The magnetizing inductor LM and the primary side winding NP are coupled in parallel to each other. The first terminal of the magnetizing inductor LM receives the input voltage VI. The first terminal of the power switch Q1 is coupled to the second terminal of the magnetizing inductor LM. The second terminal of the power switch Q1 is coupled to the ground terminal GND1. The control terminal of the power switch Q1 is coupled to the controller 130 . The control terminal of the power switch Q1 receives the switching control signal GD provided by the controller 130 . The secondary side circuit 120 includes an output diode DO, an output capacitor CO, and a sensing resistor RS. The anode of the output diode DO is coupled to the first end of the secondary side winding NS. The cathode of the output diode DO serves as the output terminal of the secondary side circuit 120 . The first terminal of the output capacitor CO is coupled to the cathode of the output diode DO. The sensing resistor RS is coupled between the second terminal of the output capacitor CO and the ground terminal GND2. The secondary side circuit 120 converts the output current value IO of the output current flowing through the sensing resistor RS into a sensing voltage value VS.

本實施例的電源轉換器CR以具有變壓器TR的反馳式（flyback）轉換器，然本發明並不以此為限。在一些實施例中，電源轉換器CR可以是LLC轉換器。在一些實施例中，電源轉換器CR可以是非隔離式轉換器，如Buck-Boost轉換器。The power converter CR in this embodiment is a flyback converter with a transformer TR, but the invention is not limited thereto. In some embodiments, power converter CR may be an LLC converter. In some embodiments, the power converter CR may be a non-isolated converter, such as a Buck-Boost converter.

請參考圖2，圖2是依據本發明第二實施例所繪示的電源供應裝置的示意圖。在本實施例中，電源供應裝置200包括電源轉換器CR、控制器130以及回授與補償電路240。電源供應裝置100包括電源轉換器CR、控制器130以及回授與補償電路240。電源轉換器CR至少包括變壓器TR、初級側電路110、次級側電路120。回授與補償電路240包括回授電路241與判斷電路242。回授電路241依據輸出電壓VO的電壓值來提供回授訊號SFB。控制器130依據回授訊號SFB調節控制訊號GD的頻率。因此，在供電狀態中，輸出電壓VO的電壓值得以被穩定。Please refer to FIG. 2 , which is a schematic diagram of a power supply device according to a second embodiment of the present invention. In this embodiment, the power supply device 200 includes a power converter CR, a controller 130 and a feedback and compensation circuit 240 . The power supply device 100 includes a power converter CR, a controller 130 and a feedback and compensation circuit 240 . Power converter CR includes at least a transformer TR, a primary side circuit 110 and a secondary side circuit 120 . The feedback and compensation circuit 240 includes a feedback circuit 241 and a judgment circuit 242 . The feedback circuit 241 provides the feedback signal SFB according to the voltage value of the output voltage VO. The controller 130 adjusts the frequency of the control signal GD according to the feedback signal SFB. Therefore, in the power supply state, the voltage value of the output voltage VO can be stabilized.

判斷電路242對感測電壓值VS與參考值VR進行比較，當感測電壓值VS大於或等於參考值VR時，判斷電路242並不會降低回授與補償電路240內部的回路增益（如圖1所示的回路增益LG）。此外，輸出電壓VO的電壓值會被穩定。The judgment circuit 242 compares the sensed voltage value VS with the reference value VR. When the sensed voltage value VS is greater than or equal to the reference value VR, the judgment circuit 242 will not reduce the loop gain inside the feedback and compensation circuit 240 (as shown in the figure) The loop gain shown in 1 is LG). In addition, the voltage value of the output voltage VO will be stabilized.

在另一方面，當感測電壓值VS小於參考值VR時，判斷電路242會降低回授與補償電路240內部的回路增益。因此，輸出電壓VO會被降低。此外，當感測電壓值VS小於參考值VR時，判斷電路242還指示控制器130對初級側電路110進行降頻操作。On the other hand, when the sensed voltage value VS is less than the reference value VR, the judgment circuit 242 will reduce the loop gain inside the feedback and compensation circuit 240 . Therefore, the output voltage VO will be reduced. In addition, when the sensed voltage value VS is less than the reference value VR, the determination circuit 242 also instructs the controller 130 to perform a down-frequency operation on the primary side circuit 110 .

