TWI879605B - Power supply device with high output stability - Google Patents

Abstract

A power supply device with high output stability includes a bridge rectifier, a first capacitor, a boost inductor, a first power switch element, a first output stage circuit, a first transformer, a second power switch element, a second output stage circuit, an asymmetric resonant converter, and a control circuit. The second output stage circuit generates an output voltage. The asymmetric resonant converter provides a supplementary voltage. The control circuit selectively couples asymmetric resonant converter to the second output stage circuit according to an external voltage.

Description

High output stability power supply

The present invention relates to a power supply, and more particularly to a power supply with high output stability.

The power supply is an indispensable component in the field of laptop computers. However, when the relevant system is operated in a heavy load mode, its battery components may not be properly charged by the power supply. In view of this, it is necessary to propose a new solution to overcome the difficulties faced by the previous technology.

In a preferred embodiment, the present invention provides a power supply with high output stability, comprising: a bridge rectifier, generating a rectified potential according to a first input potential and a second input potential; a first capacitor, storing the rectified potential; a boost inductor, receiving the rectified potential; a first power switch, selectively coupling the boost inductor to a ground potential according to a first driving potential; a first output stage circuit, coupled to the boost inductor and generating an intermediate potential; a first transformer, comprising a first main coil and a first secondary coil, wherein the first main coil is used to receive the intermediate potential; a second power switch; a first output stage circuit coupled to the boost inductor and generating an intermediate potential; a first transformer, comprising a first main coil and a first secondary coil, wherein the first main coil is used to receive the intermediate potential; and a second power switch; a first power switch; a first output stage circuit coupled to the boost inductor and generating an intermediate potential. A rate switch selectively couples the first main coil to the ground potential according to a second driving potential; a second output stage circuit coupled to the first secondary coil and generates an output potential; an asymmetric resonant converter provides a supplementary potential according to the rectified potential, a third driving potential, a fourth driving potential, and an external potential; and a control circuit generates the first driving potential, the second driving potential, the third driving potential, and the fourth driving potential according to a communication potential; wherein the control circuit further selectively couples the asymmetric resonant converter to the second output stage circuit according to the external potential.

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 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 cathode of the second diode 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 ground potential. The first input node 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 first capacitor has a first end and a second end, the first end of the first capacitor is coupled to the first node to store the rectified potential, and the second end of the first capacitor is coupled to the ground potential; wherein the boost 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.

In some embodiments, 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 second capacitor having a first end and a second end, wherein the first end of the second capacitor is coupled to the third node, and the second end of the second capacitor is coupled to the ground potential.

In some embodiments, the first transformer further has a built-in first excitation inductor, the first main coil has a first end and a second end, the first end of the first main coil is coupled to the third node to receive the intermediate potential, the second end of the first main coil is coupled to a fourth node, the first excitation inductor has a first end and a second end, the first end of the first excitation inductor is coupled to the third node, the second end of the first excitation inductor is coupled to the fourth node, the first secondary coil has a first end and a second end, the first end of the first secondary coil is coupled to a fifth node, and the second end of the first secondary coil is coupled to a common node.

In some embodiments, the first power switch includes: a first transistor having a control end, a first end, and a second end, wherein the control end of the first transistor is used to receive the first driving potential, the first end of the first transistor is coupled to the ground potential, and the second end of the first transistor is coupled to the second node; wherein the second power switch includes: a second transistor having a control end, a first end, and a second end, wherein the control end of the second transistor is used to receive the second driving potential, the first end of the second transistor is coupled to the ground potential, and the second end of the second transistor is coupled to the fourth node.

In some embodiments, 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 third capacitor having a first end and a second end, wherein the first end of the third capacitor is coupled to the output node, and the second end of the third capacitor is coupled to the common node.

