TW202343942A - Power supply device - Google Patents

Abstract

A power supply device includes a bridge rectifier, a transformer, a power switch element, an output stage circuit, a feedback circuit, and a PWM (Pulse Width Modulation) IC (Integrated Circuit). The bridge rectifier generates a rectified voltage according to a first input voltage and a second input voltage. The transformer includes a main coil, a secondary coil, and an auxiliary coil. A magnetizing inductor is built in the transformer. The main coil receives the rectified voltage. The output stage circuit is coupled to the secondary coil, and generates an output voltage. If a protection mechanism of the power supply device is triggered, the PWM IC will operates in a latch stage, a shutdown standby stage, and a shutdown stage one after another. In the shutdown stage, a supply voltage of the PWM IC is reduced to 0.

Description

power supply

The present invention relates to a power supply, and in particular to a power supply capable of reducing power consumption.

Currently, there are two types of protection mechanisms for power supplies. One is a latch-off design, and the other is an automatic recovery (Auto Recovery) design. The latch-off protection mechanism has a shortcoming. That is to say, when a fault occurs, the relevant controller will still consume some power, resulting in a reduction in overall operating efficiency. 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 that includes: a bridge rectifier that generates a rectified potential based on a first input potential and a second input potential; a transformer that includes a primary coil and a secondary coil , and an auxiliary coil, wherein the transformer has a built-in exciting inductor, and the main coil is used to receive the rectified potential; a power switch selectively switches the main coil according to a pulse width modulation potential. coupled to a ground potential; an output stage circuit coupled to the auxiliary coil and generating an output potential; a feedback circuit coupled to the auxiliary coil; and a pulse width modulation integrated circuit coupled to to the feedback circuit and generate the PWM potential; and if a protection mechanism of the power supply is triggered, the PWM integrated circuit will operate in a latch phase, A shutdown preparation phase, and a shutdown phase; in the shutdown phase, a supply potential of the pulse width modulation integrated circuit is reduced to 0.

In some embodiments, the supply potential of the PWM IC oscillates during the latch phase.

In some embodiments, during the shutdown preparation phase, the supply potential of the PWM IC is maintained at a lower level.

In some embodiments, 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 to 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 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 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.

In some embodiments, the main coil has a first end and a second end, the first end of the main coil is coupled to the first node to receive the rectified potential, and the second end of the main coil is coupled to a second node, the exciting inductor has a first end and a second end, the first end of the exciting inductor is coupled to the first node, and the second end of the exciting inductor The terminal is coupled to the second node, the secondary coil has a first terminal and a second terminal, the first terminal of the secondary coil is coupled to a third node, and the second terminal of the secondary coil is Coupled to a common node, the auxiliary coil has a first end and a second end, the first end of the auxiliary coil is coupled to a fourth node, and the second end of the auxiliary coil is coupled to to this ground potential.

In some embodiments, the power switch includes: a transistor having a control terminal, a first terminal, and a second terminal, wherein the control terminal of the transistor is used to receive the pulse width modulation potential, the first terminal of the transistor is coupled to a fifth node, and the second terminal of the transistor is coupled to the second node.

In some embodiments, the power supply further includes: a sensing resistor having a first terminal and a second terminal, wherein the first terminal of the sensing resistor is coupled to the fifth node to A sensing potential is output, and the second end of the sensing resistor is coupled to the ground potential.

In some embodiments, if it is detected that the sensing potential is higher than or equal to a critical potential, the PWM integrated circuit determines that the protection mechanism of the power supply has been triggered.

In some embodiments, the output stage circuit includes: a fifth diode having an anode and a cathode, wherein the anode of the fifth diode is coupled to the third node, and the fifth second The cathode of the pole body is coupled to an output node to output the output potential; and a first capacitor has a first terminal and a second terminal, wherein the first terminal of the first capacitor is coupled to the output node, and the second terminal of the first capacitor is coupled to the common node.