在本實施例中，回授電路241包括耦合電路2411、穩壓器2412、電阻器R1、分壓電阻器RB以及第一補償電路2413。耦合電路2411耦接於控制器130與次級側電路120之間。穩壓器2412的第一端耦接於耦合電路2411。穩壓器2412的第二端耦接於次級側電路120的參考低電壓（例如是接地端GND2）。穩壓器2412的參考端用以提供參考值VR。穩壓器2412依據輸出電壓VO的變化使耦合電路2411提供對應的回授訊號SFB。電阻器R1耦接於次級側電路120的輸出端與穩壓器2412的參考端之間。分壓電阻器RB耦接於穩壓器2412的參考端與穩壓器2412的第二端之間。In this embodiment, the feedback circuit 241 includes a coupling circuit 2411, a voltage regulator 2412, a resistor R1, a voltage dividing resistor RB, and a first compensation circuit 2413. The coupling circuit 2411 is coupled between the controller 130 and the secondary side circuit 120 . The first terminal of the voltage regulator 2412 is coupled to the coupling circuit 2411. The second terminal of the voltage regulator 2412 is coupled to the reference low voltage of the secondary side circuit 120 (for example, the ground terminal GND2). The reference terminal of the voltage regulator 2412 is used to provide a reference value VR. The voltage regulator 2412 causes the coupling circuit 2411 to provide the corresponding feedback signal SFB according to the change in the output voltage VO. Resistor R1 is coupled between the output terminal of secondary side circuit 120 and the reference terminal of voltage regulator 2412 . The voltage dividing resistor RB is coupled between the reference terminal of the voltage regulator 2412 and the second terminal of the voltage regulator 2412 .

在本實施例中，耦合電路2411可以是由光耦合器（如，元件PC817）來實現。穩壓器2412可以是由元件TL431來實現。耦合電路2411包括發光二極體以及耦合電晶體。發光二極體的陽極耦接於輸出電壓VO。發光二極體的陰極耦接於穩壓器2412的第一端。耦合電晶體耦接於控制器130與接地端GND1之間。在本實施例中，電阻器R1以及分壓電阻器RB會對輸出電壓VO的電壓值進行分壓以獲得輸出電壓VO的分壓值。穩壓器2412會接收分壓值並且將分壓值與參考值VR進行比較。當分壓值與參考值VR不相同時，穩壓器2412的第一端的電壓值會發生變化，進而影響發光二極體的發光結果。因此，耦合電晶體所產生的回授訊號SFB也會發生改變。舉例來說，當輸出電壓VO的電壓值上升時，穩壓器2412所接收到的分壓值會上升。因此，穩壓器2412的第一端的電壓值會被對應地降低。發光二極體的亮度會上升。因此，耦合電晶體所提供的回授訊號SFB的電流值會上升。進而影像回授與補償電路240內的電容器CB的充電結果。控制器130會依據電容器CB的充電結果來降低切換控制訊號GD的工作週期。因此，輸出電壓VO的電壓值會被下降。相似地，當輸出電壓VO的電壓值下降時，控制器130會上升切換控制訊號GD的工作週期。因此，輸出電壓VO的電壓值會被上升。因此，在供電狀態中，輸出電壓VO的電壓值能夠被穩定。In this embodiment, the coupling circuit 2411 may be implemented by an optical coupler (eg, component PC817). The voltage regulator 2412 may be implemented by component TL431. The coupling circuit 2411 includes a light emitting diode and a coupling transistor. The anode of the light-emitting diode is coupled to the output voltage VO. The cathode of the light emitting diode is coupled to the first terminal of the voltage regulator 2412 . The coupling transistor is coupled between the controller 130 and the ground terminal GND1. In this embodiment, the resistor R1 and the voltage dividing resistor RB divide the voltage value of the output voltage VO to obtain the divided voltage value of the output voltage VO. The voltage regulator 2412 receives the divided voltage value and compares the divided voltage value with the reference value VR. When the divided voltage value is different from the reference value VR, the voltage value at the first terminal of the voltage regulator 2412 will change, thereby affecting the light-emitting result of the light-emitting diode. Therefore, the feedback signal SFB generated by the coupling transistor will also change. For example, when the voltage value of the output voltage VO increases, the divided voltage value received by the voltage regulator 2412 will increase. Therefore, the voltage value of the first terminal of the voltage regulator 2412 will be correspondingly reduced. The brightness of the light-emitting diode will increase. Therefore, the current value of the feedback signal SFB provided by the coupling transistor will increase. Then the charging result of the capacitor CB in the image feedback and compensation circuit 240. The controller 130 will reduce the duty cycle of the switching control signal GD according to the charging result of the capacitor CB. Therefore, the voltage value of the output voltage VO will be reduced. Similarly, when the voltage value of the output voltage VO decreases, the controller 130 increases the duty cycle of the switching control signal GD. Therefore, the voltage value of the output voltage VO will be increased. Therefore, in the power supply state, the voltage value of the output voltage VO can be stabilized.