In some embodiments, the asymmetric resonant converter includes: a third transistor having a control terminal, a first terminal, and a second terminal, wherein the control terminal of the third transistor is used to receive the third driving potential, the first terminal of the third transistor is coupled to a sixth node, and the second terminal of the third transistor is used to receive the rectified potential; a fourth transistor having a control terminal, a first terminal, and a second terminal, wherein the control terminal of the fourth transistor is used to receive the fourth driving potential, the first terminal of the fourth transistor is coupled to the ground potential, and the second terminal of the fourth transistor is coupled to the sixth node; a resonant inductor , having a first end and a second end, wherein the first end of the resonant inductor is coupled to the sixth node, and the second end of the resonant inductor is coupled to a seventh node; a resonant capacitor, having a first end and a second end, wherein the first end of the resonant capacitor is coupled to the seventh node, and the second end of the resonant capacitor is coupled to an eighth node; and a fifth transistor, having a control end, a first end, and a second end, wherein the control end of the fifth transistor is used to receive the external potential, the first end of the fifth transistor is coupled to the ground potential, and the second end of the fifth transistor is coupled to a ninth node.

In some embodiments, the asymmetric resonant converter further includes: a second transformer including a second main coil and a second secondary coil, wherein the second transformer further has a built-in second excitation inductor, the second main coil having a first end and a second end, the first end of the second main coil being coupled to the eighth node, the second end of the second main coil being coupled to the ninth node, the second excitation inductor having a first end and a second end, the first end of the second excitation inductor being coupled to the eighth node, the second end of the second excitation inductor being coupled to the ninth node, Two secondary coils have a first end and a second end, the first end of the second secondary coil is coupled to a tenth node, and the second end of the second secondary coil is coupled to a common node; a seventh diode has an anode and a cathode, wherein the anode of the seventh diode is coupled to the tenth node, and the cathode of the seventh diode is coupled to a supplementary node to output the supplementary potential; and a fourth capacitor has a first end and a second end, wherein the first end of the fourth capacitor is coupled to the supplementary node, and the second end of the fourth capacitor is coupled to the common node.

In some embodiments, the control circuit includes: a microcontroller, which generates the first driving potential, the second driving potential, the third driving potential, and the fourth driving potential according to the communication potential and the external potential; and an error amplifier, which is powered by the external potential and has a first input terminal, a second input terminal, and an output terminal, wherein the first input terminal of the error amplifier is used to receive the output potential, the second input terminal of the error amplifier is used to receive the supplementary potential, and the output terminal of the error amplifier is used to output a control potential.

In some embodiments, the control circuit further includes: a sixth transistor having a control end, a first end, and a second end, wherein the control end of the sixth transistor is used to receive the control potential, the first end of the sixth transistor is coupled to an output node, and the second end of the sixth transistor is coupled to a connection node; and a seventh transistor having a control end, a first end, and a second end, wherein the control end of the seventh transistor is used to receive the external potential, the first end of the seventh transistor is coupled to the connection node, and the second end of the seventh transistor is coupled to a supplement node to receive the supplement potential.

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

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

FIG. 1 is a schematic diagram showing 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 laptop computer, or an all-in-one computer. As shown in FIG. 1, the power supply 100 includes: a bridge rectifier 110, a first capacitor C1, a boost inductor LU, a first power switch 120, a first output stage circuit 130, a first transformer 140, a second power switch 150, a second output stage circuit 160, an asymmetric resonant converter 170, and a control circuit 190. 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 an AC voltage with any frequency and any amplitude can be formed between the first input potential VIN1 and the second input potential VIN2. For example, the frequency of the AC voltage can be approximately 50 Hz or 60 Hz, and the root mean square (RMS) value of the AC voltage can be between 90 V and 264 V, but is not limited thereto. The first capacitor C1 can be used to store the rectified potential VR. The boost inductor LU can be used to receive the rectified potential VR. The first power switch 120 can selectively couple the boost inductor LU to a ground potential VSS (e.g., 0 V) according to a first drive potential VG1. For example, if the first driving potential VG1 has a high logic level (i.e., logic "1"), the first power switch 120 can couple the boost inductor LU to the ground potential VSS (i.e., the first power switch 120 can be similar to a short circuit path); conversely, if the first driving potential VG1 has a low logic level (i.e., logic "0"), the first power switch 120 will not couple the boost inductor LU to the ground potential VSS (i.e., the first power switch 120 can be similar to a break path). The first output stage circuit 130 is coupled to the boost inductor LU, wherein the first output stage circuit 130 can be used to generate an intermediate potential VE.

