Power supply and its operating method

Abstract

The present invention provides a power supply device equipped with a power converter, a feedback circuit, a control signal generation circuit, and a compensation circuit. [Solution] The power converter generates an output voltage at the output node. The feedback circuit generates a feedback signal based on the output node voltage. The control signal generation circuit provides a control signal to the power converter based on the feedback signal. The compensation circuit includes a reference voltage circuit, a voltage divider circuit, and a switch circuit. When the output node voltage drops from a first voltage level to a level threshold, or from a first voltage level to an amplitude threshold, the switch circuit is turned on to couple the feedback circuit to the voltage divider circuit, thereby causing the feedback circuit to achieve at least one of the following: an improvement in the duty cycle of the control signal and a decrease in the frequency of the control signal.

Description

Technical Field

[0001] The present invention relates to a power supply, and particularly to a power supply that can quickly compensate for fluctuations in the output node voltage.

Background Art

[0002] A power supply can be used to convert voltage and supply a stable voltage to a load. However, when the load of the power supply is a device such as a motor, or in an application where a plurality of power supplies are connected in parallel to supply power, due to reasons such as the motor generating a back electromotive force or one of the plurality of power supplies operating abnormally, a state higher than the set output voltage value may occur at the output end of the power supply. For example, even when the preset output voltage value of the power supply is 24V, due to the abnormal operation of another power supply connected in parallel, the voltage value at the output end of the power supply may become 30V. For the sake of easy explanation, hereinafter, a state where the voltage at the output end of the power supply is raised due to external factors is called voltage reverse inflow. When the voltage reverse inflow phenomenon occurs in a conventional power supply, the voltage value at the output end significantly increases, and as a result, the power supply reduces power supply or temporarily stops power supply. When the voltage reverse inflow phenomenon disappears, for the power supply to recover from the state of reducing power supply or temporarily stopping power supply to a normal power supply state, a certain response time is required, and thereby, the voltage at the output end significantly decreases, and in some cases, the load may decrease beyond the allowable specifications, causing malfunction or damage to the load.

Summary of the Invention

[0003] How to solve the above technical problems caused by voltage reverse inflow in a power supply is an important issue that is urgently needed in the art.

[0004] This disclosure provides a power supply used to be coupled to an output node to supply power to a load. The power supply comprises a power converter, a feedback circuit, a control signal generation circuit, and a compensation circuit. The power converter is used to generate an output voltage to the output node based on an input voltage. The feedback circuit is coupled to the output node and generates a corresponding feedback signal based on the output node voltage of the output node. The control signal generation circuit is coupled to the power converter and provides a corresponding control signal to the power converter based on the feedback signal to generate the output voltage. The compensation circuit is coupled to the output node and the feedback circuit. The compensation circuit includes a reference voltage circuit, a voltage divider circuit, and a switch circuit. The reference voltage circuit is coupled to the output node and is used to generate a corresponding reference voltage based on the output node voltage. The voltage divider circuit is coupled to the reference voltage circuit and is used to generate a corresponding voltage divider based on the reference voltage. The switch circuit is coupled to the voltage divider circuit and the feedback circuit. When the output node voltage rises from a preset voltage level to a first voltage level, and then falls from the first voltage level to a level threshold, or falls from the first voltage level by an amplitude threshold, the switch circuit is turned on to couple the feedback circuit to the voltage divider circuit, and the feedback circuit is configured to cause the control signal generation circuit to achieve at least one of the following: increasing the duty cycle of the control signal and decreasing the frequency of the control signal.

