TWI825945B - Power supply device with high conversion efficiency - Google Patents

Abstract

A power supply device includes a bridge rectifier, a boost inductor, a first power switch element, a PWM (Pulse Width Modulation) IC (Integrated Circuit), a first output stage circuit, a feedback compensation circuit, a transformer, a second power switch element, a second output stage circuit, a third output stage circuit, and an MCU (Microcontroller Unit). The transformer includes a main coil, a secondary coil, and an auxiliary coil. The third output stage circuit is coupled to the auxiliary coil, and is configured to generate a supply voltage. The MCU detects a sense voltage from the second power switch element. The MCU selectively enables or disables the feedback compensation circuit according to the supply voltage and the sense voltage.

Description

High conversion efficiency power supply

The present invention relates to a power supply, and in particular to a power supply with high conversion efficiency.

The power supply is an indispensable component in the notebook computer field. However, if the conversion efficiency of the power supply is insufficient, it will easily cause the overall operating performance of the related notebook computer to decline. In view of this, it is necessary to propose a new solution to overcome the difficulties faced by previous technologies.

In a preferred embodiment, the present invention proposes a power supply with high conversion efficiency, including: a bridge rectifier to generate a rectified potential according to a first input potential and a second input potential; a boost inductor to receive the rectifying potential; a first power switch to selectively couple the boost inductor to a ground potential according to a first clock potential; a pulse width modulation integrated circuit according to a feedback potential to generate the first clock potential; a first output stage circuit coupled to the boost inductor and generating an intermediate potential; a feedback compensation circuit to generate the feedback potential according to the intermediate potential; a transformer , including a main coil, a auxiliary coil, and an auxiliary coil, wherein the main coil is used to receive the intermediate potential; a second power switch selectively couples the main coil according to a second clock potential connected to the ground potential; a second output stage circuit coupled to the auxiliary coil and generating an output potential; a third output stage circuit coupled to the auxiliary coil and generating a supply potential; and a microcontroller The microcontroller generates the second clock potential and detects a sensing potential from the second power switch, wherein the microcontroller further selectively enables or disables the power according to the supply potential and the sensing potential. The feedback compensation circuit.

In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are listed below and described in detail with reference to the accompanying drawings.

Certain words are used in the specification and patent claims to refer to specific components. Those skilled in the art will understand that hardware manufacturers may use different names to refer to the same component. This specification and the patent application do not use differences in names as a way to distinguish components, but differences in functions of components as a criterion for distinction. The words "include" and "include" mentioned throughout the specification and the scope of the patent application are open-ended terms, and therefore should be interpreted as "include but not limited to." The term "approximately" means that within an acceptable error range, those skilled in the art can solve the technical problem and achieve the basic technical effect within a certain error range. In addition, the word "coupling" in this specification includes any direct and indirect electrical connection means. Therefore, if a first device is coupled to a second device, it means that the first device can be directly electrically connected to the second device, or indirectly electrically connected to the second device via other devices or connections. Two devices.

Figure 1 is a schematic diagram of a power supply 100 according to an embodiment of the present invention. For example, the power supply 100 can be applied to a desktop computer, a notebook computer, or an all-in-one computer. As shown in Figure 1, the power supply 100 includes: a bridge rectifier 110, a boost inductor LU, a first power switch 120, and a pulse width modulation integrated circuit (PWM). IC) 130, a first output stage circuit 140, a feedback compensation circuit 150, a transformer 160, a second power switch 170, a second output stage circuit 180, a third output stage circuit 190, and a micro Controller (Microcontroller Unit, MCU)195. It should be noted that, although not shown in FIG. 1 , the power supply 100 may further include other components, such as a voltage regulator or/and a negative feedback circuit.