In some embodiments, the feedback circuit includes: a sixth diode having an anode and a cathode, wherein the anode of the sixth diode is coupled to the fourth node, and the sixth second The cathode of the pole body is coupled to a supply node of the pulse width modulation integrated circuit; and a second capacitor has a first terminal and a second terminal, wherein the first terminal of the second capacitor is coupled to the supply node, and the second terminal of the second capacitor is coupled to the ground potential.

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 transformer 120, a power switch 130, an output stage circuit 140, a feedback circuit 150, and a pulse width modulation integrated circuit. (Pulse Width Modulation Integrated Circuit, PWM IC)160. 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 value of the AC voltage can be about 90V to 264V, but it is not limited thereto. The transformer 120 includes a primary coil 121, a secondary coil 122, and an auxiliary coil 123. The transformer 120 may have a built-in magnetizing inductor LM. The primary coil 121 , the auxiliary coil 123 , and the exciting inductor LM may be located on the same side of the transformer 120 , while the secondary coil 122 may be located on the opposite side of the transformer 120 . The primary coil 121 can receive the rectified potential VR, and in response to the rectified potential VR, the secondary coil 122 and the auxiliary coil 123 can generate respective induced potentials. The power switch 130 can selectively couple the main coil 121 to a ground potential VSS (eg, 0V) according to a pulse width modulation potential VA. For example, if the pulse width modulation potential VA is a high logic level (ie, logic “1”), the power switch 130 can couple the main coil 121 to the ground potential VSS (ie, the power switch 130 can be approximated as a short-circuit path); on the contrary, if the pulse width modulation potential VA is a low logic level (that is, logic "0"), the power switch 130 will not couple the main coil 121 to the ground potential. VSS (ie, power switch 130 may approximate an open path). The output stage circuit 140 is coupled to the secondary coil 122 and can generate an output potential VOUT. For example, the output potential VOUT may be a DC potential, and its potential level may be from 18V to 22V, but is not limited thereto. The feedback circuit 150 is coupled to the auxiliary coil 123 . The pulse width modulation integrated circuit 160 is coupled to the feedback circuit 150 and can generate the pulse width modulation potential VA. For example, the pulse width modulation integrated circuit 160 may be powered by the feedback circuit 150 . If a protection mechanism of the power supply 100 is triggered, the PWM integrated circuit 160 will operate in a latch stage (Latch Stage) T1, a shutdown standby stage (Shutdown Standby Stage) T2, and a Shutdown Stage (Shutdown Stage) T3. In some embodiments, the aforementioned protection mechanism may include over-voltage protection, over-current protection, or/and over-temperature protection. In detail, during the latch phase T1, the supply potential VCC of one of the pulse width modulation integrated circuits 160 may oscillate. During the shutdown preparation phase T2, the supply potential VCC of the pulse width modulation integrated circuit 160 may be maintained at a lower level. During the shutdown phase T3, the supply potential VCC of the pulse width modulation integrated circuit 160 may decrease to 0. Since the PWM IC 160 can be completely shut down during the protection mechanism of the power supply 100, the overall power consumption of the power supply 100 can be greatly reduced.

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 schematic 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 transformer 220, and a power switch 230. , an output stage circuit 240, a feedback circuit 250, and a pulse width modulation integrated circuit 260. 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 230 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 the 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 transformer 220 includes a primary coil 221, a secondary coil 222, and an auxiliary coil 223, wherein the transformer 220 may have a built-in magnetizing inductor LM. The exciting inductor LM may be an inherent component produced when the transformer 220 is manufactured, and is not an external independent component. The main coil 221, the auxiliary coil 223, and the exciting inductor LM can be located on the same side of the transformer 220 (for example, the primary side), while the secondary coil 222 can be located on the opposite side of the transformer 220 (for example, the secondary side). can be isolated from the primary side). The main coil 221 has a first end and a second end, wherein the first end of the main coil 221 is coupled to the first node N1 to receive the rectified potential VR, and the second end of the main coil 221 is coupled to a first node N1. Two nodes N2. 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 first node N1, and the second end of the exciting inductor LM is coupled to the second node N2 . The secondary coil 222 has a first end and a second end, wherein the first end of the secondary coil 222 is coupled to a third node N3, and the second end of the secondary coil 222 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 223 has a first end and a second end, wherein the first end of the auxiliary coil 223 is coupled to a fourth node N4, and the second end of the auxiliary coil 223 is coupled to the ground potential VSS.