The first transformer 140 includes a first main coil 141 and a first secondary coil 142, wherein the first main coil 141 may be located at one side of the first transformer 140, and the first secondary coil 142 may be located at the other side of the first transformer 140. The first main coil 141 may be used to receive the intermediate potential VE, and the first secondary coil 142 may operate according to the intermediate potential VE. The second power switch 150 may selectively couple the first main coil 141 to the ground potential VSS according to a second driving potential VG2. For example, if the second driving potential VG2 has a high logic level, the second power switch 150 can couple the first main coil 141 to the ground potential VSS (that is, the second power switch 150 can be similar to another short-circuit path); conversely, if the second driving potential VG2 has a low logic level, the second power switch 150 will not couple the first main coil 141 to the ground potential VSS (that is, the second power switch 150 can be similar to another open-circuit path). The second output stage circuit 160 is coupled to the first sub-coil 142 and can be used to generate an output potential. For example, the output potential VOUT can be a DC potential, and its potential level can be between 18V and 22V, but it is not limited thereto.

The asymmetric resonant converter 170 can provide a supplementary potential VA according to a rectified potential VR, a third driving potential VG3, a fourth driving potential VG4, and an external potential VX. For example, the supplementary potential VA can be substantially equal to the aforementioned output potential VOUT, but is not limited thereto. The control circuit 190 can generate a first driving potential VG1, a second driving potential VG2, a third driving potential VG3, and a fourth driving potential VG4 according to a communication potential VT. In addition, the control circuit 190 can also selectively couple the asymmetric resonant converter 170 to the second output stage circuit 160 according to the external potential VX. According to actual measurement results, even when used to drive a system operating in a heavy load mode, the power supply 100 of the present invention can still compensate for the output potential VOUT of the second output stage circuit 160 by using the compensation potential VA of the asymmetric resonant converter 170, thereby effectively maintaining the overall output stability.

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 present invention.

FIG. 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 first capacitor C1, a boost inductor LU, a first power switch 220, a first output stage circuit 230, a first transformer 240, a second power switch 250, a second output stage circuit 260, an asymmetric resonant converter 270, and a control circuit 290. The first input node NIN1 and the second input node NIN2 of the power supply 200 can receive a first input potential VIN1 and a second input potential VIN2 from an external input power source (not shown), respectively. The output node NOUT of the power supply 200 can be used to output an output potential VOUT to a system end (not shown), such as a laptop computer.

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 a 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 (e.g., 0V), 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 first capacitor C1 has a first terminal and a second terminal, wherein the first terminal of the first capacitor C1 is coupled to the first node N1 to store the rectified potential VR, and the second terminal of the first capacitor C1 is coupled to the ground potential VSS.

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 (e.g., a gate), a first terminal (e.g., a source), and a second terminal (e.g., a drain), wherein the control terminal of the first transistor M1 is used to receive a first driving potential VG1, 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 first output stage circuit 230 includes a fifth diode D5 and a second capacitor C2. 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 to output an intermediate potential VE. 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 third node N3, and the second terminal of the second capacitor C2 is coupled to the ground potential VSS.

The first transformer 240 includes a first main coil 241 and a first secondary coil 242, wherein the first transformer 240 may further have a built-in first excitation inductor LM1. The first excitation inductor LM1 may be an inherent component generated when the first transformer 240 is manufactured, and is not an external independent component. The first main coil 241 and the first excitation inductor LM1 may be located on the same side of the first transformer 240 (e.g., the primary side), and the first secondary coil 242 may be located on the other side of the first transformer 240 (e.g., the secondary side, which may be isolated from the primary side). In detail, the first main coil 241 has a first end and a second end, wherein the first end of the first main coil 241 is coupled to the third node N3 to receive the intermediate potential VE, and the second end of the first main coil 241 is coupled to a fourth node N4. The first excitation inductor LM1 has a first end and a second end, wherein the first end of the first excitation inductor LM1 is coupled to the third node N3, and the second end of the first excitation inductor LM1 is coupled to the fourth node N4. The first sub-coil 242 has a first end and a second end, wherein the first end of the first sub-coil 242 is coupled to a fifth node N5, and the second end of the first sub-coil 242 is coupled to a common node NCM. For example, the common node NCM can provide a common potential, which can be regarded as another ground potential, and can be the same as or different from the aforementioned ground potential VSS.