The bridge rectifier 110 can generate a rectified potential VR according to a first input potential VIN1 and a second input potential VIN2, wherein one of the first input potential VIN1 and the second input potential VIN2 can have any frequency and any amplitude. AC voltage. For example, the frequency of the AC voltage can be about 50Hz or 60Hz, and the root mean square (RMS) of the AC voltage can be about 90V to 264V, but it is not limited thereto. The boost inductor LU receives the rectified potential VR. The first power switch 120 can selectively couple the boost inductor LU to a ground potential VSS (eg, 0V) according to a first clock potential VA1. For example, if the first clock potential VA1 is a high logic level (ie, logic “1”), the first power switch 120 may couple the boost inductor LU to the ground potential VSS (ie, the logic level VSS). A power switch 120 can be approximated as a short-circuit path); conversely, if the first clock potential VA1 is a low logic level (ie, logic "0"), the first power switch 120 will not boost the voltage The inductor LU is coupled to the ground potential VSS (ie, the first power switch 120 may approximate an open path). The pulse width modulation integrated circuit 130 can generate the first clock potential VA1 according to a feedback potential VF. The first output stage circuit 140 is coupled to the boost inductor LU and can generate an intermediate potential VE. In some embodiments, the bridge rectifier 110 , the boost inductor LU, the first power switch 120 , and the first output stage circuit 140 may together form a power factor corrector (Power Factor Corrector) of the power supply 100 .

The feedback compensation circuit 150 can generate the feedback potential VF according to the intermediate potential VE. The transformer 160 includes a primary coil 161, a secondary coil 162, and an auxiliary coil 163. The primary coil 161 and the auxiliary coil 163 can be located on the same side of the transformer 160, and the secondary coil 162 can be located on the opposite side of the transformer 160. . The main coil 161 can receive the intermediate potential VE, and the secondary coil 162 and the auxiliary coil 163 can operate in response to the intermediate potential VE. The second power switch 170 can selectively couple the main coil 161 to the ground potential VSS according to a second clock potential VA2. For example, if the second clock potential VA2 is a high logic level, the second power switch 170 can couple the main coil 161 to the ground potential VSS (that is, the second power switch 170 can be approximately a short-circuit path ); On the contrary, if the second clock potential VA2 is a low logic level, the second power switch 170 will not couple the main coil 161 to the ground potential VSS (that is, the second power switch 170 can be approximately an open path). The second output stage circuit 180 is coupled to the secondary coil 162 and can generate an output potential VOUT. For example, the output potential VOUT may be a DC potential, and its potential level may be between 18V and 22V, but is not limited thereto. The third output stage circuit 190 is coupled to the auxiliary coil 163 and can generate a supply potential VP.

The microcontroller 195 can be powered by the supply potential VP. The microcontroller 195 can generate the second clock potential VA2 and detect a sensing potential VS from the second power switch 170 . In addition, the microcontroller 195 can selectively enable or disable the feedback compensation circuit 150 according to the supply potential VP and the sensing potential VS. For example, the microcontroller 195 can output a notification potential VN to the pulse width modulation integrated circuit 130 to indirectly control the feedback compensation circuit 150 . When the feedback compensation circuit 150 is enabled, the power factor corrector of the power supply 100 will be enabled; conversely, when the feedback compensation circuit 150 is disabled, the power factor corrector of the power supply 100 will be enabled. will be closed together. Under this design, the power supply 100 can automatically adjust its internal circuit according to the real-time output conditions, thereby greatly increasing its own conversion efficiency.

The following embodiments will introduce the detailed structure and operation of the power supply 100 . It must be understood that these drawings and descriptions are only examples and are not intended to limit the scope of the invention.

Figure 2 is a circuit diagram of a power supply 200 according to an embodiment of the present invention. In the embodiment of FIG. 2, the power supply 200 has a first input node NIN1, a second input node NIN2, and an output node NOUT, and includes a bridge rectifier 210, a boost inductor LU, a first A power switch 220, a pulse width modulation integrated circuit 230, a first output stage circuit 240, a feedback compensation circuit 250, a transformer 260, a second power switch 270, and a second output stage circuit 280, a third output stage circuit 290, and a microcontroller 295. The first input node NIN1 and the second input node NIN2 of the power supply 200 can be used to receive a first input potential VIN1 and a second input potential VIN2. The output node NOUT of the power supply 200 can be used to output an output potential VOUT.