在本實施例中，第一補償電路2413耦接於穩壓器2412的第一端與穩壓器2412的參考端之間。在本實施例中，第一補償電路2413與電阻器R1決定出第一極點。此外，第一補償電路2413獨自決定出第二極點以及第一零點。應注意的是，在供電狀態中，第一補償電路2413增加了頻寬以及相位裕度（phase margin）。In this embodiment, the first compensation circuit 2413 is coupled between the first terminal of the voltage regulator 2412 and the reference terminal of the voltage regulator 2412 . In this embodiment, the first compensation circuit 2413 and the resistor R1 determine the first pole. In addition, the first compensation circuit 2413 independently determines the second pole and the first zero point. It should be noted that in the power supply state, the first compensation circuit 2413 increases the bandwidth and phase margin.

在本實施例中，判斷電路242會對感測電壓值VS進行判斷。當感測電壓值VS大於或等於參考值VR時，判斷電路242會獲知電源供應裝置200處於供電狀態。因此，在供電狀態中，判斷電路242並不會建立第二補償電路。在另一方面，當感測電壓值VS小於參考值VR時，判斷電路242會獲知電源供應裝置200處於低負載狀態。因此，判斷電路242會建立第二補償電路。In this embodiment, the determination circuit 242 determines the sensing voltage value VS. When the sensing voltage value VS is greater than or equal to the reference value VR, the determination circuit 242 will know that the power supply device 200 is in the power supply state. Therefore, in the power supply state, the judgment circuit 242 does not establish the second compensation circuit. On the other hand, when the sensed voltage value VS is less than the reference value VR, the determination circuit 242 will know that the power supply device 200 is in a low load state. Therefore, the judgment circuit 242 establishes the second compensation circuit.

應注意的是，第二補償電路與電阻器R1決定出第二零點。第二補償電路獨自決定出第三極點。因此，在低負載狀態中，第一補償電路2413與第二補償電路共同提供了3個極點以及2零點。第一補償電路2413與第二補償電路進一步增加了頻寬。此外，第一補償電路2413與第二補償電路還能夠降低回路增益。It should be noted that the second compensation circuit and resistor R1 determine the second zero point. The second compensation circuit alone determines the third pole. Therefore, in the low load state, the first compensation circuit 2413 and the second compensation circuit jointly provide 3 poles and 2 zeros. The first compensation circuit 2413 and the second compensation circuit further increase the bandwidth. In addition, the first compensation circuit 2413 and the second compensation circuit can also reduce the loop gain.

請同時參考圖2、圖3、圖4以及圖5，圖3是依據本發明一實施例所繪示的切換控制訊號以及輸出電壓的波形圖。圖4是依據本發明一實施例所繪示的供電狀態的回路增益示意圖。圖5是依據本發明一實施例所繪示的低負載狀態的回路增益示意圖。在本實施例中，第一補償電路2413包括電容器C1、C2以及電阻器R2。電容器C1耦接於穩壓器2412的第一端與穩壓器2412的參考端之間。電容器C2與電阻器R2串聯耦接於穩壓器2412的第一端與穩壓器2412的參考端之間。基於公式(1)、公式(2)以及公式(3)，電容器C1的電容值與電阻器R1的電阻值決定出第一極點f0。電容器C2的電容值與電阻器R2的電阻值決定出第一零點f1。電容器C1的電容值與電阻器R2的電阻值決定出第二極點f2。Please refer to FIG. 2 , FIG. 3 , FIG. 4 and FIG. 5 at the same time. FIG. 3 is a waveform diagram of a switching control signal and an output voltage according to an embodiment of the present invention. FIG. 4 is a schematic diagram of a loop gain in a power supply state according to an embodiment of the present invention. FIG. 5 is a schematic diagram of the loop gain in a low load state according to an embodiment of the present invention. In this embodiment, the first compensation circuit 2413 includes capacitors C1 and C2 and a resistor R2. The capacitor C1 is coupled between the first terminal of the voltage regulator 2412 and the reference terminal of the voltage regulator 2412 . The capacitor C2 and the resistor R2 are coupled in series between the first terminal of the voltage regulator 2412 and the reference terminal of the voltage regulator 2412 . Based on formula (1), formula (2) and formula (3), the capacitance value of capacitor C1 and the resistance value of resistor R1 determine the first pole f0. The capacitance value of capacitor C2 and the resistance value of resistor R2 determine the first zero point f1. The capacitance value of capacitor C1 and the resistance value of resistor R2 determine the second pole f2.

