Power supply device for noise suppression

Abstract

A power supply device for noise suppression includes a bridge rectifier, a tunable filter circuit, a boost inductor, a power switch element, a first output stage circuit, a switch circuit, a transformer, a resonant capacitor, a second output stage circuit, a third output stage circuit, and a detection and control circuit. The tunable filter circuit is coupled to the bridge rectifier. The first output stage circuit generates a middle voltage. The second output stage circuit generates an output voltage. The third output stage circuit generates an auxiliary voltage. The detection and control circuit can enable or disable the tunable filter circuit according to the middle voltage, the output voltage, and the auxiliary voltage.

Description

[Technical Field]

[0001] This invention relates to a power supply, and more particularly to a power supply capable of suppressing noise. [Previous Technology]

[0002] Power supplies are an indispensable component in the notebook computer industry. However, if the noise associated with the power supply is too high, it can easily cause a decline in the overall operating performance of the notebook computer. In view of this, it is necessary to propose a completely new solution to overcome the difficulties faced by previous technologies. [Summary of the Invention]

[0003] In a preferred embodiment, the present invention provides a noise-suppressing power supply, comprising: a bridge rectifier that generates a rectification potential based on a first input potential and a second input potential; an adjustable filter circuit coupled to the bridge rectifier; a boost inductor that receives the rectification potential; a power switch that selectively couples the boost inductor to a ground potential based on a first drive potential; a first output stage circuit coupled to the boost inductor and generating an intermediate potential; a switching circuit that generates a switching potential based on the intermediate potential, a second drive potential, and a third drive potential; and a transformer including a main coil and a first secondary coil. The transformer comprises a primary coil, a second secondary coil, and an auxiliary coil, wherein the transformer has a built-in leakage inductor and a magnetizing inductor, and the primary coil receives the switching potential through the leakage inductor; a resonant capacitor coupled to the magnetizing inductor; a second output stage circuit coupled to the primary and secondary coils and generating an output potential; a third output stage circuit coupled to the auxiliary coil and generating an auxiliary potential; and a detection and control circuit generating the first drive potential, the second drive potential, and the third drive potential; wherein the detection and control circuit enables or disables the adjustable filter circuit based on the intermediate potential, the output potential, and the auxiliary potential.

[0004] In some embodiments, the bridge rectifier includes: a first diode having an anode and a cathode, wherein the anode system of the first diode is coupled to a first input node to receive the first input potential, and the cathode system 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 system of the second diode is coupled to a second input node to receive the second input potential, and the cathode system of the second diode is coupled to the first node; and a third diode having an anode and a cathode. 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 has 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 inductor has a first terminal and a second terminal, the first terminal of the boost inductor is coupled to the first node to receive the rectified potential, and the second terminal of the boost inductor is coupled to a second node.

[0005] In some embodiments, the adjustable filter 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 ground potential, and the second terminal of the first resistor is coupled to a third node; a first capacitor having a first terminal and a second terminal, wherein the first terminal of the first capacitor is coupled to the ground potential, and the second terminal of the first capacitor is coupled to the third node; and a first transistor having a control terminal and a first terminal, for... The first transistor has a control terminal, a first terminal, and a second terminal, wherein the control terminal of the first transistor is used to receive a first control potential, the first terminal of the first transistor is coupled to a fourth node, and the second terminal of the first transistor is coupled to the third node; and a second transistor has a control terminal, a first terminal, and a second terminal, wherein the control terminal of the second transistor is used to receive a second control potential, the first terminal of the second transistor is coupled to a ground potential, and the second terminal of the second transistor is coupled to the fourth node.

[0006] In some embodiments, the power switch 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 first drive potential, the first terminal of the third transistor is coupled to the ground potential, and the second terminal of the third transistor is coupled to the second node.

[0007] 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 fifth node to output the intermediate potential; and a second capacitor having a first terminal and a second terminal, wherein the first terminal of the second capacitor is coupled to the fifth node, and the second terminal of the second capacitor is coupled to the ground potential.