The bridge rectifier 210 includes a first diode D1, a second diode D2, a third diode D3, and a fourth diode D4. The first diode D1 has an anode and a cathode, wherein the anode of the first diode D1 is coupled to the first input node NIN1, and the cathode of the first diode D1 is coupled to a first node N1 To output the rectified potential VR. The second diode D2 has an anode and a cathode, wherein the anode of the second diode D2 is coupled to the second input node NIN2, and the cathode of the second diode D2 is coupled to the first node N1. The third diode D3 has an anode and a cathode, wherein the anode of the third diode D3 is coupled to a ground potential VSS, and the cathode of the third diode D3 is coupled to the first input node NIN1. The fourth diode D4 has an anode and a cathode, wherein the anode of the fourth diode D4 is coupled to the ground potential VSS, and the cathode of the fourth diode D4 is coupled to the second input node NIN2.

The boost inductor LU has a first terminal and a second terminal, wherein the first terminal of the boost inductor LU is coupled to the first node N1 to receive the rectified potential VR, and the second terminal of the boost inductor LU is coupled to a second node N2.

The first power switch 220 includes a first transistor M1. For example, the first transistor M1 may be an N-type Metal-Oxide-Semiconductor Field-Effect Transistor (NMOSFET). The first transistor M1 has a control terminal (for example: a gate), a first terminal (for example: a source), and a second terminal (for example: a drain), wherein the control terminal of the first transistor M1 The terminal is used to receive a first clock potential VA1, the first terminal of the first transistor M1 is coupled to the ground potential VSS, and the second terminal of the first transistor M1 is coupled to the second node N2.

The pulse width modulation integrated circuit 230 can generate the first clock potential VA1 according to a feedback potential VF. For example, the first clock potential VA1 can be maintained at a fixed potential when the power supply 200 is first initialized, and can provide a periodic clock waveform after the power supply 200 enters the normal use stage.

The first output stage circuit 240 includes a fifth diode D5 and a first capacitor C1. The fifth diode D5 has an anode and a cathode, wherein the anode of the fifth diode D5 is coupled to the second node N2, and the cathode of the fifth diode D5 is coupled to a third node N3. Output an intermediate potential VE. The first capacitor C1 has a first terminal and a second terminal, wherein the first terminal of the first capacitor C1 is coupled to the third node N3, and the second terminal of the first capacitor C1 is coupled to the ground potential VSS.

In some embodiments, the bridge rectifier 210 , the boost inductor LU, the first power switch 220 , and the first output stage circuit 240 may together form a power factor corrector of the power supply 200 . In addition, the feedback compensation circuit 250 can generate the feedback potential VF according to the intermediate potential VE, and its circuit structure will be described in detail in subsequent embodiments.

The transformer 260 includes a primary coil 261, a secondary coil 262, and an auxiliary coil 263. The transformer 260 may further have a built-in magnetizing inductor LM. The magnetizing inductor LM may be an inherent component produced when the transformer 260 is manufactured, and is not an external independent component. The main coil 261, the auxiliary coil 263, and the exciting inductor LM can all be located on the same side of the transformer 260 (for example, the primary side), while the secondary coil 262 can be located on the opposite side of the transformer 260 (for example, the secondary side). can be isolated from the primary side). In detail, the main coil 261 has a first end and a second end, wherein the first end of the main coil 261 is coupled to the third node N3 to receive the intermediate potential VE, and the second end of the main coil 261 is coupled to Connected to a fourth node N4. The exciting inductor LM has a first end and a second end, wherein the first end of the exciting inductor LM is coupled to the third node N3, and the second end of the exciting inductor LM is coupled to the fourth node N4. . The secondary coil 262 has a first end and a second end, wherein the first end of the secondary coil 262 is coupled to a fifth node N5, and the second end of the secondary coil 262 is coupled to a common node NCM. For example, the common node NCM can be regarded as another ground potential, which can be the same as or different from the aforementioned ground potential VSS. The auxiliary coil 263 has a first end and a second end, wherein the first end of the auxiliary coil 263 is coupled to a sixth node N6, and the second end of the auxiliary coil 263 is coupled to the ground potential VSS.