The power switch 230 includes a transistor M1. For example, the transistor M1 may be an N-type MOSFET. The 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 transistor M1 is used for Receiving a pulse width modulation potential VA, the first terminal of the transistor M1 is coupled to a fifth node N5, and the second terminal of the transistor M1 is coupled to the second node N2. For example, if the pulse width modulation potential VA is a high logic level, the transistor M1 will be enabled; conversely, if the pulse width modulation potential VA is a low logic level, the transistor M1 will be enabled. Disabled.

The 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 third node N3, and the cathode of the fifth diode D5 is coupled to the output node NOUT. 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 output node NOUT, and the second terminal of the first capacitor C1 is coupled to the common node NCM.

The feedback circuit 250 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 fourth node N4, and the cathode of the sixth diode D6 is coupled to the pulse width modulation product. One of the bulk circuits 260 supplies node NS. 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 supply node NS, and the second terminal of the second capacitor C2 is coupled to the ground potential VSS.

The pulse width modulation integrated circuit 260 can generate the aforementioned pulse width modulation potential VA. The pulse width modulation integrated circuit 260 may be powered by a supply potential VCC at the supply node NS. Specifically, if the supply potential VCC is a high logic level, the pulse width modulation integrated circuit 260 will be activated and output the pulse width modulation potential VA; conversely, if the supply potential VCC is a low logic level, Then the pulse width modulation integrated circuit 260 will be turned off and stop outputting the pulse width modulation potential VA.

In some embodiments, the power supply 200 further includes a sensing resistor RS, which has a very small resistance value. The sensing resistor RS has a first terminal and a second terminal, wherein the first terminal of the sensing resistor RS is coupled to the fifth node N5 to output a sensing potential VE, and the third terminal of the sensing resistor RS The two terminals are coupled to ground potential VSS. The pulse width modulation integrated circuit 260 is coupled to the fifth node N5 and continuously monitors the sensing potential VE. For example, if the sensing potential VE is detected to be lower than a critical potential VTH, the pulse width modulation integrated circuit 260 can determine that the protection mechanism of the power supply 200 has not been triggered; conversely, if the sensing potential VE is detected is higher than or equal to the critical potential VTH, the pulse width modulation integrated circuit 260 can determine that the protection mechanism of the power supply 200 has been triggered. It must be understood that the sensing resistor RS is an optional component and may be replaced by a short-circuit path in other embodiments.

Figure 3 is a waveform diagram showing the supply potential VCC of a pulse width modulation integrated circuit of a conventional power supply, in which the horizontal axis represents time and the vertical axis represents potential level. As shown in Figure 3, at a trigger time point TG, the latch-closed protection mechanism is triggered. At this time, the supply potential VCC of the pulse width modulation integrated circuit begins to discharge. However, after a long period of time, the supply potential VCC will remain at a predetermined level VK, so the pulse width modulation integrated circuit of the traditional power supply still has a relatively high power consumption.