[0008] In some embodiments, the switching circuit includes: 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 second driving potential, the first terminal of the fourth transistor is coupled to a sixth node to output the switching potential, and the second terminal of the fourth transistor is coupled to the fifth node to receive the intermediate potential; and a fifth transistor having a control terminal, a first terminal, and a second terminal, wherein the control terminal of the fifth transistor is used to receive the third driving potential, the first terminal of the fifth transistor is coupled to the ground potential, and the second terminal of the fifth transistor is coupled to the sixth node.

[0009] In some embodiments, the leakage inductor has a first terminal and a second terminal, the first terminal of the leakage inductor being coupled to the sixth node to receive the switching potential, and the second terminal of the leakage inductor being coupled to a seventh node. The main coil has a first terminal and a second terminal, the first terminal of the main coil being coupled to the seventh node, and the second terminal of the main coil being coupled to an eighth node. The magnetizing inductor has a first terminal and a second terminal, the first terminal of the magnetizing inductor being coupled to the seventh node, and the second terminal of the magnetizing inductor being coupled to the eighth node. The resonant capacitor has a first terminal and a second terminal. The first end of the device is coupled to the eighth node, the second end of the resonant capacitor is coupled to the ground potential, the first secondary coil has a first end and a second end, the first end of the first secondary coil is coupled to a ninth node, the second end of the first secondary coil is coupled to a common node, the second secondary coil has a first end and a second end, the first end of the second secondary coil is coupled to the common node, the second end of the second secondary coil is coupled to a tenth node, the auxiliary coil has a first end and a second end, the first end of the auxiliary coil is coupled to an eleventh node, and the second end of the auxiliary coil is coupled to the ground potential.

[0010] 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 ninth node, and the cathode of the sixth diode is coupled to an output node to output the output potential; 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 the output node; and a third capacitor having a first terminal and a second terminal, wherein the first terminal of the third capacitor is coupled to the output node, and the second terminal of the third capacitor is coupled to the common node.

[0011] In some embodiments, the third output stage circuit includes: an eighth diode having an anode and a cathode, wherein the anode of the eighth diode is coupled to the eleventh node and the cathode of the eighth diode is coupled to a twelfth node to output the auxiliary potential; and a fourth capacitor having a first terminal and a second terminal, wherein the first terminal of the fourth capacitor is coupled to the twelfth node and the second terminal of the fourth capacitor is coupled to the ground potential.

[0012] In some embodiments, the detection and control circuit includes: a microcontroller that generates the first driving potential, the second driving potential, and the third driving potential; a second resistor having a first terminal and a second terminal, wherein the first terminal of the second resistor is coupled to the fifth node to receive the intermediate potential, and the second terminal of the second resistor is coupled to a thirteenth node; a third resistor having a first terminal and a second terminal, wherein the first terminal of the third resistor is coupled to the thirteenth node, and the second terminal of the third resistor is coupled to the ground potential; a linear optocoupler including a light-emitting diode and a bipolar 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... At the thirteenth node, the cathode system of the light-emitting diode is coupled to the ground potential; the bipolar junction transistor has a collector and an emitter, the collector system of the bipolar junction transistor is used to output a feedback potential, and the emitter system of the bipolar junction transistor is coupled to a fourteenth node; a fifth capacitor has a first terminal and a second terminal, wherein the first terminal of the fifth capacitor is coupled to the fourteenth node, and the second terminal of the fifth capacitor is coupled to the ground potential; a first amplifier amplifies the feedback potential by a first gain factor to generate the first control potential; and a second amplifier amplifies the auxiliary potential by a second gain factor to generate the second control potential; wherein both the first amplifier and the second amplifier are powered by the output potential.

Implementation Method

[0013] In order to make the objectives, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below in conjunction with the accompanying drawings for detailed explanation.