The second power switch 270 includes a second transistor M2 and a sensing resistor RS. For example, the second transistor M2 may be an N-type MOSFET. The second transistor M2 has a control terminal (for example, a gate), a first terminal (for example, a source), and a second terminal (for example, a drain), wherein the control terminal of the second transistor M2 The terminal is used to receive a second clock potential VA2. The first terminal of the second transistor M2 is coupled to a sensing node NS, and the second terminal of the second transistor M2 is coupled to the fourth node N4. . The sensing resistor RS has a very small resistance value, which is almost negligible. The sensing resistor RS has a first end and a second end, wherein the first end of the sensing resistor RS is coupled to the sensing node NS to output a sensing potential VS to the microcontroller 295, and sense The second terminal of resistor RS is coupled to ground potential VSS.

The second output stage circuit 280 includes a sixth diode D6 and a second capacitor C2. The sixth diode D6 has an anode and a cathode, wherein the anode of the sixth diode D6 is coupled to the fifth node N5, and the cathode of the sixth diode D6 is coupled to the output node NOUT. The second capacitor C2 has a first terminal and a second terminal, wherein the first terminal of the second capacitor C2 is coupled to the output node NOUT, and the second terminal of the second capacitor C2 is coupled to the common node NCM. In some embodiments, an output current IOUT may flow through the sixth diode D6 and the second capacitor C2.

The third output stage circuit 290 includes a seventh diode D7 and a third capacitor C3. The seventh diode D7 has an anode and a cathode, wherein the anode of the seventh diode D7 is coupled to the sixth node N6, and the cathode of the seventh diode D7 is coupled to a supply node NP to output A supply potential VP to the microcontroller 295. The third capacitor C3 has a first terminal and a second terminal, wherein the first terminal of the third capacitor C3 is coupled to the supply node NP, and the second terminal of the third capacitor C3 is coupled to the ground potential VSS.

The microcontroller 295 may include various circuits, such as a detection circuit, a storage circuit, an averaging circuit, a comparison circuit, or/and a control circuit (not shown), but is not limited thereto. The microcontroller 295 can be powered by the supply potential VP, and can generate the second clock potential VA2. In some embodiments, the microcontroller 295 can calculate an average current IAV passing through the second power switch 270 according to the sensing potential VS, where the average current IAV can be approximately proportional to the output current IOUT. Specifically, the microcontroller 295 can first obtain an average value of the sensing potential VS, and then divide this average value by a predetermined resistance value (for example: the resistance value of the sensing resistor RS), thereby calculating the aforementioned Average current IAV. For example, the relationship between the average current IAV and the output current IOUT can be described in Table 1 below: Average current IAV Output current IOUT load ratio 0mA 0A 0% 1.3mA 1.7A 10% 2.6mA 3.4A 20% 3.9mA 5.1A 30% 5.2mA 6.8A 40% 6.5mA 8.5A 50% 7.8mA 10.2A 60% 9.1mA 11.9A 70% 10.4mA 13.6A 80% 11.7mA 15.3A 90% 13mA 17A 100% Table 1: Relationship between average current IAV and output current IOUT