………….……公式(1) ………….……Formula 1)

………….……公式(2) ………….……Formula (2)

………….……公式(3) ………….……Formula (3)

rR1是電阻器R1的電阻值。rR2是電阻器R2的電阻值。cC1是電容器C1的電容值。cC2是電容器C2的電容值。在本實施例中，第一零點f1的頻率被設計以大於第一極點f0的頻率。第二極點f2的頻率被設計以大於第一零點f1的頻率。rR1 is the resistance value of resistor R1. rR2 is the resistance value of resistor R2. cC1 is the capacitance value of capacitor C1. cC2 is the capacitance value of capacitor C2. In this embodiment, the frequency of the first zero point f1 is designed to be greater than the frequency of the first pole f0. The frequency of the second pole f2 is designed to be greater than the frequency of the first zero point f1.

判斷電路242包括比較器CP、開關Q2、Q3、輔助電阻器R3以及輔助電容器C3。比較器CP的非反相輸入端耦接於穩壓器2412的參考端。比較器CP的非反相輸入端接收感測電壓值VS。開關Q2的第一端耦接於次級側電路120的輸出端。開關Q2的控制端耦接於比較器CP的輸出端。輔助電阻器R3耦接於穩壓器2412的參考端與開關Q2的第二端之間。開關Q3的第一端耦接於次級側電路120的輸出端。開關Q3的控制端耦接於比較器CP的輸出端。輔助電容器C3耦接於穩壓器2412的參考端與開關Q3的第二端之間。The judgment circuit 242 includes a comparator CP, switches Q2, Q3, an auxiliary resistor R3, and an auxiliary capacitor C3. The non-inverting input terminal of the comparator CP is coupled to the reference terminal of the voltage regulator 2412 . The non-inverting input terminal of the comparator CP receives the sensed voltage value VS. The first terminal of the switch Q2 is coupled to the output terminal of the secondary side circuit 120 . The control terminal of the switch Q2 is coupled to the output terminal of the comparator CP. The auxiliary resistor R3 is coupled between the reference terminal of the voltage regulator 2412 and the second terminal of the switch Q2. The first terminal of the switch Q3 is coupled to the output terminal of the secondary side circuit 120 . The control terminal of switch Q3 is coupled to the output terminal of comparator CP. The auxiliary capacitor C3 is coupled between the reference terminal of the voltage regulator 2412 and the second terminal of the switch Q3.

在本實施例中，在供電狀態ST1，控制器130會提供具有一操作頻率範圍的切換控制訊號GD。為了穩定輸出電壓VO的電壓值，切換控制訊號GD的切換頻率被調整於操作頻率範圍中。在供電狀態ST1，輸出電流值IO會較高。因此，感測電壓值VS會大於或等於參考值VR。當感測電壓值VS大於或等於參考值VR時，比較器CP會提供低電壓訊號以斷開開關Q2、Q3。因此，回授與補償電路240會提供回路增益LG1。輸出電壓VO的電壓值會基於回路增益LG1的增益值AV1被增益。增益值AV1大致上等於電阻器R2的電阻值除以電阻器R1的電阻值所獲得的第一商。In this embodiment, in the power supply state ST1, the controller 130 provides a switching control signal GD having an operating frequency range. In order to stabilize the voltage value of the output voltage VO, the switching frequency of the switching control signal GD is adjusted within the operating frequency range. In the power supply state ST1, the output current value IO will be higher. Therefore, the sensing voltage value VS will be greater than or equal to the reference value VR. When the sensed voltage value VS is greater than or equal to the reference value VR, the comparator CP provides a low voltage signal to turn off the switches Q2 and Q3. Therefore, the feedback and compensation circuit 240 provides the loop gain LG1. The voltage value of the output voltage VO will be gained based on the gain value AV1 of the loop gain LG1. The gain value AV1 is substantially equal to the first quotient obtained by dividing the resistance value of the resistor R2 by the resistance value of the resistor R1.

在低負載狀態ST2中，輸出電流值IO會下降。因此，感測電壓值VS會小於參考值VR。當感測電壓值VS小於參考值VR時，比較器CP會提供高電壓訊號以使控制器130對初級側電路110進行降頻操作。因此，切換控制訊號GD的切換頻率會被降低。在低負載狀態ST2中，切換控制訊號GD的切換頻率會低於操作頻率範圍中的最低頻率。In the low load state ST2, the output current value IO will decrease. Therefore, the sensing voltage value VS will be smaller than the reference value VR. When the sensed voltage value VS is less than the reference value VR, the comparator CP provides a high voltage signal so that the controller 130 performs a frequency reduction operation on the primary side circuit 110 . Therefore, the switching frequency of the switching control signal GD will be reduced. In the low load state ST2, the switching frequency of the switching control signal GD will be lower than the lowest frequency in the operating frequency range.