[0005] This disclosure provides a method for operating a power supply, the power supply being used to be coupled to an output node to supply power to a load, the power supply including a power converter coupled to the output node, a feedback circuit coupled to the output node, a control signal generation circuit coupled to the power converter, and a compensation circuit coupled to the output node and the feedback circuit, the compensation circuit including a reference voltage circuit coupled to the output node, a voltage divider circuit coupled to the reference voltage circuit, and a switch circuit coupled to the voltage divider circuit and the feedback circuit, the method of operation including configuring the power converter to generate an output voltage at the output node based on an input voltage, configuring the feedback circuit to generate a corresponding feedback signal based on the output node voltage of the output node, and the feed The control signal generation circuit is configured to provide a corresponding control signal to the power converter based on a back signal to generate the output voltage; the reference voltage circuit is configured to generate a corresponding reference voltage based on the output node voltage; and the voltage divider circuit is configured to generate a corresponding voltage divider based on the reference voltage. When the output node voltage rises from a preset voltage level to a first voltage level and then falls from the first voltage level to a level threshold, or falls from the first voltage level by an amplitude threshold, the switch circuit is turned on to couple the feedback circuit to the voltage divider circuit, thereby causing the control signal generation circuit to achieve at least one of the following: increasing the duty cycle of the control signal and decreasing the frequency of the control signal.

[0006] The power supply and its operating method disclosed herein can rapidly adjust the output of the power converter to a desired voltage and / or current by controlling the feedback voltage with a compensation circuit after the voltage reverse inflow phenomenon has disappeared. Therefore, the power supply disclosed herein has the advantageous technical effect of rapidly stabilizing the output node voltage. [Brief explanation of the drawing]

[0007] [Figure 1] This is a schematic block diagram showing one embodiment of the power supply system according to the present disclosure. [Figure 2A] This waveform diagram shows the voltage at the output node of a conventional power supply. [Figure 2B] This waveform diagram shows one embodiment of the voltage at the output node of the power supply according to the present disclosure. [Figure 3] This is a schematic block diagram showing one embodiment of a compensation circuit and a feedback circuit. [Figure 4] Figure 3 is a partial circuit diagram showing one embodiment of the compensation circuit and feedback circuit. [Figure 5] This is a partial circuit diagram showing one embodiment of a feedback circuit. [Modes for carrying out the invention]

[0008] Embodiments of this disclosure will be described below with reference to the relevant drawings. In the drawings, the same reference numerals indicate the same or similar elements or method flows.

[0009] Figure 1 is a schematic block diagram showing one embodiment of the power supply system 100 according to the present disclosure. In this embodiment, the power supply system 100 includes power supply units PSU1 to PSU3. Power supply units PSU1 to PSU3 supply power to the load LD1 in parallel, for example, by being coupled to a bus bar or the like via connectors. Power supply unit PSU1 is coupled to the load LD1 via output node ND1. Power supply unit PSU1 includes a feedback circuit 115, a control signal generation circuit 117, a compensation circuit 120, and a power converter 130. The feedback circuit 115 is coupled to output node ND1 and control signal generation circuit 117. The compensation circuit 120 is coupled to output node ND1 and feedback circuit 115. The power converter 130 is coupled to control signal generation circuit 117 and output node ND1. The power converter 130 may be a suitable power converter such as an AC-DC converter or a DC-DC converter.

[0010] The number of power supplies in the power supply system 100 is not limited to three. In some embodiments, the number of power supplies in the power supply system 100 may be as few as one; for example, the power supply system 100 includes only one power supply PSU1. In this case, the output node ND1 of the power supply system 100 may experience a voltage reverse inflow phenomenon due to factors such as back electromotive force from the load LD1.

[0011] As shown in Figure 1, the power converter 130 receives the input voltage Vin, converts the input voltage Vin to the output voltage Vout, transmits the output voltage Vout to the output node ND1, and generates the output node voltage VND1 at the output node ND1. The feedback circuit 115 receives the output node voltage VND1 from the output node ND1 and generates a feedback signal FB correspondingly according to the voltage level of the output node voltage VND1. The control signal generation circuit 117 receives the feedback signal FB and generates a control signal Vctrl correspondingly to control the power converter 130 to generate the output voltage Vout correspondingly.