Figure 4 is a waveform diagram showing the supply potential VCC of the pulse width modulation integrated circuit 260 of the power supply 200 according to an embodiment of the present invention, in which the horizontal axis represents time and the vertical axis represents the potential level. As shown in FIG. 4 , if no protection mechanism is triggered, the feedback circuit 250 can provide power to the pulse width modulation integrated circuit 260 so that the supply potential VCC of the pulse width modulation integrated circuit 260 can be maintained. On a higher level VH. At a triggering time point TG, the latch closing protection mechanism is triggered. At this time, the output potential VOUT will drop to 0, the feedback circuit 250 will stop providing power, and the supply potential VCC of the pulse width modulation integrated circuit 260 will start to discharge. It must be noted that after the latch-off protection mechanism is triggered, the supply potential VCC at the supply node NS will only be controlled by the pulse width modulation integrated circuit 260. Then, the PWM integrated circuit 260 may operate in a latch phase T1, a shutdown preparation phase T2, and a shutdown phase T3. Specifically, during the latch phase T1, the supply potential VCC of the pulse width modulation integrated circuit 260 will oscillate up and down due to repeated tests to see whether circuit faults still occur. If a circuit fault is confirmed and a latch-off protection mechanism must be used, the supply potential VCC of the pulse width modulation integrated circuit 260 will further decrease. Then, during the shutdown preparation phase T2, the supply potential VCC of the pulse width modulation integrated circuit 260 can be maintained at a lower level VL. Finally, during the shutdown phase T3, the supply potential VCC of the pulse width modulation integrated circuit 260 will decrease to 0 (or the ground potential VSS). In other words, the power supply 200 proposed by the present invention can quickly and completely shut down the pulse width modulation integrated circuit 260 after the protection mechanism is triggered. According to actual measurement results, this design can significantly reduce the overall power consumption of the power supply 200.

In some embodiments, component parameters of the power supply 200 may be as follows. The inductance value of the magnetizing inductor LM can be between 351μH and 429μH, preferably 390μH. The capacitance value of the first capacitor C1 may be between 544 μF and 816 μF, preferably 680 μF. The capacitance value of the second capacitor C2 can be between 3.76μF and 5.64μF, preferably 4.7μF. The resistance value of the sensing resistor RS can be between 0.25Ω and 0.5Ω. The critical potential VTH can be between 3V and 4V. The lower level VL may be approximately 30% of the higher level VH. The turns ratio of the primary coil 221 to the secondary coil 222 can be between 1 and 100, preferably 20. The turns ratio of the main coil 221 to the auxiliary coil 223 can be between 1 and 100, preferably 10. The duration of the latching phase T1 can be between 0.2ms and 0.6ms, preferably 0.4ms. The duration of the shutdown preparation phase T2 is between 0.6ms and 1.4ms, preferably 1ms. The above parameter range is obtained based on the results of multiple experiments, which helps minimize the power consumption of the power supply 200 while maximizing the conversion efficiency of the power supply 200 .

The present invention proposes a novel power supply. According to actual measurement results, the power supply using the above design can quickly shut down the pulse width modulation integrated circuit after the protection mechanism is triggered to reduce power consumption, so it is very suitable for use in various electronic 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 1-4. The present invention may only include any one or multiple features of any one or multiple embodiments of Figures 1-4. 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:Transformer 121,221: Main coil 122,222: Secondary coil 123,223: Auxiliary coil 130,230:Power switcher 140,240: Output stage circuit 150,250: Feedback circuit 160,260: Pulse width modulation integrated circuit C1: first capacitor C2: Second capacitor D1: first diode D2: Second diode D3: The third diode D4: The fourth diode D5: The fifth diode D6: The sixth diode LM: Magnetizing inductor M1: transistor N1: first node N2: second node N3: The third node N4: fourth node N5: fifth node NCM: common node NIN1: first input node NIN2: second input node NOUT: output node NS: supply node RS: sensing resistor T1:Latching stage T2: Shutdown preparation stage T3: shutdown stage TG: trigger time point VA: pulse width modulation potential VCC: supply potential VE: sensing potential VH: higher level VIN1: first input potential VIN2: second input potential VK: established positioning VL: lower level VOUT: output potential VR: rectifier potential VSS: ground potential VTH: critical potential

Figure 1 is a schematic diagram of a power supply according to an embodiment of the present invention. Figure 2 is a schematic diagram of a power supply according to an embodiment of the present invention. Figure 3 is a waveform diagram showing the supply potential of a pulse width modulation integrated circuit of a conventional power supply. FIG. 4 is a waveform diagram showing the supply potential of the pulse width modulation integrated circuit of the power supply according to an embodiment of the present invention.