[0014] Certain terms are used in the specification and 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 claims do not distinguish components by differences in name, but by differences in function. The terms "comprising" and "including" used throughout the specification and claims are open-ended and should be interpreted as "including but not limited to". The term "generally" means that within an acceptable margin of error, those skilled in the art can solve the technical problem and achieve the basic technical effect within a certain margin of error. Furthermore, the term "coupled" in this specification includes any direct and indirect electrical connection means. Therefore, if a first device is described as 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 connection means.

[0015] Figure 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 Figure 1, the power supply 100 includes: a bridge rectifier 110, a boost inductor 100, an adjustable filter circuit 120, a power switch 130, a first output stage circuit 140, a switching circuit 150, a transformer 160, a resonant capacitor CR, a second output stage circuit 170, a third output stage circuit 180, and a detection and control circuit 190. It should be noted that, although not shown in Figure 1, the power supply 100 may also include other components, such as: a voltage regulator and / or a negative feedback circuit.

[0016] The bridge rectifier 110 can generate a rectified potential VR based on a first input potential VIN1 and a second input potential VIN2, wherein an AC voltage with arbitrary frequency and 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 50Hz or 60Hz, and the root mean square value of the AC voltage can be approximately between 90V and 264V, but is not limited thereto. An adjustable filter circuit 120 is coupled to the bridge rectifier 110. A boost inductor LU can receive the rectified potential VR. The power switch 130 can selectively couple the boost inductor LU to a ground potential VSS (e.g., 0V) based on a first drive potential VG1. For example, if the first drive potential VG1 has a high logic level (i.e., logic "1"), the power switch 130 can couple the boost inductor LU to the ground potential VSS (i.e., the power switch 130 can be approximated as a short-circuit path); conversely, if the first drive potential VG1 has a low logic level (i.e., logic "0"), the power switch 130 will not couple the boost inductor LU to the ground potential VSS (i.e., the power switch 130 can be approximated as an open-circuit path).

[0017] The first output stage circuit 140 is coupled to the boost inductor LU and can generate an intermediate potential VE. The switching circuit 150 can generate a switching potential VW based on the intermediate potential VE, a second drive potential VG2, and a third drive potential VG3. The transformer 160 includes a main coil 161, a first secondary coil 162, a second secondary coil 163, and an auxiliary coil 164. The transformer 160 may also have a built-in leakage inductor LR and a magnetizing inductor LM, wherein the leakage inductor LR, the magnetizing inductor LM, the main coil 161, and the auxiliary coil 164 can all be located on the same side of the transformer 160, while the first secondary coil 162 and the second secondary coil 163 can both be located on the opposite side of the transformer 160. The main coil 161 can receive the switching potential VW through the leakage inductor LR, while the first secondary coil 162, the second secondary coil 163, and the auxiliary coil 164 can operate in response to the switching potential VW. The resonant capacitor CR is coupled to the magnetizing inductor LM. For example, the leakage inductor LR, the magnetizing inductor LM, and the resonant capacitor CR together form a resonant tank in the power supply 100. The second output stage circuit 170 is coupled to the first secondary coil 162 and the second secondary coil 163, and can generate an output potential VOUT. 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 to this. In addition, the third output stage circuit 180 is coupled to the auxiliary coil 164 and can generate an auxiliary potential VA. It must be understood that both the output potential VOUT and the auxiliary potential VA are related to the switching potential VW.

[0018] The detection and control circuit 190 can generate a first drive potential VG1, a second drive potential VG2, and a third drive potential VG3. Furthermore, the detection and control circuit 190 can enable or disable the adjustable filter circuit 120 based on the intermediate potential VE, the output potential VOUT, and the auxiliary potential VA. Under this design, since the adjustable filter circuit 120 is only selectively utilized by the power supply 100, it can prevent accidental damage to the adjustable filter circuit 120 caused by the startup energy of the power supply 100. According to actual measurement results, the power supply 100 proposed in this invention can effectively maintain the reliability of the adjustable filter circuit 120, thereby significantly suppressing the noise associated with the first input potential VIN1 and the second input potential VIN2.