[0012] Following the above embodiment, the control signal generation circuit 117 receives a feedback signal FB and generates a control signal Vctrl based on the feedback signal FB. In some embodiments, when the output node voltage VND1 rises and the feedback signal FB is adjusted accordingly, the control signal generation circuit 117 controls the power converter 130 to lower the output node voltage VND1 to a desired voltage level by methods such as lowering the duty cycle of the control signal Vctrl and / or increasing the frequency of the control signal Vctrl. In other embodiments, when the output node voltage VND1 falls and the feedback signal FB is adjusted accordingly, the control signal generation circuit 117 controls the power converter 130 to raise the output node voltage VND1 to a desired voltage level by methods such as increasing the duty cycle of the control signal Vctrl and / or lowering the frequency of the control signal Vctrl.

[0013] In this embodiment, the control signal Vctrl may employ an appropriate signal format such as a pulse-width modulation (PWM) signal, a pulse-frequency modulation (PFM) signal, or a pulse-skip modulation (PSM) signal.

[0014] For example, if the control signal Vctrl employs pulse width modulation, the power converter 130 receives the control signal Vctrl from the control signal generation circuit 117 and adjusts the output voltage Vout based on the control signal Vctrl to correspondingly adjust the output node voltage VND1. If the control signal generation circuit 117 reduces the duty cycle of the control signal Vctrl, the power converter 130 operates based on the reduced duty cycle to reduce the output voltage Vout and correspondingly reduce the output node voltage VND1. If the control signal generation circuit 117 increases the duty cycle of the control signal Vctrl, the power converter 130 operates based on the increased duty cycle to increase the output voltage Vout and correspondingly increase the output node voltage VND1.

[0015] The compensation circuit 120 can adjust the feedback signal FB based on the output node voltage VND1. In one embodiment, the output node voltage VND1 of output node ND1 may rise due to abnormal operation of power supply PSU2 and / or power supply PSU3, or due to back electromotive force from load LD1. After the voltage reverse inflow phenomenon disappears, the output node voltage VND1 of output node ND1 decreases.

[0016] Please refer to Figures 2A and 2B. Figure 2A is a waveform diagram showing the voltage at the output node of a conventional power supply, and Figure 2B is a waveform diagram showing one embodiment of the voltage at the output node ND1 of the power supply PSU1 according to this disclosure.

[0017] In Figure 2A, when a voltage reverse inflow phenomenon occurs, the output node voltage Vo_pri of the conventional technology rises from the preset voltage level Vpre1 ​​output by the power supply to voltage level Vlev1. After time T1, the voltage reverse inflow phenomenon disappears. Because the conventional power supply cannot immediately supply power, the output node voltage Vo_pri drops from voltage level Vlev1 to voltage level Vlev2. Furthermore, the conventional power supply cannot improve its power supply capacity until a certain period of time has elapsed, which causes the output node voltage Vo_pri to recover from voltage level Vlev2 to the preset voltage level Vpre1. Voltage level Vlev2 is lower than the preset voltage level Vpre1, which fails to meet the system specifications and may cause load malfunction or damage.

[0018] In Figure 2B, when a voltage reverse inflow phenomenon occurs, the output node voltage VND1 of output node ND1 also rises from the preset voltage level Vpre1 ​​to the voltage level Vlev1. After time T1, when the voltage reverse inflow phenomenon disappears, the output node voltage VND1 falls from the voltage level Vlev1. At time T2, the compensation circuit 120 detects that the decrease in output node voltage VND1 exceeds the amplitude threshold AM_T1, or that the output node voltage VND1 has fallen to or below the level threshold LEV_TH, and controls the feedback circuit 115 to generate a corresponding feedback signal FB. The control signal generation circuit 117 then operates by increasing the duty cycle of the control signal Vctrl and / or decreasing the frequency of the control signal Vctrl based on the feedback signal FB. During the period from time T2 to time T3, the power converter 130 operates by increasing the duty cycle of the control signal Vctrl and / or decreasing the frequency of the control signal Vctrl, thereby rapidly improving the power supply capability to output node ND1. From time point T3 onward, the voltage at output node ND1 stops decreasing and is maintained at the preset voltage level Vpre1. Therefore, the output node voltage VND1 never falls below the preset output voltage of the power supply system 100. In another embodiment, the output node voltage VND1 of output node ND1 first falls below the preset voltage level Vpre1 ​​of the power supply system 100 (but within a system acceptable range), and then rises again to the preset voltage level Vpre1. In the embodiments of Figures 2A and 2B, the output node voltages are shown as straight lines for ease of explanation, but in reality, the change may not be as linear as in Figures 2A and 2B.