此外，比較器CP還利用高電壓訊號以導通開關Q2、Q3。因此，比較器CP使輔助電阻器R3與輔助電容器C3被建立為第二補償電路。In addition, the comparator CP also uses the high voltage signal to turn on the switches Q2 and Q3. Therefore, the comparator CP causes the auxiliary resistor R3 and the auxiliary capacitor C3 to be established as the second compensation circuit.

基於公式(4)以及公式(5)，輔助電容器C3的電容值與第一電阻器R1的電阻值決定第二零點f3。輔助電阻器R3的電阻值與輔助電容器C3的電容值決定第三極點f4。Based on formula (4) and formula (5), the capacitance value of the auxiliary capacitor C3 and the resistance value of the first resistor R1 determine the second zero point f3. The resistance value of the auxiliary resistor R3 and the capacitance value of the auxiliary capacitor C3 determine the third pole f4.

………….……公式(4) ………….……Formula (4)

………….……公式(5) ………….……Formula (5)

cC3是輔助電容器C3的電容值。rR3是輔助電阻器R3的電阻值。在本實施例中，第二零點f3的頻率被設計以大於第二極點f2的頻率。第三極點f4的頻率被設計以大於第二零點f3的頻率。因此，在低負載狀態ST2中，回授與補償電路240會提供回路增益LG2。回路增益LG2的增益值AV2低於增益值AV1。因此，輸出電壓VO的電壓值會基於回路增益LG2的增益值AV2被降低。在本實施例中，增益值AV2大致上等於輔助電容器C3的電容值除以電容器C2的電容值所獲得的第二商。cC3 is the capacitance value of auxiliary capacitor C3. rR3 is the resistance value of auxiliary resistor R3. In this embodiment, the frequency of the second zero point f3 is designed to be greater than the frequency of the second pole f2. The frequency of the third pole f4 is designed to be greater than the frequency of the second zero point f3. Therefore, in the low load state ST2, the feedback and compensation circuit 240 provides the loop gain LG2. The gain value AV2 of the loop gain LG2 is lower than the gain value AV1. Therefore, the voltage value of the output voltage VO will be reduced based on the gain value AV2 of the loop gain LG2. In this embodiment, the gain value AV2 is substantially equal to the second quotient obtained by dividing the capacitance value of the auxiliary capacitor C3 by the capacitance value of the capacitor C2.

舉例來說，電源供應裝置200應用於筆記型電腦，在供電狀態ST1，輸出電壓VO的電壓值約為19伏特。輸出電流值IO約為4.74安培。在低負載狀態ST2中，輸出電流值IO低於1安培，使得關聯於輸出電流值IO的感測電壓值VS小於參考值VR。控制器130對初級側電路110進行降頻操作。因此，初級側電路110的切換功耗能夠被下降。此外，第二補償電路被建立以降低回路增益。輸出電壓VO的電壓值被降低10伏特。因此，電源供應裝置200的輸出功率能夠大幅被下降。當電源供應裝置200回到供電狀態ST1時，感測電壓值VS會大於或等於參考值VR。因此，控制器130停止對初級側電路110進行降頻操作。此外，第二補償電路不會被建立。輸出電壓VO的電壓值則會回到19伏特。For example, the power supply device 200 is applied to a notebook computer, and in the power supply state ST1, the voltage value of the output voltage VO is approximately 19 volts. The output current value IO is approximately 4.74 amps. In the low load state ST2, the output current value IO is lower than 1 amp, so that the sensing voltage value VS associated with the output current value IO is smaller than the reference value VR. The controller 130 performs a frequency down operation on the primary side circuit 110 . Therefore, the switching power consumption of the primary side circuit 110 can be reduced. Additionally, a second compensation circuit is built to reduce the loop gain. The voltage value of the output voltage VO is reduced by 10 volts. Therefore, the output power of the power supply device 200 can be greatly reduced. When the power supply device 200 returns to the power supply state ST1, the sensing voltage value VS will be greater than or equal to the reference value VR. Therefore, the controller 130 stops the frequency down operation of the primary side circuit 110 . Furthermore, the second compensation circuit will not be established. The voltage value of the output voltage VO will return to 19 volts.