The second power switch 250 includes a second transistor M2. For example, the second transistor M2 may be an N-type metal oxide semi-conductor field effect transistor. The second transistor M2 has a control end (e.g., a gate), a first end (e.g., a source), and a second end (e.g., a drain), wherein the control end of the second transistor M2 is used to receive a second driving potential VG2, the first end of the second transistor M2 is coupled to the ground potential VSS, and the second end of the second transistor M2 is coupled to the fourth node N4.

The second output stage circuit 260 includes a sixth diode D6 and a third capacitor C3. 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 third capacitor C3 has a first terminal and a second terminal, wherein the first terminal of the third capacitor C3 is coupled to the output node NOUT, and the second terminal of the third capacitor C3 is coupled to the common node NCM.

Generally speaking, the asymmetric resonant converter 270 can be regarded as an auxiliary output stage circuit, which can be selectively coupled in parallel with the second output stage circuit 260, so as to improve the output stability of the power supply 200. The asymmetric resonant converter 270 includes: a second transformer 280, a third transistor M3, a fourth transistor M4, a fifth transistor M5, a seventh diode D7, a resonant inductor LR, a resonant capacitor CR, and a fourth capacitor C4. For example, the third transistor M3, the fourth transistor M4, and the fifth transistor M5 can each be an N-type metal oxide semi-conductor field effect transistor.

The third transistor M3 has a control terminal (e.g., a gate), a first terminal (e.g., a source), and a second terminal (e.g., a drain), wherein the control terminal of the third transistor M3 is used to receive a third driving potential VG3, the first terminal of the third transistor M3 is coupled to a sixth node N6, and the second terminal of the third transistor M3 is coupled to the first node N1 to receive the rectified potential VR. The fourth transistor M4 has a control terminal (e.g., a gate), a first terminal (e.g., a source), and a second terminal (e.g., a drain), wherein the control terminal of the fourth transistor M4 is used to receive a fourth driving potential VG4, the first terminal of the fourth transistor M4 is coupled to the ground potential VSS, and the second terminal of the fourth transistor M4 is coupled to the sixth node N6. In some embodiments, the third transistor M3 and the fourth transistor M4 may serve as a switching circuit of the asymmetric resonant converter 270. For example, the third driving potential VG3 and the fourth driving potential VG4 may have complementary logic levels, wherein the third driving potential VG3 has a duty cycle DT.

The resonant inductor LR has a first terminal and a second terminal, wherein the first terminal of the resonant inductor LR is coupled to the sixth node N6, and the second terminal of the resonant inductor LR is coupled to a seventh node N7. The resonant capacitor CR has a first terminal and a second terminal, wherein the first terminal of the resonant capacitor CR is coupled to the seventh node N7, and the second terminal of the resonant capacitor CR is coupled to an eighth node N8. The fifth transistor M5 has a control terminal (e.g., a gate), a first terminal (e.g., a source), and a second terminal (e.g., a drain), wherein the control terminal of the fifth transistor M5 is used to receive an external potential VX, the first terminal of the fifth transistor M5 is coupled to the ground potential VSS, and the second terminal of the fifth transistor M5 is coupled to a ninth node N9.