[0019] In this embodiment, the level threshold LEV_TH of the compensation circuit 120 can be set between the voltage level Vlev1 and the preset voltage level Vpre1. Alternatively, the amplitude threshold AM_T1 can be set by the compensation circuit 120, and the amplitude threshold AM_T1 may be the voltage difference between the preset voltage level Vpre1 ​​and the level threshold LEV_TH.

[0020] Summarizing the above, after the reverse voltage input phenomenon disappears, the power supply unit PSU1 in FIG. 1 immediately adjusts the feedback signal FB via the compensation circuit 120, and operates in a manner such as improving the duty ratio and / or reducing the frequency of the control signal Vctrl before the output node voltage VND1 of the power converter 130 drops to the preset voltage level Vpre1. Therefore, after the reverse voltage input phenomenon disappears, the power supply system 100 does not reduce or slightly lower the output node voltage VND1 below the preset voltage level Vpre1, and has the advantage of stabilizing the output node voltage.

[0021] FIG. 3 is a block schematic diagram of an embodiment of the compensation circuit 120 and the feedback circuit 115, and FIG. 4 is a partial circuit diagram of an embodiment of the compensation circuit 120 and the feedback circuit 115 in FIG. 3.

[0022] In the embodiment of FIG. 3, the compensation circuit 120 includes a reference voltage circuit REF1, a voltage dividing circuit DIV1, and a switch circuit SWC1. The reference voltage circuit REF1 is coupled to the output node ND1. The voltage dividing circuit DIV1 is coupled to the reference voltage circuit REF1. The switch circuit SWC1 is installed between the voltage dividing circuit DIV1 and the feedback circuit 115. The reference voltage circuit REF1 sets a reference voltage Vref based on the output node voltage VND1. The voltage dividing circuit DIV1 generates a divided voltage Vdiv based on the reference voltage Vref. The switch circuit SWC1 receives the divided voltage Vdiv from the voltage dividing circuit DIV1 and determines whether to conduct based on the divided voltage Vdiv.

[0023] In the embodiment of FIG. 4, the reference voltage circuit REF1 includes a diode D1 and a capacitor CD1. The cathode end of the diode D1 is coupled to the output node ND1, and the anode end of the diode D1 is coupled to the voltage dividing circuit DIV1. The first end of the capacitor CD1 is coupled to the output node ND1, and the second end of the capacitor CD1 is coupled to the anode end of the diode D1. The capacitor CD1 can be used to store charge, and the voltage at the connection point between the capacitor CD1 and the voltage dividing circuit DIV1 is the reference voltage Vref. The diode D1 is a Zener diode. By selecting an appropriate voltage level of the breakdown voltage of the diode D1, a limiting voltage value is set, and the limiting voltage value is set to an appropriate voltage value greater than the preset voltage level Vpre1 of the output node ND1.

[0024] The voltage dividing circuit DIV1 includes a resistor RD1 and a resistor RD2. The first end of the resistor RD1 is coupled to the reference voltage circuit REF1, and the second end of the resistor RD1 is coupled to the first end of the resistor RD2. The second end of the resistor RD2 is coupled to the ground terminal GND. In this embodiment, the voltage at the first end of the resistor RD2 is the divided voltage Vdiv, and the divided voltage Vdiv can be represented by Equation (1).