綜上所述，當感測電壓值小於參考值時，電源供應裝置的回路增益被降低，輸出電壓的電壓值被降低。因此，輸出功率能夠被大幅下降。如此一來，在低負載條件下，電源供應裝置能夠符合滿足現行規範的節能要求。In summary, when the sensed voltage value is less than the reference value, the loop gain of the power supply device is reduced and the voltage value of the output voltage is reduced. Therefore, the output power can be significantly reduced. In this way, under low load conditions, the power supply device can meet the energy saving requirements of current regulations.

雖然本發明已以實施例揭露如上，然其並非用以限定本發明，任何所屬技術領域中具有通常知識者，在不脫離本發明的精神和範圍內，當可作些許的更動與潤飾，故本發明的保護範圍當視後附的申請專利範圍所界定者為準。Although the present invention has been disclosed above through embodiments, they are not intended to limit the present invention. Anyone with ordinary knowledge in the technical field may make some modifications and modifications without departing from the spirit and scope of the present invention. Therefore, The protection scope of the present invention shall be determined by the appended patent application scope.

100、200:電源供應裝置100, 200: Power supply device

110:初級側電路110: Primary side circuit

120:次級側電路120:Secondary side circuit

130:控制器130:Controller

140、240:回授與補償電路140, 240: Feedback and compensation circuit

241:回授電路241:Feedback circuit

2411:耦合電路2411: Coupling circuit

2412:穩壓器2412: Voltage regulator

2413:第一補償電路2413: First compensation circuit

242:判斷電路242:Judgement circuit

AV1、AV2:增益值AV1, AV2: gain value

C1、C2、CB:電容器C1, C2, CB: capacitor

CO:輸出電容器CO: output capacitor

C3:輔助電容器C3: Auxiliary capacitor

CP:比較器CP: Comparator

CR:電源轉換器CR: power converter

DO:輸出二極體DO: output diode

f0:第一極點f0: first pole

f1:第一零點f1: first zero point

f2:第二極點f2: second pole

f3:第二零點f3: second zero point

f4:第三極點f4: third pole

GD:切換控制訊號GD: switching control signal

GND1、GND2:接地端GND1, GND2: ground terminal

IO:輸出電流值IO: output current value

LG、LG1、LG2:回路增益LG, LG1, LG2: loop gain

LM:激磁電感器LM: Magnetizing inductor

NP:初級側繞組NP: primary side winding

NS:次級側繞組NS: secondary side winding

Q1:功率開關Q1: Power switch

Q2、Q3:開關Q2, Q3: switch

R1、R2:電阻器R1, R2: resistor

R3:輔助電阻器R3: Auxiliary resistor

RB:分壓電阻器RB: voltage dividing resistor

RS:感測電阻器RS: sensing resistor

SFB:回授訊號SFB: feedback signal

ST1:供電狀態ST1: power supply status

ST2:低負載狀態ST2: low load state

t:時間t: time

TR:變壓器TR: Transformer

VI:輸入電壓VI: input voltage

VO:輸出電壓VO: output voltage

VS:感測電壓值VS: sensing voltage value

VR:參考值VR: reference value

圖1是依據本發明第一實施例所繪示的電源供應裝置的示意圖。圖2是依據本發明第二實施例所繪示的電源供應裝置的示意圖。圖3是依據本發明一實施例所繪示的切換控制訊號以及輸出電壓的波形圖。圖4是依據本發明一實施例所繪示的供電狀態的回路增益示意圖。圖5是依據本發明一實施例所繪示的低負載狀態的回路增益示意圖。 FIG. 1 is a schematic diagram of a power supply device according to a first embodiment of the present invention. FIG. 2 is a schematic diagram of a power supply device according to a second embodiment of the present invention. FIG. 3 is a waveform diagram of a switching control signal and an output voltage according to an embodiment of the present invention. FIG. 4 is a schematic diagram of a loop gain in a power supply state according to an embodiment of the present invention. FIG. 5 is a schematic diagram of the loop gain in a low load state according to an embodiment of the present invention.