[0019] The following embodiments will describe the detailed structure and operation of the power supply 100. It must be understood that these figures and descriptions are merely examples and are not intended to limit the scope of the invention.

[0020] Figure 2 shows a circuit diagram of a power supply 200 according to an embodiment of the present invention. In the embodiment of Figure 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, an adjustable filter circuit 220, a power switch 230, a first output stage circuit 240, a switching circuit 250, a transformer 260, a resonant capacitor CR, a second output stage circuit 270, a third output stage circuit 280, and a detection and 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 respectively from an external input power source (not shown), while the output node NOUT of the power supply 200 can be used to output an output potential VOUT to an external device, such as a system terminal (not shown).

[0021] 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 a 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 a second input node NIN2, and the cathode of the second diode D2 is coupled to a 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 system of the fourth diode D4 is coupled to ground potential VSS, and the cathode system of the fourth diode D4 is coupled to the second input node NIN2.

[0022] The boost inductor LU has a first terminal and a second terminal, wherein the first terminal of the boost inductor LU is coupled to a first node N1 to receive a rectified potential VR, and the second terminal of the boost inductor LU is coupled to a second node N2.

[0023] The adjustable filter circuit 220 includes: a first transistor M1, a second transistor M2, a first capacitor C1, and a first resistor R1. For example, the first transistor M1 and the second transistor M2 can each be an N-type metal-oxide-semiconductor field-effect transistor (NMOSFET). The first resistor R1 has a first terminal and a second terminal, wherein the first terminal of the first resistor R1 is coupled to ground potential VSS, and the second terminal of the first resistor R1 is coupled to a third node N3. The first capacitor C1 has a first terminal and a second terminal, wherein the first terminal of the first capacitor C1 is coupled to ground potential VSS, and the second terminal of the first capacitor C1 is coupled to the third node N3. In some embodiments, the first terminal of the first resistor R1 and the first terminal of the first capacitor C1 can both be coupled to the anode of the third diode D3 and the anode of the fourth diode D4, wherein the first resistor R1 and the first capacitor C1 can together serve as an RC filter in the bridge rectifier 210. 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 can be used to receive a first control potential VC1, the first terminal of the first transistor M1 is coupled to a fourth node N4, and the second terminal of the first transistor M1 is coupled to a third node N3. The second transistor M2 has a control terminal (e.g., a gate), a first terminal (e.g., a source), and a second terminal (e.g., a drain). The control terminal of the second transistor M2 can be used to receive a second control potential VC2. The first terminal of the second transistor M2 is coupled to a ground potential VGS, and the second terminal of the second transistor M2 is coupled to a fourth node N4. It should be noted that the ground potential VGS can be considered as another ground potential, which may be the same as or different from the aforementioned ground potential VSS. For example, the ground potential VGS may be provided by a system grounding element that can absorb a large amount of charge or be directly coupled to the ground, but is not limited to this. In some embodiments, if both the first control potential VC1 and the second control potential VC2 have high logic levels, the adjustable filter circuit 220 will be enabled. In other embodiments, if both the first control potential VC1 and the second control potential VC2 have low logic levels, the adjustable filter circuit 220 will be disabled.

[0024] The power switch 230 includes a third transistor M3. For example, the third transistor M3 may be an N-type metal-oxide-semiconductor 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 can be used to receive a first drive potential VG1, the first terminal of the third transistor M3 is coupled to a ground potential VSS, and the second terminal of the third transistor M3 is coupled to a second node N2.

[0025] The first output stage circuit 240 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 a second node N2, and the cathode of the fifth diode D5 is coupled to a fifth node N5 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 fifth node N5, and the second terminal of the second capacitor C2 is coupled to ground potential VSS.