Equation

[0025] The switch circuit SWC1 includes a transistor BJT1. The first terminal of transistor BJT1 is coupled to the second terminal of resistor RD1 and the first terminal of resistor RD2, the second terminal of transistor BJT1 is coupled to the feedback circuit 115, and the third terminal of transistor BJT1 is coupled to the ground terminal GND. In this embodiment, transistor BJT1 may be an NPN bipolar junction transistor (BJT), the first terminal of transistor BJT1 may be the emitter, the second terminal of transistor BJT1 may be the collector, and the third terminal of transistor BJT1 may be the base. The conduction condition for transistor BJT1 is that the crossover voltage from the third terminal to the first terminal is greater than the threshold voltage of transistor BJT1. Since the third terminal of transistor BJT1 is coupled to the ground terminal GND, the conduction condition for transistor BJT1 is that the voltage at the first terminal is less than one negative of the threshold voltage of transistor BJT1.

[0026] Since the first terminal of transistor BJT1 is coupled to the first terminal of resistor RD2, the voltage at the first terminal of transistor BJT1 is equal to the divided voltage Vdiv. In other words, the conduction condition for transistor BJT1 is that the divided voltage Vdiv is lower than negative 1 times the threshold voltage of transistor BJT1. Furthermore, the divided voltage Vdiv is generated based on the reference voltage Vref, which is influenced by the output node voltage VND1. The voltage value of the divided voltage Vdiv corresponds to the output node voltage VND1, which in turn determines whether transistor BJT1 conducts. Combining Equation 1, the conduction condition for transistor BJT1 is given by Equation 2, where Vth represents the threshold voltage of transistor BJT1.

number

[0027] In the embodiments of FIGS. 3 and 4, when the output node voltage VND1 on the output node ND1 is substantially the preset voltage level Vpre1, if the limiting voltage value of the reference voltage circuit REF1 (for example, the breakdown voltage of the diode D1) is set to be not less than the preset voltage level Vpre1, the reference voltage Vref and the correspondingly generated divided voltage Vdiv are substantially equal to the voltage of the ground terminal GND, or the voltage difference between the voltage of the ground terminal GND and the divided voltage Vdiv is smaller than the threshold voltage of the transistor BJT1 (that is, Vgnd - Vdiv < Vth or Vdiv > Vgnd - Vth, where Vgnd represents the voltage of the ground terminal GND), so the switch circuit SWC1 is turned off.

[0028] When the output node voltage VND1 on the output node ND1 rises from the preset voltage level Vpre1 to the voltage level Vlev1 (as shown in FIG. 2B), since the voltage level Vlev1 is greater than the breakdown voltage of the diode D1, the diode D1 conducts in the reverse direction, and the voltage difference across the capacitor CD1 becomes equal to the breakdown voltage of the diode D1. At this time, the reference voltage Vref is equal to the value obtained by subtracting the breakdown voltage from the output node voltage VND1. Since the difference between the output node voltage VND1 and the breakdown voltage is positive, the divided voltage Vdiv generated by the voltage dividing circuit DIV1 based on the reference voltage Vref is at a positive voltage level, and the voltage difference between the voltage of the ground terminal GND and the divided voltage Vdiv is smaller than the threshold voltage of the transistor BJT1. Therefore, since the transistor BJT1 is non-conducting, the switch circuit SWC1 also does not conduct.

[0029] When the reverse voltage inflow phenomenon disappears (as shown at time T1 in Figure 2B), the output node voltage VND1 on the output node ND1 falls below the breakdown voltage of diode D1 from the voltage level Vlev1, and diode D1 ceases to conduct in the reverse direction. At this time, since the output node voltage VND1 is smaller than the breakdown voltage of diode D1, the difference between the output node voltage VND1 and the breakdown voltage becomes negative, the reference voltage Vref is at a negative voltage level, and the voltage divider voltage Vdiv also becomes at a corresponding negative voltage level. The decrease in the output node voltage VND1 lowers the reference voltage Vref, making the voltage difference between the voltage at the ground terminal GND and the voltage divider voltage Vdiv greater than the threshold voltage of transistor BJT1, and further causing transistor BJT1 and the switch circuit SWC1 to conduct, and the voltage divider circuit DIV1 is coupled to the feedback circuit 115. As a result, the feedback circuit 115 can adjust the feedback signal FB in immediate response to the decrease in the output node voltage VND1.