100:電源供應裝置 100:Power supply device

110:初級側電路 110: Primary side circuit

120:次級側電路 120:Secondary side circuit

130:控制器 130:Controller

140:回授與補償電路 140: Feedback and compensation circuit

CO:輸出電容器 CO: output capacitor

CR:電源轉換器 CR: power converter

DO:輸出二極體 DO: output diode

GD:切換控制訊號 GD: switching control signal

GND1、GND2:接地端 GND1, GND2: ground terminal

IO:輸出電流值 IO: output current value

LG:回路增益 LG: loop gain

LM:激磁電感器 LM: Magnetizing inductor

NP:初級側繞組 NP: primary side winding

NS:次級側繞組 NS: secondary side winding

Q1:功率開關 Q1: Power switch

RS:感測電阻器 RS: sensing resistor

TR:變壓器 TR: Transformer

VI:輸入電壓 VI: input voltage

VO:輸出電壓 VO: output voltage

VS:感測電壓值 VS: sensing voltage value

VR:參考值 VR: reference value

Claims

一種電源供應裝置，包括：一電源轉換器，包括一初級側電路以及一次級側電路，其中該次級側電路依據一輸出電流值產生一感測電壓值；一控制器，耦接於該初級側電路，經配置以利用一控制訊號來控制該初級側電路；以及一回授與補償電路，耦接於該次級側電路以及該控制器，經配置以：在該回授與補償電路中提供一回路增益，其中當該感測電壓值大於或等於一參考值時，該回授與補償電路使該控制器來控制該初級側電路，從而使該次級側電路輸出一輸出電壓，其中該輸出電壓關聯於該回路增益，並且其中當該感測電壓值小於該參考值時：該回授與補償電路使該控制器對該初級側電路進行一降頻操作，並且該回授與補償電路增加該回路增益的零點與極點以降低該回路增益的增益值，從而使該輸出電壓的電壓值依據該回路增益被降低。 A power supply device includes: a power converter, including a primary side circuit and a primary side circuit, wherein the secondary side circuit generates a sensing voltage value based on an output current value; a controller coupled to the primary side circuit a side circuit configured to utilize a control signal to control the primary side circuit; and a feedback and compensation circuit coupled to the secondary side circuit and the controller configured to: in the feedback and compensation circuit Provide a loop gain, wherein when the sensed voltage value is greater than or equal to a reference value, the feedback and compensation circuit enables the controller to control the primary side circuit, thereby causing the secondary side circuit to output an output voltage, wherein The output voltage is related to the loop gain, and when the sensed voltage value is less than the reference value: the feedback and compensation circuit causes the controller to perform a frequency reduction operation on the primary side circuit, and the feedback and compensation circuit The circuit increases the zeros and poles of the loop gain to reduce the gain value of the loop gain, so that the voltage value of the output voltage is reduced according to the loop gain.

如請求項1所述的電源供應裝置，其中該回授與補償電路包括：一判斷電路，經配置以對該感測電壓值與該參考值進行比較，當該感測電壓值小於該參考值時，降低該回路增益，並指示該控制器對該初級側電路進行該降頻操作。 The power supply device of claim 1, wherein the feedback and compensation circuit includes: a judgment circuit configured to compare the sensed voltage value with the reference value. When the sensed voltage value is less than the reference value When , reduce the loop gain and indicate The controller performs the frequency reduction operation on the primary side circuit.

如請求項2所述的電源供應裝置，其中該回授與補償電路還包括：一回授電路，經配置以在一供電狀態中依據該輸出電壓的電壓值來提供一回授訊號，其中該控制器依據該回授訊號調節該控制訊號的頻率以穩定該輸出電壓的電壓值。 The power supply device of claim 2, wherein the feedback and compensation circuit further includes: a feedback circuit configured to provide a feedback signal according to the voltage value of the output voltage in a power supply state, wherein the The controller adjusts the frequency of the control signal according to the feedback signal to stabilize the voltage value of the output voltage.

如請求項3所述的電源供應裝置，其中該回授電路包括：一耦合電路，耦接於該控制器與該次級側電路之間；一穩壓器，該穩壓器的第一端耦接於該耦合電路，該穩壓器的第二端耦接於該次級側電路的參考低電壓，該穩壓器的參考端用以提供該參考值，其中該穩壓器依據該輸出電壓的變化使該耦合電路提供該回授訊號；一第一電阻器，耦接於該次級側電路的輸出端與該穩壓器的參考端之間；一分壓電阻器，耦接於該穩壓器的參考端與該穩壓器的第二端之間；以及一第一補償電路，耦接於該穩壓器的第一端與該穩壓器的參考端之間，該第一補償電路與該第一電阻器決定該回路增益的一第一極點，並且該第一補償電路獨自決定該回路增益的一第二極點以及該回路增益的一第一零點。 The power supply device of claim 3, wherein the feedback circuit includes: a coupling circuit coupled between the controller and the secondary side circuit; a voltage regulator, the first terminal of the voltage regulator Coupled to the coupling circuit, the second terminal of the voltage regulator is coupled to the reference low voltage of the secondary side circuit, and the reference terminal of the voltage regulator is used to provide the reference value, wherein the voltage regulator is based on the output The change in voltage causes the coupling circuit to provide the feedback signal; a first resistor is coupled between the output terminal of the secondary side circuit and the reference terminal of the voltage regulator; a voltage dividing resistor is coupled to between the reference terminal of the voltage regulator and the second terminal of the voltage regulator; and a first compensation circuit coupled between the first terminal of the voltage regulator and the reference terminal of the voltage regulator, the third a compensation circuit and the first resistor determine a first pole of the loop gain, and The first compensation circuit alone determines a second pole of the loop gain and a first zero point of the loop gain.