[0026] The switching circuit 250 includes a fourth transistor M4 and a fifth transistor M5. For example, the fourth transistor M4 and the fifth transistor M5 may each be an N-type metal-oxide-semiconductor field-effect transistor. 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 can be used to receive a second drive potential VG2, the first terminal of the fourth transistor M4 is coupled to a sixth node N6 to output a switching potential VW, and the second terminal of the fourth transistor M4 is coupled to a fifth node N5 to receive an intermediate potential VE. 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). The control terminal of the fifth transistor M5 can be used to receive a third driving potential VG3. 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 the sixth node N6.

[0027] Transformer 260 includes a main coil 261, a first secondary coil 262, a second secondary coil 263, and an auxiliary coil 264. Transformer 260 further integrates a leakage inductor LR and a magnetizing inductor LM. The leakage inductor LR and magnetizing inductor LM are inherent components generated during the manufacture of transformer 260 and are not external independent components. The leakage inductor LR, magnetizing inductor LM, main coil 261, and auxiliary coil 264 can all be located on the same side of transformer 260 (e.g., the primary side), while the first secondary coil 262 and second secondary coil 263 can both be located on the opposite side of transformer 260 (e.g., the secondary side, which can be isolated from the primary side). The leakage inductor LR has a first terminal and a second terminal, wherein the first terminal of the leakage inductor LR is coupled to a sixth node N6 to receive a switching potential VW, and the second terminal of the leakage inductor LR is coupled to a seventh node N7. 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 seventh node N7, and the second end of the main coil 261 is coupled to the eighth node N8. The magnetizing inductor LM has a first end and a second end, wherein the first end of the magnetizing inductor LM is coupled to the seventh node N7, and the second end of the magnetizing inductor LM is coupled to the eighth node N8. The resonant capacitor CR has a first end and a second end, wherein the first end of the resonant capacitor CR is coupled to the eighth node N8, and the second end of the resonant capacitor CR is coupled to ground potential VSS. For example, the leakage inductor LR, the magnetizing inductor LM, and the resonant capacitor CR can together form a resonant slot in the power supply 200. The first secondary coil 262 has a first end and a second end, wherein the first end of the first secondary coil 262 is coupled to the ninth node N9, and the second end of the first secondary coil 262 is coupled to a common node NCM. For example, the common node NCM can provide a common potential, which can be considered as another ground potential and may be the same as or different from the aforementioned ground potential VSS. The second secondary coil 263 has a first end and a second end, wherein the first end of the second secondary coil 263 is coupled to the common node NCM, and the second end of the second secondary coil 263 is coupled to a tenth node N10. The auxiliary coil 264 has a first end and a second end, wherein the first end of the auxiliary coil 264 is coupled to an eleventh node N11, and the second end of the auxiliary coil 264 is coupled to the earth potential VGS.

[0028] The second output stage circuit 270 includes a sixth diode D6, a seventh diode D7, 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 ninth node N9, and the cathode of the sixth diode D6 is coupled to the output node NOUT. 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 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.

[0029] The third output stage circuit 280 includes an eighth diode D8 and a fourth capacitor C4. The eighth diode D8 has an anode and a cathode, wherein the anode of the eighth diode D8 is coupled to an eleventh node N11, and the cathode of the eighth diode D8 is coupled to a twelfth node N12 to output an auxiliary potential VA. The fourth capacitor C4 has a first terminal and a second terminal, wherein the first terminal of the fourth capacitor C4 is coupled to the twelfth node N12, and the second terminal of the fourth capacitor C4 is coupled to ground potential VGS.

[0030] The detection and control circuit 290 includes: a microcontroller unit (MCU) 292, a linear optical coupler 294, a first amplifier 296, a second amplifier 298, a fifth capacitor C5, a second resistor R2, and a third resistor R3.