The second transformer 280 includes a second main coil 281 and a second secondary coil 282, wherein the second transformer 280 may further have a built-in second excitation inductor LM2. The second excitation inductor LM2 may be an inherent component generated when the second transformer 280 is manufactured, and is not an external independent component. The second main coil 281 and the second excitation inductor LM2 may be located on the same side of the second transformer 280 (e.g., the primary side), and the second secondary coil 282 may be located on the opposite side of the second transformer 280 (e.g., the secondary side, which may be isolated from the primary side). In detail, the second main coil 281 has a first end and a second end, wherein the first end of the second main coil 281 is coupled to the eighth node N8, and the second end of the second main coil 281 is coupled to the ninth node N9. The second excitation inductor LM2 has a first end and a second end, wherein the first end of the second excitation inductor LM2 is coupled to the eighth node N8, and the second end of the second excitation inductor LM2 is coupled to the ninth node N9. The second sub-coil 282 has a first end and a second end, wherein the first end of the second sub-coil 282 is coupled to a tenth node N10, and the second end of the second sub-coil 282 is coupled to the common node NCM. In some embodiments, the resonant inductor LR, the resonant capacitor CR, and the second magnetizing inductor LM2 may form a resonant tank of the asymmetric resonant converter 270 .

The seventh diode D7 has an anode and a cathode, wherein the anode of the seventh diode D7 is coupled to the tenth node N10, and the cathode of the seventh diode D7 is coupled to a supplementary node NA to output a supplementary potential VA. The fourth capacitor C4 has a first end and a second end, wherein the first end of the fourth capacitor C4 is coupled to the supplementary node NA, and the second end of the fourth capacitor C4 is coupled to the common node NCM. In some embodiments, the seventh diode D7 and the fourth capacitor C4 can be used as a third output stage circuit of the asymmetric resonant converter 270.

The control circuit 290 includes a microcontroller unit (MCU) 292, an error amplifier (Error Amplifier) 294, a sixth transistor M6, and a seventh transistor M7. For example, the sixth transistor M6 and the seventh transistor M7 can each be an N-type metal oxide semi-conductor field effect transistor.

The microcontroller 292 can generate a first driving potential VG1, a second driving potential VG2, a third driving potential VG3, and a fourth driving potential VG4 according to a communication potential VT and an external potential VX. The error amplifier 294 can be powered by the external potential VX and has a first input terminal, a second input terminal, and an output terminal, wherein the first input terminal of the error amplifier 294 is used to receive the output potential VOUT, the second input terminal of the error amplifier 294 is used to receive the charging potential VA, and the output terminal of the error amplifier 294 is used to output a control potential VC. For example, if the charge potential VA is exactly equal to the output potential VOUT, the error amplifier 294 will be able to output a control potential VC with a high logic level; conversely, if the charge potential VA is different from the output potential VOUT, the error amplifier 294 will be able to output a control potential VC with a low logic level.

The sixth transistor M6 has a control terminal (e.g., a gate), a first terminal (e.g., a source), and a second terminal (e.g., a drain), wherein the control terminal of the sixth transistor M6 is used to receive the control potential VC, the first terminal of the sixth transistor M6 is coupled to the output node NOUT, and the second terminal of the sixth transistor M6 is coupled to a connection node NE. The seventh transistor M7 has a control terminal (e.g., a gate), a first terminal (e.g., a source), and a second terminal (e.g., a drain), wherein the control terminal of the seventh transistor M7 is used to receive the external potential VX, the first terminal of the seventh transistor M7 is coupled to the connection node NE, and the second terminal of the seventh transistor M7 is coupled to the replenishment node NA to receive the replenishment potential VA. In some embodiments, the sixth transistor M6 and the seventh transistor M7 may be used as a connection module of the control circuit 290. For example, if both the sixth transistor M6 and the seventh transistor M7 are enabled, the asymmetric resonant converter 270 may be coupled to the second output stage circuit 260; on the contrary, for example, if either the sixth transistor M6 or the seventh transistor M7 is disabled, the asymmetric resonant converter 270 may not be coupled to the second output stage circuit 260.