In some embodiments, a current comparison table (for example, the aforementioned table 1) can be stored in the microcontroller 295 in advance, so that the microcontroller 295 can obtain the output current IOUT according to the average current IAV. In addition, the microcontroller 295 can also calculate the current output potential VOUT by analyzing the supply potential VP. Therefore, the microcontroller 295 will be able to estimate the output power PW of one of the power supplies 200 based on the supply potential VP and the average current IAV. Then, the microcontroller 295 can also compare the output power PW with a threshold value PTH. For example, the aforementioned critical value PTH may be approximately 70W, but is not limited thereto. In some embodiments, if the output power PW is higher than or equal to the threshold value PTH, the microcontroller 295 will output a notification potential VN with a low logic level to the pulse width modulation integrated circuit 230; otherwise, if When the output power PW is lower than the critical value PTH, the microcontroller 295 can output the notification potential VN with a high logic level to the pulse width modulation integrated circuit 230 .

In some embodiments, the feedback compensation circuit 250 includes a voltage regulator 252, a linear optical coupler 254, a switching transistor MS, a fourth capacitor C4, a fifth capacitor C5, and a first resistor R1. and a second resistor R2.

The first resistor R1 has a first terminal and a second terminal, wherein the first terminal of the first resistor R1 is coupled to the third node N3 to receive the intermediate potential VE, and the second terminal of the first resistor R1 It is coupled to a seventh node N7. The second resistor R2 has a first terminal and a second terminal, wherein the first terminal of the second resistor R2 is coupled to the seventh node N7, and the second terminal of the second resistor R2 is coupled to the ground. Potential VSS. The fourth capacitor C4 has a first terminal and a second terminal, wherein the first terminal of the fourth capacitor C4 is coupled to an eighth node N8, and the second terminal of the fourth capacitor C4 is coupled to the seventh node. N7.

In some embodiments, voltage regulator 252 is implemented with a TL431 electronic component. The voltage regulator 252 has an anode, a cathode, and a reference terminal. The anode of the voltage regulator 252 is coupled to the ground potential VSS, and the cathode of the voltage regulator 252 is coupled to the eighth node N8. The reference terminal of 252 is coupled to the seventh node N7.

In some embodiments, linear optocoupler 254 is implemented with a PC817 electronic component. The linear optical coupler 254 includes a light-emitting diode DL and a bicarrier junction transistor Q3 (for example, NPN type). The light-emitting diode DL has an anode and a cathode, wherein the anode of the light-emitting diode DL is coupled to a ninth node N9, and the cathode of the light-emitting diode DL is coupled to the eighth node N8. The bipolar junction transistor Q3 has a collector and an emitter, wherein the collector of the bipolar junction transistor Q3 is used to output the feedback potential VF to the pulse width modulation integrated circuit 230, and the bipolar junction transistor Q3 The emitter of carrier junction transistor Q3 is coupled to a tenth node N10.

The fifth capacitor C5 has a first terminal and a second terminal, wherein the first terminal of the fifth capacitor C5 is coupled to the tenth node N10 , and the second terminal of the fifth capacitor C5 is coupled to the ground potential VSS. For example, the switching transistor MS can be an N-type metal oxide semiconductor field effect transistor. The switching transistor MS has a control terminal (for example: a gate), a first terminal (for example: a source), and a second terminal (for example: a drain), wherein the control terminal of the switching transistor MS is For receiving a control potential VC, the first terminal of the switching transistor MS is coupled to the ninth node N9, and the second terminal of the switching transistor MS is coupled to the third node N3. In some embodiments, the pulse width modulation integrated circuit 230 can further determine the first clock potential VA1 and the control potential VC according to the notification potential VN from the microcontroller 295 .

Figure 3 shows a potential waveform diagram of the power supply 200 according to an embodiment of the present invention. According to the measurement results in Figure 3, the power supply 200 can operate in a first stage T1 or a second stage T2, and the operating principles thereof can be described as follows.