[0030] When the control signal generation circuit 117 increases the duty cycle of the control signal Vctrl and / or decreases the frequency of the control signal Vctrl based on the feedback signal FB (at least one can be employed depending on the circuit architecture of the power converter 130), the power supply capability of the power converter 130 is improved, and the output voltage Vout of the power converter 130 eventually returns to the preset voltage level Vpre1. As a result, the divided voltage Vdiv becomes higher than -1 times the threshold voltage of transistor BJT1, and transistor BJT1 and switch circuit SWC1 cease to conduct.

[0031] Figure 5 is a partial circuit diagram of one embodiment of the feedback circuit 115.

[0032] The feedback circuit 115 includes a shunt regulator Z1, resistors R1 to R4, and a light-emitting diode LED1. The first end of resistor R1 is connected to the output node ND1, and the second end of resistor R1 is connected to the first end of resistor R2 and the anode terminal of the light-emitting diode LED1. The second end of resistor R2 and the cathode terminal of the light-emitting diode LED1 are connected to the cathode terminal of the shunt regulator Z1. The control terminal of the shunt regulator Z1 is connected to the feedback node N_FB, and the anode terminal of the shunt regulator Z1 is connected to the ground terminal GND. The first end of resistor R3 is connected to the output node ND1, and the second end of resistor R3 is connected to the feedback node N_FB. The first end of resistor R4 is connected to the feedback node N_FB, and the second end of resistor R4 is connected to the ground terminal GND.

[0033] In the embodiment shown in Figure 5, the feedback circuit 115 is implemented by combining a shunt voltage stabilization circuit with other circuit elements. Based on the output node voltage VND1 of the output node ND1, it correspondingly changes the current flowing through the light-emitting diode LED1 to adjust the light emission signal of the light-emitting diode LED1, and transmits the light emission signal as a feedback signal FB to the control signal generation circuit 117. As a result, the control signal generation circuit 117 generates a corresponding control signal Vctrl and causes the power converter 130 to adjust its output voltage Vout.

[0034] Furthermore, the feedback node N_FB is coupled to the compensation circuit 120. For example, the feedback node N_FB is coupled to the collector of the transistor BJT1 of the switch circuit SWC1 in the embodiment shown in Figure 4. When the switch circuit SWC1 of the compensation circuit 120 is not conducting, resistors R3 and R4 divide the output node voltage VND1 on the output node ND1 to set up a shunt voltage stabilization circuit Z1, which sets the current flowing through the light-emitting diode LED1 and causes the feedback circuit 115 to generate a feedback signal FB. When the switch circuit SWC1 of the compensation circuit 120 conducts, the first terminal of resistor RD2 of the compensation circuit 120 conducts to the feedback node N_FB of the feedback circuit 115, making the equivalent resistance between the feedback node N_FB and the ground terminal GND (for example, the equivalent resistance of resistor RD2 and resistor R4 in parallel) smaller than the resistance of resistor R4. As a result, the voltage divided across the feedback node N_FB from the output node voltage VND1 becomes smaller than the voltage when the switch circuit SWC1 is not conducting. Consequently, the shunt voltage stabilization circuit Z1 increases the current flowing through the light-emitting diode LED1, causing the control signal generation circuit 117 and the power converter 130 to immediately start supplying power or improve their power supply capability.