FIG. 3 is a schematic diagram showing an auxiliary charger 300 according to an embodiment of the present invention. The auxiliary charger 300 is an external device and is not part of the power supply 200. In the embodiment of FIG. 3 , the auxiliary charger 300 can provide an external potential VX and includes an auxiliary microcontroller 310, wherein the auxiliary microcontroller 310 is used to generate a communication potential VT. When the auxiliary charger 300 is coupled to the power supply 200, the microcontroller 292 of the power supply 200 can obtain relevant information about the external potential VX and the maximum power of the auxiliary charger 300 by analyzing the communication potential VT. In some embodiments, the maximum power of the auxiliary charger 300 must be less than or equal to the maximum power of the power supply 200.

FIG. 4 shows a potential waveform diagram of the power supply 200 according to an embodiment of the present invention, wherein the horizontal axis represents time (s) and the vertical axis represents the potential level (V). Please refer to FIGS. 2, 3, and 4 together to understand the operating principle of the present invention. Initially, the power supply 200 does not receive any external potential VX, which can be regarded as maintained at a low logic level. At a specific time point TS, when the auxiliary charger 300 is coupled to the power supply 200, the microcontroller 292 can start to generate a third driving potential VG3 and a fourth driving potential VG4 based on the communication potential VT or (and) an external potential VX with a high logic level. In addition, because the fifth transistor M5 is enabled by the external potential VX, the asymmetric resonant converter 270 will start to provide the replenishment potential VA at the replenishment node NA.

In some embodiments, the microcontroller 292 can also adjust the output power PX of the asymmetric resonant converter 270 by changing the duty cycle DT of the third driving potential VG3. For example, if the duty cycle DT of the third driving potential VG3 increases, the output power PX of the asymmetric resonant converter 270 will increase; conversely, if the duty cycle DT of the third driving potential VG3 decreases, the output power PX of the asymmetric resonant converter 270 will decrease. In other embodiments, the duty cycle DT of the third driving potential VG3 can be between 20% and 80%, but is not limited thereto.

After a specific time point TS, the error amplifier 294 is powered by the external potential VX. If it is determined that the charging potential VA is exactly equal to the output potential VOUT, it means that the asymmetric resonant converter 270 is ready, and the error amplifier 294 will output a control potential VC with a high logic level to enable the sixth transistor M6. In addition, the seventh transistor M7 is also enabled by the external potential VX with a high logic level. Therefore, the asymmetric resonant converter 270 can be coupled in parallel with the second output stage circuit 260. Under this design, even if the corresponding system side operates in a heavy load mode and requires a stronger driving capability, the power supply 200 can also use the second output stage circuit 260 and the asymmetric resonant converter 270 to provide the output potential VOUT and the charging potential VA at the same time, thereby greatly improving the overall output stability. It must be noted that under this design, the probability of the battery element on the system side failing to charge normally will be effectively reduced.

The present invention proposes a novel power supply. According to actual measurement results, the power supply with the above design can significantly improve the overall output stability, so it is very suitable for application in various types of devices.

It is worth noting that the potential, current, resistance, inductance, capacitance, and other component parameters described above 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 states shown in Figures 1-4. The present invention may only include any one or more features of any one or more embodiments of Figures 1-4. In other words, not all of the features shown in the diagrams need to be implemented in the power supply of the present invention at the same time. Although the embodiments of the present invention use metal oxide semi-conductor field effect transistors as an example, the present invention is not limited to this. People skilled in the art can use other types of transistors, such as junction field effect transistors, or fin field effect transistors, etc., without affecting the effects of the present invention.

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, and are only used to mark and distinguish two different components with the same name.

Although the present invention is disclosed as above with the preferred embodiments, it is not intended to limit the scope of the present invention. Anyone skilled in the art can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the attached patent application.