During the first stage T1, because it is determined that the output power PW is higher than or equal to the threshold value PTH, the microcontroller 295 outputs the notification potential VN with a low logic level to the pulse width modulation integrated circuit 230. In response to the aforementioned notification potential VN, the pulse width modulation integrated circuit 230 can normally output the first clock potential VA1 (for example, it has a switching frequency of 65kHz), and can generate a control potential VC with a high logic level. So as to enable feedback compensation circuit 250. At this time, the power factor corrector of the power supply 200 will operate normally.

During the second stage T2, because it is determined that the output power PW is lower than the threshold value PTH, the microcontroller 295 outputs the notification potential VN with a high logic level to the pulse width modulation integrated circuit 230. In response to the aforementioned notification potential VN, the pulse width modulation integrated circuit 230 can stop outputting the first clock potential VA1 (for example, it can be maintained at a low logic level) to disable the first power switch 220, and can A control potential VC with a low logic level is generated to disable the feedback compensation circuit 250 . At this time, since the power factor corrector of the power supply 200 also temporarily stops operating, the overall conversion efficiency of the power supply 200 can be greatly improved.

The present invention proposes a novel power supply that can automatically adjust its internal circuit according to real-time output conditions. According to actual measurement results, using the power supply designed as mentioned above can effectively improve the overall conversion efficiency, so it is very suitable for use in various devices.

It is worth noting that the above-mentioned potential, current, resistance value, inductance value, capacitance value, and other component parameters are not limiting conditions of the present invention. Designers can adjust these settings according to different needs. The power supply of the present invention is not limited to the state shown in Figures 1-3. The present invention may only include any one or multiple features of any one or multiple embodiments of Figures 1-3. In other words, not all features shown in the figures need to be implemented in the power supply of the present invention at the same time. Although the embodiment of the present invention uses a metal oxide semi-field effect transistor as an example, the present invention is not limited thereto. Those skilled in the art can use other types of transistors, such as junction field effect transistors or fins. type field effect transistor, etc., without affecting the effect of the present invention.

The ordinal numbers in this specification and the scope of the patent application, such as "first", "second", "third", etc., have no sequential relationship with each other. They are only used to distinguish two items with the same Different components with names.

Although the present invention is disclosed above in terms of preferred embodiments, they are not intended to limit the scope of the present invention. Anyone skilled in the art can make slight changes 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:Power supply

110,210: Bridge rectifier

120,220: First power switcher

130,230: Pulse width modulation integrated circuit

140,240: First output stage circuit

150,250: Feedback compensation circuit

160,260:Transformer

161,261: Main coil

162,262: Secondary coil

163,263: Auxiliary coil

170,270: Second power switch

180,280: Second output stage circuit

190,290: Third output stage circuit

195,295:Microcontroller

252:Voltage regulator

254:Linear Optocoupler

C1: first capacitor

C2: Second capacitor

C3: The third capacitor

C4: The fourth capacitor

C5: fifth capacitor

D1: first diode

D2: Second diode

D3: The third diode

D4: The fourth diode

D5: The fifth diode

D6: The sixth diode

D7: The seventh diode

DL: light emitting diode

IAV: average current

IOUT: output current

LU: Boost inductor

LM: Magnetizing inductor

M1: the first transistor

M2: Second transistor

MS: switching transistor

N1: first node

N2: second node

N3: The third node

N4: fourth node

N5: fifth node

N6: The sixth node

N7: The seventh node

N8: The eighth node

N9: Ninth node

N10: tenth node

NCM: common node

NIN1: first input node

NIN2: second input node

NOUT: output node

NP: supply node

NS: sensing node

PW: output power

PTH: critical value

Q3: Bicarrier junction transistor

R1: first resistor

R2: second resistor

RS: sensing resistor

T1: first stage

T2: first stage

VA1: first clock potential

VA2: second clock potential

VC: control potential

VIN1: first input potential

VIN2: second input potential

VE: intermediate potential

VF: feedback potential

VN: Notification potential

VOUT: output potential

VP: supply potential

VR: rectifier potential

VS: sensing potential

VSS: ground potential

Figure 1 is a schematic diagram of a power supply according to an embodiment of the present invention. Figure 2 is a circuit diagram showing a power supply according to an embodiment of the present invention. Figure 3 shows a potential waveform diagram of a power supply according to an embodiment of the present invention.