[0031] The microcontroller 292 can generate a first drive potential VG1, a second drive potential VG2, and a third drive potential VG3. For example, the first drive potential VG1 can be a pulse width modulation (PWM) potential, which 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 operation phase. In addition, the second drive potential VG2 and the third drive potential VG3 can have complementary logic levels.

[0032] 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 fifth node N5 to receive the intermediate potential VE, and the second terminal of the second resistor R2 is coupled to the thirteenth node N13. The third resistor R3 has a first terminal and a second terminal, wherein the first terminal of the third resistor R3 is coupled to the thirteenth node N13, and the second terminal of the third resistor R3 is coupled to the ground potential VSS. Because the second resistor R2 and the third resistor R3 can together form a voltage divider, the potential at the thirteenth node N13 is approximately proportional to the intermediate potential VE.

[0033] The linear optocoupler 294 includes a light-emitting diode (LED) DL and a bipolar junction transistor (BJT) Q6 (e.g., NPN type). The LED DL has an anode and a cathode, wherein the anode of the LED DL is coupled to a thirteenth node N13, and the cathode of the LED DL is coupled to ground potential VSS. The BJT Q6 has a collector and an emitter, wherein the collector of the BJT Q6 is used to output a feedback potential VF, and the emitter of the BJT Q6 is coupled to a fourteenth node N14. Additionally, a fifth capacitor C5 has a first terminal and a second terminal, wherein the first terminal of the fifth capacitor C5 is coupled to the fourteenth node N14, and the second terminal of the fifth capacitor C5 is coupled to ground potential VGS.

[0034] Both the first amplifier 296 and the second amplifier 298 can be powered by the output potential VOUT. The first amplifier 296 can amplify the feedback potential VF by a first gain factor K1 to generate a first control potential VC1. The second amplifier 298 can amplify the auxiliary potential VA by a second gain factor K2 to generate a second control potential VC2. For example, the first gain factor K1 can be between 10 and 15 times, and the second gain factor K2 can be between 3 and 5 times, but is not limited thereto. In some embodiments, the first amplifier 296 and the second amplifier 298 can operate according to the following equations (1) and (2):

[0035] ………………………………………(1)

[0036] ………………………………………(2) Where “VC1” represents the level of the first control potential VC1, “VC2” represents the level of the second control potential VC2, “K1” represents the value of the first gain ratio K1, “K2” represents the value of the second gain ratio K2, “VF” represents the level of the feedback potential VF, and “VA” represents the level of the auxiliary potential VA.

[0037] In some embodiments, the operating principle of the power supply 200 may be as follows. Initially, a larger startup energy enters the power supply 200, but the levels of the first control potential VC1 and the second control potential VC2 are relatively low, causing the adjustable filter circuit 220 to be temporarily disabled. Next, after an initialization period, the intermediate potential VE, output potential VOUT, and auxiliary potential VA of the power supply 200 are fully established and reach their respective required levels. At this time, the levels of the first control potential VC1 and the second control potential VC2 are high enough to enable the adjustable filter circuit 220. In other words, the adjustable filter circuit 220 is initially disabled, so it is not easily damaged by the startup energy of the power supply 200; then, when the power supply 200 enters a stable state, the adjustable filter circuit 220 is normally enabled, thereby eliminating the related noise of the first input potential VIN1 and the second input potential VIN2. Under the design proposed in this invention, the probability of the adjustable filter circuit 220 failing due to the startup energy of the power supply 200 can be greatly reduced.

[0038] This invention proposes a novel power supply. According to actual measurement results, the relevant noise of the power supply using the aforementioned design can be effectively suppressed, making it very suitable for application in a wide variety of devices.