100,200: Power supply 110,210: Bridge rectifier 120,220: First power switch 130,230: First output stage circuit 140,240: First transformer 141,241: First main coil 142,242: First secondary coil 150,250: Second power switch 160,260: Second output stage circuit 170,270: Asymmetric resonant converter 190,290: Control circuit 280: Second transformer 281: Second main coil 282: Second secondary coil 292: Microcontroller 294: Error amplifier 300: Auxiliary charger 310: auxiliary microcontroller C1: first capacitor C2: second capacitor C3: third capacitor C4: fourth capacitor CR: resonant capacitor D1: first diode D2: second diode D3: third diode D4: fourth diode D5: fifth diode D6: sixth diode D7: seventh diode DT: duty cycle LM1: first magnetizing inductor LM2: second magnetizing inductor LR: resonant inductor LU: boost inductor M1: first transistor M2: second transistor M3: third transistor M4: fourth transistor M5: fifth transistor M6: sixth transistor M7: seventh transistor N1: first node N2: second node N3: Third node N4: Fourth node N5: Fifth node N6: Sixth node N7: Seventh node N8: Eighth node N9: Ninth node N10: Tenth node NA: Supplementary node NCM: Common node NE: Connection node NIN1: First input node NIN2: Second input node NOUT: Output node PX: Output power TS: Specific time point VA: Supplementary potential VC: Control potential VE: Intermediate potential VG1: First drive potential VG2: Second drive potential VG3: Third drive potential VG4: Fourth drive potential VIN1: First input potential VIN2: Second input potential VOUT: Output potential VR: Rectification potential VSS: Ground potential VT: Communication potential VX: External potential

FIG. 1 is a schematic diagram showing a power supply according to an embodiment of the present invention. FIG. 2 is a circuit diagram showing a power supply according to an embodiment of the present invention. FIG. 3 is a schematic diagram showing an auxiliary charger according to an embodiment of the present invention. FIG. 4 is a potential waveform diagram showing a power supply according to an embodiment of the present invention.

100: Power supply

110: Bridge rectifier

120: First power switch

130: First output stage circuit

140: First transformer

141: First main coil

142: First coil

150: Second power switch

160: Second output stage circuit

170: Asymmetric resonant converter

190: Control circuit

C1: First capacitor

LU: Boost Inductor

VA: Charge potential

VE: Middle potential

VG1: first driving potential

VG2: Second driving potential

VG3: The third driving potential

VG4: Fourth drive potential

VIN1: first input potential

VIN2: Second input potential

VOUT: output voltage

VR: Rectification potential

VSS: ground potential

VT: Communication potential

VX: external potential

Claims (10)