100:Power supply

110: Bridge rectifier

120:First power switcher

130: Pulse width modulation integrated circuit

140: First output stage circuit

150:Feedback compensation circuit

160:Transformer

161: Main coil

162: Secondary coil

163: Auxiliary coil

170:Second power switcher

180: Second output stage circuit

190: The third output stage circuit

195:Microcontroller

LU: Boost inductor

VA1: first clock potential

VA2: second clock potential

VIN1: first input potential

VIN2: second input potential

VE: intermediate potential

VF: feedback potential

VN: Notification potential

VOUT: output potential

VP: supply potential

VR: rectifier potential

VS: sensing potential

VSS: ground potential

Claims (9)

A power supply with high conversion efficiency includes: a bridge rectifier that generates a rectified potential based on a first input potential and a second input potential; a boost inductor that receives the rectified potential; and a first power switch , selectively coupling the boost inductor to a ground potential based on a first clock potential; a pulse width modulation integrated circuit generating the first clock potential based on a feedback potential; The first output stage circuit is coupled to the boost inductor and generates an intermediate potential; a feedback compensation circuit generates the feedback potential according to the intermediate potential; a transformer includes a main coil and a secondary coil, and an auxiliary coil, wherein the main coil is used to receive the intermediate potential; a second power switch to selectively couple the main coil to the ground potential according to a second clock potential; a second output A stage circuit is coupled to the auxiliary coil and generates an output potential; a third output stage circuit is coupled to the auxiliary coil and generates a supply potential; and a microcontroller generates the second clock potential, and detecting a sensing potential from the second power switch, wherein the microcontroller further selectively enables or disables the feedback compensation circuit according to the supply potential and the sensing potential; The microcontroller first calculates an average current through the second power switch based on the sensing potential, and then estimates an output power of the power supply based on the supply potential and the average current, and wherein If the output power is lower than a threshold value, the microcontroller will control the pulse width modulation integrated circuit to simultaneously disable the first power switch and the feedback compensation circuit. The power supply of claim 1, wherein the bridge rectifier includes: a first diode having an anode and a cathode, wherein the anode of the first diode is coupled to a first input node. Receive the first input potential, and the cathode of the first diode is coupled to a first node to output the rectified potential; a second diode has an anode and a cathode, wherein the second diode The anode of the pole body is coupled to a second input node to receive the second input potential, and the cathode of the second diode is coupled to the first node; a third diode has a an anode and a cathode, wherein the anode of the third diode is coupled to the ground potential and the cathode of the third diode is coupled to the first input node; and a fourth diode , having an anode and a cathode, wherein the anode of the fourth diode is coupled to the ground potential, and the cathode of the fourth diode is coupled to the second input node; wherein the boost The inductor has a first end and a second end, the first end of the boost inductor is coupled to the first node to receive the rectified potential, and the second end of the boost inductor is coupled to a second node. The power supply of claim 2, wherein the first power switch includes: a first transistor having a control terminal, a first terminal, and a second terminal, wherein the control terminal of the first transistor For receiving the first clock potential, the first terminal of the first transistor is coupled to the ground potential, and the second terminal of the first transistor is coupled to the second node. The power supply of claim 2, wherein the first output stage circuit includes: a fifth diode having an anode and a cathode, wherein the anode of the fifth diode is coupled to the second node , and the cathode of the fifth diode is coupled to a third node to output the intermediate potential; and a first capacitor has a first terminal and a second terminal, wherein the first terminal of the first capacitor One terminal is coupled to the third node, and the second terminal of the first capacitor is coupled to the ground potential. The power supply of claim 4, wherein the transformer further builds a magnetizing inductor, the main coil has a first end and a second end, and the first end of the main coil is coupled to the third node To receive the intermediate potential, the second