[0039] It is worth noting that the potential, current, resistance, inductance, capacitance, and other component parameters mentioned above are not limiting conditions of this invention. Designers can adjust these settings according to different needs. The power supply of this invention is not limited to the state illustrated in Figures 1-2. This invention may include only any one or more features of any one or more embodiments of Figures 1-2. In other words, not all features illustrated need to be implemented simultaneously in the power supply of this invention. Although the embodiments of this invention use metal-oxide-semiconductor field-effect transistors as examples, this invention is not limited to this. Those skilled in the art can use other types of transistors, such as junction field-effect transistors or fin field-effect transistors, without affecting the effect of this invention.

[0040] The ordinal numbers in this specification and the claims, such as "first", "second", "third", etc., have no sequential relationship with each other and are only used to distinguish two different elements with the same name.

[0041] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the scope of the present invention. Anyone skilled in the art can make some modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims. [Simplified Explanation of the Diagram]

[0042] Figure 1 shows a schematic diagram of a power supply according to an embodiment of the present invention. Figure 2 shows a circuit diagram of a power supply according to an embodiment of the present invention.

Claims

1. A noise-suppressing power supply, comprising: A bridge rectifier generates a rectified potential based on a first input potential and a second input potential; an adjustable filter circuit is coupled to the bridge rectifier; a boost inductor receives the rectified potential; a power switch selectively couples the boost inductor to a ground potential based on a first drive potential; a first output stage circuit is coupled to the boost inductor and generates an intermediate potential; a switching circuit generates a switching potential based on the intermediate potential, a second drive potential, and a third drive potential; a transformer including a main coil, a first secondary coil, a second secondary coil, and an auxiliary coil, wherein the transformer has a built-in leakage inductor and a magnetizing inductor, and the main coil receives the switching potential through the leakage inductor; a resonant capacitor is coupled to the magnetizing inductor; a second output stage circuit is coupled to the first secondary coil and the second secondary coil and generates an output potential; A third output stage circuit is coupled to the auxiliary coil and generates an auxiliary potential; and a detection and control circuit generates the first drive potential, the second drive potential, and the third drive potential; wherein the detection and control circuit enables or disables the adjustable filter circuit based on the intermediate potential, the output potential, and the auxiliary potential.

2. The power supply as claimed in claim 1, wherein the bridge rectifier comprises: A first diode having an anode and a cathode, wherein the anode system of the first diode is coupled to a first input node to receive the first input potential, and the cathode system 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 system of the second diode is coupled to a second input node to receive the second input potential, and the cathode system of the second diode is coupled to the first node; a third diode having an anode and a cathode, wherein the anode system of the third diode is coupled to the ground potential, and the cathode system 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 inductor has a first terminal and a second terminal, the first terminal of the boost inductor is coupled to the first node to receive the rectified potential, and the second terminal of the boost inductor is coupled to a second node.

3. The power supply as described in claim 2, wherein the adjustable filter 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 ground potential, and the second terminal of the first resistor is coupled to a third node; a first capacitor having a first terminal and a second terminal, wherein the first terminal of the first capacitor is coupled to the ground potential, and the second terminal of the first capacitor is coupled to the third node; 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 a first control potential, the first terminal of the first transistor is coupled to a fourth node, and the second terminal of the first transistor is coupled to the third node; and 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 a second control potential, the first terminal of the second transistor is coupled to a ground potential, and the second terminal of the second transistor is coupled to the fourth node.

4. The power supply as described in claim 2, wherein the power switch comprises: A third transistor has a control terminal, a first terminal, and a second terminal, wherein the control terminal of the third transistor is used to receive the first driving potential, the first terminal of the third transistor is coupled to the ground potential, and the second terminal of the third transistor is coupled to the second node.

5. The power supply as claimed in claim 3, wherein the first output stage circuitry 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 fifth node to output the intermediate potential; and a second capacitor having a first terminal and a second terminal, wherein the first terminal of the second capacitor is coupled to the fifth node, and the second terminal of the second capacitor is coupled to the ground potential.