[0035] In one embodiment, since at least a portion of the control signal generation circuit 117 and the feedback circuit 115 are implemented as an integrated circuit, the feedback circuit 115 can adjust the feedback signal FB in response to changes in the output node voltage VND1. However, the integrated circuit is not well-suited to different application scenarios and cannot quickly address the aforementioned problem of instability of the output node voltage VND1 due to reverse voltage inflow. Therefore, in such an embodiment of the integrated circuit, the power supply PSU1 of the present disclosure includes a compensation circuit 120 that can be used in cooperation with the feedback circuit 115 to more quickly adjust the feedback signal FB and the output voltage of the power converter 130 based on the output node voltage VND1. Therefore, after the voltage reverse inflow phenomenon occurs and disappears, the power supply PSU1 of the present disclosure quickly adjusts the impedance value of the feedback circuit 115 through the compensation circuit 120 (for example, in the embodiment of Figure 5, conducts the first end of resistor RD2 and the feedback node N_FB of the feedback circuit 115), and correspondingly adjusts the feedback signal FB, improving the duty cycle of the control signal Vctrl and / or decreasing the frequency of the control signal Vctrl, so that the power converter 130 can start power supply or improve power supply capability by operating based on the improved duty cycle and / or decreased frequency of the control signal Vctrl before the output node voltage VND1 drops to the preset voltage level Vpre1. In another embodiment, the switch circuit SWC1 of the compensation circuit 120 may be set to conduct when the output node voltage VND1 falls below the amplitude threshold AM_T1, thereby quickly adjusting the impedance value of the feedback circuit 115 and correspondingly adjusting the feedback signal FB and the control signal Vctrl, so that the power converter 130 starts supplying power based on the improved duty cycle and / or lower frequency of the control signal Vctrl before the output node voltage VND1 falls to the preset voltage level Vpre1, and the power converter 130 can also improve its power supply capability at this point. Thus, the power supply unit of the present disclosure has the advantageous technical effect of ensuring that the output node voltage does not exceed the operating specifications of the power supply system 100.

[0036] In the specification and claims, specific terms are used to refer to certain elements. However, those skilled in the art will understand that the same element may be referred to by different names. The specification and claims use functional differences of the elements, not differences in names, as the basis for distinction. The word "includes" as used in the specification and claims is an open expression and should be interpreted as "includes, but not limited to."

[0037] Furthermore, unless otherwise specified in the specification, singular terms shall also include the plural meaning.

[0038] The foregoing are merely preferred embodiments of the Disclosure, and various modifications and equivalent changes can be made to the Disclosure without departing from the scope or spirit of the Disclosure. In short, any modifications and equivalent changes made to the Disclosure within the scope of the following claims are all covered by the Disclosure. [Explanation of Symbols]

[0039] 100: Power supply system PSU1, PSU2, PSU3: Power supply LD1:Load 115: Feedback Circuit 117: Control signal generation circuit 120: Compensation circuit 130: Power converter Vin: Input voltage FB: Feedback signal Vout: Output voltage VND1, Vo_pri: Output node voltage Vctlm: Control signal ND1: Output node Vlev1, Vlev2: Voltage levels Vpre1: Preset voltage level AM_T1: Amplitude threshold LEV_TH: Level threshold T1, T2, T3: Time points REF1: Reference voltage circuit DIV1: Voltage divider circuit SWC1: Switch Circuit Vref: Reference voltage Vdiv: divided voltage D1: Diode CD1: Capacitor RD1, RD2, R1, R2, R3, R4: Resistance BJT1: Transistor GND: Ground terminal Z1: Shunt-type voltage stabilization circuit LED1: Light-emitting diode N_FB: Feedback node

Claims

1. A power supply unit used to be coupled to an output node to supply power to a load, A power converter used to generate an output voltage at the output node based on the input voltage, A feedback circuit coupled to the output node and used to generate a corresponding feedback signal based on the output node voltage of the output node, A control signal generation circuit coupled to the power converter and providing a corresponding control signal to the power converter based on the feedback signal to generate the output voltage, A compensation circuit coupled to the output node and the feedback circuit, Equipped with, The aforementioned compensation circuit is A reference voltage circuit coupled to the output node and used to generate a corresponding reference voltage based on the output node voltage, A voltage divider circuit coupled to the aforementioned reference voltage circuit and used to generate corresponding voltage dividers based on the aforementioned reference voltage, A switch circuit coupled to the voltage divider circuit and the feedback circuit, Includes, A power supply in which, when the output node voltage rises from a preset voltage level to a first voltage level and then falls from the first voltage level to a level threshold, or falls from the first voltage level by an amplitude threshold, the switch circuit is turned on and the feedback circuit is coupled to the voltage divider circuit, thereby causing the feedback circuit to the control signal generation circuit to achieve at least one of the following: increasing the duty cycle of the control signal and decreasing the frequency of the control signal.