end of the main coil is coupled to a fourth node, the exciting inductor has a first end and a second end, and the first end of the exciting inductor is coupled to The third node, the second end of the exciting inductor are coupled to the fourth node, the secondary coil has a first end and a second end, the first end of the secondary coil is coupled to a The fifth node, the second end of the auxiliary coil is coupled to a common node, the auxiliary coil has a first end and a second end, the auxiliary line The first end of the coil is coupled to a sixth node, and the second end of the auxiliary coil is coupled to the ground potential. The power supply of claim 5, wherein the second power switch includes: a second transistor having a control terminal, a first terminal, and a second terminal, wherein the control terminal of the second transistor is used to receive the second clock potential, the first terminal of the second transistor is coupled to a sensing node, and the second terminal of the second transistor is coupled to the fourth node; and a sensing resistor having a first terminal and a second terminal, wherein the first terminal of the sensing resistor is coupled to the sensing node to output the sensing potential to the microcontroller, and The second terminal of the sense resistor is coupled to the ground potential. The power supply of claim 5, wherein the second output stage circuit includes: a sixth diode having an anode and a cathode, wherein the anode of the sixth diode is coupled to the fifth node , and the cathode of the sixth diode is coupled to an output node to output the output potential; and a second capacitor has a first terminal and a second terminal, wherein the first terminal of the second capacitor A terminal is coupled to the output node, and the second terminal of the second capacitor is coupled to the common node. The power supply of claim 5, wherein the third output stage circuit includes: A seventh diode having an anode and a cathode, wherein the anode of the seventh diode is coupled to the sixth node, and the cathode of the seventh diode is coupled to a supply node to output the supply potential to the microcontroller; and a third capacitor having a first terminal and a second terminal, wherein the first terminal of the third capacitor is coupled to the supply node, and the third capacitor has a first terminal and a second terminal. The second terminal of the capacitor is coupled to the ground potential. The power supply of claim 5, wherein the feedback compensation circuit includes: a first resistor having a first terminal and a second terminal, wherein the first terminal of the first resistor is coupled to the The third node is to receive the intermediate potential, and the second end of the first resistor is coupled to a seventh node; a second resistor has a first end and a second end, wherein the second The first terminal of the resistor is coupled to the seventh node, and the second terminal of the second resistor is coupled to the ground potential; a fourth capacitor has a first terminal and a second terminal , wherein the first terminal of the fourth capacitor is coupled to an eighth node, and the second terminal of the fourth capacitor is coupled to the seventh node; a voltage regulator having an anode and a cathode , and a reference terminal, wherein the anode of the voltage regulator is coupled to the ground potential, the cathode of the voltage regulator is coupled to the eighth node, and the reference terminal of the voltage regulator is coupled to the seventh node; a linear optical coupler including a light-emitting diode and a bicarrier junction transistor, wherein the light-emitting diode has an anode and a cathode, and the anode of the light-emitting diode is Coupled to a ninth node, the cathode of the light-emitting diode is coupled to the eighth node, the bipolar junction transistor has a collector and an emitter, the bipolar junction transistor The collector is used to output the feedback potential to the pulse width modulation integrated circuit, and the emitter of the bipolar junction transistor is coupled to a tenth node; a fifth capacitor, having a first terminal and a second terminal, wherein the first terminal of the fifth capacitor is coupled to the tenth node, and the second terminal of the fifth capacitor is coupled to the ground potential; and a A switching transistor has a control terminal, a first terminal, and a second terminal, wherein the control terminal of the switching transistor is used to receive a control potential, and the first terminal of the switching transistor is coupled to The ninth node, and the second terminal of the switching transistor is coupled to the third node; wherein the pulse width modulation integrated circuit further determines the first voltage according to a notification potential from the microcontroller. clock potential and the control potential.

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