6. The power supply as described in claim 5, wherein the switching circuit includes: A fourth transistor has a control terminal, a first terminal, and a second terminal, wherein the control terminal of the fourth transistor is used to receive the second driving potential, the first terminal of the fourth transistor is coupled to a sixth node to output the switching potential, and the second terminal of the fourth transistor is coupled to a fifth node to receive the intermediate potential; and a fifth transistor has a control terminal, a first terminal, and a second terminal, wherein the control terminal of the fifth transistor is used to receive the third driving potential, the first terminal of the fifth transistor is coupled to the ground potential, and the second terminal of the fifth transistor is coupled to the sixth node.

7. The power supply as claimed in claim 6, wherein the leakage inductor has a first terminal and a second terminal, the first terminal of the leakage inductor being coupled to the sixth node to receive the switching potential, the second terminal of the leakage inductor being coupled to a seventh node, the main coil having a first terminal and a second terminal, the first terminal of the main coil being coupled to the seventh node, the second terminal of the main coil being coupled to an eighth node, the magnetizing inductor having a first terminal and a second terminal, the first terminal of the magnetizing inductor being coupled to the seventh node, the second terminal of the magnetizing inductor being coupled to the eighth node, the resonant capacitor having a first terminal and a second terminal, the resonant... The first end of the capacitor is coupled to the eighth node, the second end of the resonant capacitor is coupled to the ground potential, the first secondary coil has a first end and a second end, the first end of the first secondary coil is coupled to a ninth node, the second end of the first secondary coil is coupled to a common node, the second secondary coil has a first end and a second end, the first end of the second secondary coil is coupled to the common node, the second end of the second secondary coil is coupled to a tenth node, the auxiliary coil has a first end and a second end, the first end of the auxiliary coil is coupled to an eleventh node, and the second end of the auxiliary coil is coupled to the ground potential.

8. The power supply as claimed in claim 7, wherein the second output stage circuitry includes: A sixth diode having an anode and a cathode, wherein the anode of the sixth diode is coupled to the ninth node, and the cathode of the sixth diode is coupled to an output node to output the output potential; 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 the output node; and a third capacitor having a first terminal and a second terminal, wherein the first terminal of the third capacitor is coupled to the output node, and the second terminal of the third capacitor is coupled to the common node.

9. The power supply as claimed in claim 7, wherein the third output stage circuitry includes: An eighth diode having an anode and a cathode, wherein the anode of the eighth diode is coupled to the eleventh node and the cathode of the eighth diode is coupled to a twelfth node to output the auxiliary potential; and a fourth capacitor having a first terminal and a second terminal, wherein the first terminal of the fourth capacitor is coupled to the twelfth node and the second terminal of the fourth capacitor is coupled to the ground potential.

10. The power supply as described in claim 5, wherein the detection and control circuitry includes: A microcontroller that generates the first drive potential, the second drive potential, and the third drive potential; a second resistor having a first terminal and a second terminal, wherein the first terminal of the second resistor is coupled to the fifth node to receive the intermediate potential, and the second terminal of the second resistor is coupled to a thirteenth node; a third resistor having a first terminal and a second terminal, wherein the first terminal of the third resistor is coupled to the thirteenth node, and the second terminal of the third resistor is coupled to the ground potential; A linear optocoupler includes a light-emitting diode (LED) and a bipolar junction transistor (BJT), wherein the LED has an anode and a cathode, the anode of the LED is coupled to the thirteenth node, the cathode of the LED is coupled to the ground potential, the BJT has a collector and an emitter, the collector of the BJT is used to output a feedback potential, and the emitter of the BJT is coupled to the fourteenth node; a fifth capacitor has a first terminal and a second terminal, wherein the first terminal of the fifth capacitor is coupled to the fourteenth node, and the second terminal of the fifth capacitor is coupled to the ground potential; a first amplifier amplifies the feedback potential by a first gain factor to generate the first control potential; and a second amplifier amplifies the feedback potential by a second gain factor to generate the second control potential; wherein both the first amplifier and the second amplifier are powered by the output potential.

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