A power supply with high output stability, comprising: a bridge rectifier, generating a rectified potential according to a first input potential and a second input potential; a first capacitor, storing the rectified potential; a boost inductor, receiving the rectified potential; a first power switch, selectively coupling the boost inductor to a ground potential according to a first drive potential; a first output stage circuit, coupled to the boost inductor, and generating an intermediate potential; a first transformer, comprising a first main coil and a first secondary coil, wherein the first main coil is used to receive the intermediate potential; a second power switch, selectively coupling the first main coil to the ground potential according to a second drive potential; A second output stage circuit coupled to the first secondary coil and generating an output potential; An asymmetric resonant converter providing a supplementary potential according to the rectified potential, a third drive potential, a fourth drive potential, and an external potential; and A control circuit generating the first drive potential, the second drive potential, the third drive potential, and the fourth drive potential according to a communication potential; The control circuit selectively couples the asymmetric resonant converter to the second output stage circuit according to the external potential. A power supply as described in claim 1, wherein the bridge rectifier comprises: 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 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 cathode of the second diode 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; wherein the first capacitor has a first end and a second end, the first end of the first capacitor is coupled to the first node to store the rectified potential, and the second end of the first capacitor is coupled to the ground potential; The boost 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. A power supply as described in claim 2, wherein the first output stage circuit comprises: 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 second capacitor having a first end and a second end, wherein the first end of the second capacitor is coupled to the third node, and the second end of the second capacitor is coupled to the ground potential. A power supply as described in claim 3, wherein the first transformer further has a built-in first excitation inductor, the first main coil having a first end and a second end, the first end of the first main coil being coupled to the third node to receive the intermediate potential, the second end of the first main coil being coupled to a fourth node, the first excitation inductor having a first end and a second end, the first end of the first excitation inductor being coupled to the third node, the second end of the first excitation inductor being coupled to the fourth node, the first secondary coil having a first end and a second end, the first end of the first secondary coil being coupled to a fifth node, and the second end of the first secondary coil being coupled to a common node. A power supply as described in claim 4, wherein the first power switch comprises: A first transistor having a control terminal, a first terminal, and a second terminal, wherein the control terminal of the first transistor is used to receive the first driving 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; Wherein the second power switch comprises: 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 driving potential, the first terminal of the second transistor is coupled to the ground potential, and the second terminal of the second transistor is coupled to the fourth node. A power supply as described in claim 4, wherein the second output stage circuit comprises: 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 third capacitor having a first end and a second end, wherein the first end of the third capacitor is coupled to the output node, and the second end of the third capacitor is coupled to the common node. A power supply as described in claim 1, wherein the asymmetric resonant converter comprises: a third transistor having a control terminal, a first terminal, and a second terminal, wherein the control terminal of the third transistor is used to receive the third driving potential, the first terminal of the third transistor is coupled to a sixth node, and the second terminal of the third transistor is used to receive the rectified potential; a fourth transistor having a control terminal, a first terminal, and a second terminal, wherein the control terminal of the fourth transistor is used to receive the fourth driving potential, the first terminal of the fourth transistor is coupled to the ground potential, and the second terminal of the fourth transistor is coupled to the sixth node; A resonant inductor having a first end and a second end, wherein the first end of the resonant inductor is coupled to the sixth node, and the second end of the resonant inductor is coupled to a seventh node; A resonant capacitor having a first end and a second end, wherein the first end of the resonant capacitor is coupled to the seventh node, and the second end of the resonant capacitor is coupled to an eighth node; and A fifth transistor having a control end, a first end, and a second end, wherein the control end of the fifth transistor is used to receive the external potential, the first end of the fifth transistor is coupled to the ground potential, and the second end of the fifth transistor is coupled to a ninth node. The power supply as described in claim 7, wherein the asymmetric resonant converter further comprises: A second transformer, comprising a second main coil and a second secondary coil, wherein the second transformer further has a built-in second excitation inductor, the second main coil having a first end and a second end, the first end of the second main coil being coupled to the eighth node, the second end of the second main coil being coupled to the ninth node, the second excitation inductor having a first end and a second end, the first end of the second excitation inductor being coupled to the eighth node, the second end of the second excitation inductor being coupled to the ninth node, the second secondary coil having a first end and a second end, the first end of the second secondary coil being coupled to a tenth node, and the second end of the second secondary coil being coupled to a common node; A seventh diode having an anode and a cathode, wherein the anode of the seventh diode is coupled to the tenth node, and the cathode of the seventh diode is coupled to a supplement node to output the supplement potential; and A fourth capacitor having a first end and a second end, wherein the first end of the fourth capacitor is coupled to the supplement node, and the second end of the fourth capacitor is coupled to the common node. A power supply as described in claim 1, wherein the control circuit includes: a microcontroller, which generates the first drive potential, the second drive potential, the third drive potential, and the fourth drive potential according to the communication potential and the external potential; and an error amplifier, which is powered by the external potential and has a first input terminal, a second input terminal, and an output terminal, wherein the first input terminal of the error amplifier is used to receive the output potential, the second input terminal of the error amplifier is used to receive the supplementary potential, and the output terminal of the error amplifier is used to output a control potential. A power supply as described in claim 9, wherein the control circuit further comprises: a sixth transistor having a control terminal, a first terminal, and a second terminal, wherein the control terminal of the sixth transistor is used to receive the control potential, the first terminal of the sixth transistor is coupled to an output node, and the second terminal of the sixth transistor is coupled to a connection node; and a seventh transistor having a control terminal, a first terminal, and a second terminal, wherein the control terminal of the seventh transistor is used to receive the external potential, the first terminal of the seventh transistor is coupled to the connection node, and the second terminal of the seventh transistor is coupled to a supplement node to receive the supplement potential.

Images