100:Power supply

110: Bridge rectifier

120:Transformer

121: Main coil

122: Secondary coil

123: Auxiliary coil

130:Power switcher

140:Output stage circuit

150:Feedback circuit

160:Pulse width modulation integrated circuit

LM: Magnetizing inductor

T1:Latching stage

T2: Shutdown preparation stage

T3: shutdown stage

VA: pulse width modulation potential

VCC: supply potential

VIN1: first input potential

VIN2: second input potential

VOUT: output potential

VR: rectifier potential

VSS: ground potential

Claims (10)

A power supply including: A bridge rectifier generates a rectified potential based on a first input potential and a second input potential; A transformer, including a main coil, a secondary coil, and an auxiliary coil, wherein the transformer has a built-in exciting inductor, and the main coil is used to receive the rectified potential; a power switch that selectively couples the main coil to a ground potential based on a pulse width modulated potential; An output stage circuit is coupled to the secondary coil and generates an output potential; a feedback circuit coupled to the auxiliary coil; and A pulse width modulation integrated circuit is coupled to the feedback circuit and generates the pulse width modulation potential; If a protection mechanism of the power supply is triggered, the pulse width modulation integrated circuit will operate in a latch phase, a shutdown preparation phase, and a shutdown phase successively; During the shutdown phase, the supply potential of one of the PWM integrated circuits decreases to 0. For example, the power supply of claim 1, wherein during the latch phase, the supply potential of the pulse width modulation integrated circuit oscillates. For example, the power supply of claim 1, wherein during the shutdown preparation phase, the supply potential of the pulse width modulation integrated circuit is maintained at a lower level. 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 to receive the first input potential, and the first diode The cathode is coupled to a first node to output the rectified potential; a second diode having an anode and a cathode, wherein the anode of the second diode is coupled to a second input node to receive the second input potential, and the The cathode is coupled to the first node; a third diode having 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. The power supply of claim 4, wherein the main coil has a first end and a second end, the first end of the main coil is coupled to the first node to receive the rectified potential, and the main coil has a first end and a second end. The second terminal is coupled to a second node, the magnetizing inductor has a first terminal and a second terminal, the first terminal of the magnetizing inductor is coupled to the first node, and the magnetizing inductor The second end is coupled to the second node, the secondary coil has a first end and a second end, the first end of the secondary coil is coupled to a third node, and the secondary coil has a first end and a second end. The second end is coupled to a common node, the auxiliary coil has a first end and a second end, the first end of the auxiliary coil is coupled to a fourth node, and the second end of the auxiliary coil The terminals are coupled to this ground potential. The power supply of claim 5, wherein the power switch includes: A transistor has a control terminal, a first terminal, and a second terminal, wherein the control terminal of the transistor is used to receive the pulse width modulation potential, and the first terminal of the transistor is is coupled to a fifth node, and the second terminal of the transistor is coupled to the second node. For example, the power supply of claim 6 further includes: A sensing resistor has a first terminal and a second terminal, wherein the first terminal of the sensing resistor is coupled to the fifth node to output a sensing potential, and the sensing resistor The second terminal is coupled to the ground potential. For example, in the power supply of claim 7, if it is detected that the sensing potential is higher than or equal to a critical potential, the pulse width modulation integrated circuit determines that the protection mechanism of the power supply has been triggered. The power supply of claim 5, wherein the output stage circuit includes: a fifth diode having an anode and a cathode, wherein the anode of the fifth diode is coupled to the third node, and the cathode of the fifth diode is coupled to an output node to output the output potential; and a first capacitor having a first terminal and a second terminal, wherein the first terminal of the first capacitor is coupled to the output node, and the second terminal of the first capacitor is coupled to the common node. For example, the power supply of claim 5, wherein the feedback circuit includes: A sixth diode having an anode and a cathode, wherein the anode of the sixth diode is coupled to the fourth node, and the cathode of the sixth diode is coupled to the pulse wave One of the supply nodes of the width modulation integrated circuit; and a second capacitor having a first terminal and a second terminal, wherein the first terminal of the second capacitor is coupled to the supply node, and the second terminal of the second capacitor is coupled to the ground Potential.

Images