2. The power supply according to claim 1, wherein when the output node voltage decreases, the feedback circuit is configured to generate a feedback signal to correspondingly increase the duty cycle of the control signal and decrease the frequency of the control signal, thereby configuring the control signal generation circuit to cause the power converter to increase the output voltage, and when the output node voltage increases, the feedback circuit is configured to generate a feedback signal to correspondingly decrease the duty cycle of the control signal and increase the frequency of the control signal, thereby configuring the control signal generation circuit to cause the power converter to decrease the output voltage.

3. The power supply according to claim 2, wherein the feedback circuit includes a light-emitting diode, and generates the feedback signal in correspondence based on the current flowing through the light-emitting diode.

4. The aforementioned voltage divider circuit is A first resistor coupled to the reference voltage circuit and the switch circuit, A second resistor is provided between the switch circuit, the first resistor and the ground terminal, Equipped with, The power supply according to claim 3, wherein when the switch circuit is turned on, the switch circuit connects the second resistor to the feedback circuit to change the current flowing through the light-emitting diode.

5. The power supply according to claim 4, wherein when the switch circuit is turned on, the current flowing through the light-emitting diode increases, and the control signal generation circuit increases the output voltage of the power converter based on the feedback signal.

6. A method for operating a power supply unit, The power supply is used to be coupled to an output node to supply power to a load, and the power supply includes a power converter coupled to the output node, a feedback circuit coupled to the output node, a control signal generation circuit coupled to the power converter, and a compensation circuit coupled to the output node and the feedback circuit, the compensation circuit includes a reference voltage circuit coupled to the output node, a voltage divider circuit coupled to the reference voltage circuit, and a switch circuit coupled to the voltage divider circuit and the feedback circuit, and the operation method is, The power converter is installed to generate an output voltage at the output node based on the input voltage, The feedback circuit is configured to generate a corresponding feedback signal based on the output node voltage of the output node, The control signal generation circuit is configured to provide a corresponding control signal to the power converter based on the feedback signal to generate the output voltage, The reference voltage circuit is configured to generate a corresponding reference voltage based on the output node voltage, The voltage divider circuit is configured to generate corresponding voltage dividers based on the aforementioned reference voltage, Equipped with, A method of operating a power supply, wherein when the output node voltage rises from a preset voltage level to a first voltage level, and then falls from the first voltage level to a level threshold, or falls from the first voltage level by an amplitude threshold, the switch circuit is turned on to couple the feedback circuit to the voltage divider circuit, thereby causing the feedback circuit to achieve at least one of the following in correspondence to the control signal generation circuit: an improvement in the duty cycle of the control signal and a decrease in the frequency of the control signal.

7. When the output node voltage decreases, the feedback circuit is configured to generate a feedback signal to correspondingly increase the duty cycle of the control signal and decrease the frequency of the control signal, thereby configuring the control signal generation circuit to cause the power converter to increase the output voltage. When the output node voltage rises, the feedback circuit is configured to generate a feedback signal to correspondingly reduce the duty cycle of the control signal and increase the frequency of the control signal, thereby configuring the control signal generation circuit to cause the power converter to reduce the output voltage. The operating method according to claim 6, further comprising:

8. The feedback circuit includes a light-emitting diode, The aforementioned operation method is, The operating method according to claim 7, further comprising generating the feedback signal in correspondence based on the current flowing through the light-emitting diode.

9. The voltage divider circuit includes a first resistor and a second resistor, the first resistor being coupled to the reference voltage circuit and the switch circuit, and the second resistor being provided between the switch circuit, the first resistor and the ground terminal. The aforementioned operation method is, The operating method according to claim 8, further comprising the following: when the switch circuit is turned on, the switch circuit couples the second resistor to the feedback circuit to change the current flowing through the light-emitting diode.

10. The operating method according to claim 9, further comprising increasing the current flowing through the light-emitting diode when the switch circuit is turned on, and causing the control signal generation circuit to increase the output voltage of the power converter based on the feedback signal.

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