如請求項4所述的電源供應裝置，其中該第一補償電路包括：一第一電容器，耦接於該穩壓器的第一端與該穩壓器的參考端之間；一第二電阻器；以及一第二電容器，與該第二電阻器串聯耦接於該穩壓器的第一端與該穩壓器的參考端之間。 The power supply device of claim 4, wherein the first compensation circuit includes: a first capacitor coupled between the first terminal of the voltage regulator and the reference terminal of the voltage regulator; a second resistor and a second capacitor coupled in series with the second resistor between the first terminal of the voltage regulator and the reference terminal of the voltage regulator.

如請求項5所述的電源供應裝置，其中：該第一電容器的電容值與該第一電阻器的電阻值決定該第一極點，該第一電容器的電容值與該第二電阻器的電阻值決定該第二極點，並且該第二電容器的電容值與該第二電阻器的電阻值決定該第一零點。 The power supply device of claim 5, wherein: the capacitance value of the first capacitor and the resistance value of the first resistor determine the first pole, and the capacitance value of the first capacitor and the resistance value of the second resistor determine the first pole. The capacitance value of the second capacitor and the resistance value of the second resistor determine the first zero point.

如請求項4所述的電源供應裝置，其中：當該感測電壓值小於該參考值時，該判斷電路建立一第二補償電路，該第二補償電路與該第一電阻器決定該回路增益的一第二零點，並且該第二補償電路獨自決定該回路增益的一第三極點。 The power supply device of claim 4, wherein: when the sensed voltage value is less than the reference value, the judgment circuit establishes a second compensation circuit, and the second compensation circuit and the first resistor determine the loop gain. a second zero point, and the second compensation circuit alone determines a third pole of the loop gain.

如請求項7所述的電源供應裝置，其中該判斷電路包括：一比較器，該比較器的非反相輸入端耦接於該穩壓器的參考端，該比較器的非反相輸入端接收該感測電壓值；一第一開關，該第一開關的第一端耦接於該次級側電路的輸出端，該第一開關的控制端耦接於該比較器的輸出端；一輔助電阻器，耦接於該穩壓器的參考端與該第一開關的第二端之間；一第二開關，該第二開關的第一端耦接於該次級側電路的輸出端，該第二開關的控制端耦接於該比較器的輸出端；以及一輔助電容器，耦接於該穩壓器的參考端與該第二開關的第二端之間。 The power supply device of claim 7, wherein the judgment circuit includes: a comparator, the non-inverting input terminal of the comparator is coupled to the reference terminal of the voltage regulator, the non-inverting input terminal of the comparator Receive the sensed voltage value; a first switch, the first terminal of the first switch is coupled to the output terminal of the secondary side circuit, and the control terminal of the first switch is coupled to the output terminal of the comparator; a An auxiliary resistor, coupled between the reference terminal of the voltage regulator and the second terminal of the first switch; a second switch, the first terminal of the second switch is coupled to the output terminal of the secondary side circuit , the control terminal of the second switch is coupled to the output terminal of the comparator; and an auxiliary capacitor is coupled between the reference terminal of the voltage regulator and the second terminal of the second switch.

如請求項8所述的電源供應裝置，其中當該感測電壓值小於該參考值時，該比較器導通該第一開關以及該第二開關，使該輔助電阻器與該輔助電容器被建立為該第二補償電路。 The power supply device of claim 8, wherein when the sensed voltage value is less than the reference value, the comparator turns on the first switch and the second switch, so that the auxiliary resistor and the auxiliary capacitor are established as the second compensation circuit.

如請求項8所述的電源供應裝置，其中：該輔助電容器的電容值與該第一電阻器的電阻值決定該第二零點，並且該輔助電阻器的電阻值與該輔助電容器的電容值決定該第三極點。 The power supply device of claim 8, wherein: the capacitance value of the auxiliary capacitor and the resistance value of the first resistor determine the second zero point, and the resistance value of the auxiliary resistor and the capacitance value of the auxiliary capacitor Determine this third pole.