Power supply system and power supply method

Abstract

The invention provides a power supply system and a power supply method. In one embodiment, the power supply system includes a first rectifier filter, a second rectifier filter, and a power management module. The first rectifier filter is connected to a first winding and is used for providing an output power supply. The second rectifier filter is connected to an auxiliary winding for providing an auxiliary power supply. The auxiliary winding is inductively coupled with the first winding. The number of turns of the first winding is greater than the number of turns of the auxiliary winding. The power management module is connected to the auxiliary power supply and the output power supply, and selects or does not select the output power supply as an input power supply according to one of an operation power supply and the output power supply. The input power supply is used for enabling the power management module to generate and regulate the operation power supply.

Description

TECHNICAL FIELD

[0001] The present application relates to a power supply system capable of generating an operating power supply, and in particular, to a power supply system capable of generating an operating power supply efficiently when a high output power supply is required, and a related power supply method. BACKGROUND

[0002] PD (Power Delivery) fast charging is a fast charging technology published by the USB (Universal Series Bus) Implementers Forum (USB-IF). PD fast charging charges through a USB-C port, and is quite widely applicable to various devices, and is often used in laptops, medical devices, power tools, etc. in addition to being supported by the charging specifications of iPhones / iPads.

[0003] The extended power range (EPR) of the PD 3.1 version allows a USB type-C port to provide power up to 240 watts, and defines a maximum output voltage of 48V and a minimum output voltage of 5V. Figure 1 A power supply system 100 conforming to PD 3.1 is shown. In other words, the output power supply V CC in the power supply system 100 can be as high as 48V and as low as 5V.

[0004] By storing and releasing energy in the transformer 102, the rectifier filter 104 rectifies the current generated by the secondary side winding of the transformer 102, and establishes an output power supply V CC between the output terminal VCC and the ground terminal GND. The USB PD controller 101 communicates with another USB PD controller connected to the other end of the USB type-C connection line (not shown) through the channel configuration lines CC1 and CC2 in the USB type-C connector 108, and determines the specifications of the output power supply V CC . When the output power supply V CC is ready, the power switch 106 is turned on, so that the output power supply V CC serves as a bus power supply V BUS on the bus power line VBUS to supply power to an electronic product at the other end. As shown in Figure 1 , the USB PD controller 101 has a linear regulator (LDO) 110. The linear regulator 110 generates an operating power supply V CC with a voltage of about V DD(5V, for example) to power the internal logic circuit 112 of the USB PD controller 101.

[0005] Figure 1 the USB PD controller 101 in the output power supply V CC 48V, will consume a relatively much larger power than when the output power supply V CC 5V. For example, the current consumed by the logic circuit 112 is roughly fixed, say 5 milliampere. Then when the output power supply V CC 48V, the power consumption of the USB PD controller 101 is about 48*5 milliampere; and when the output power supply V CC 5V, the power consumption of the USB PD controller 101 is about 5*5 milliampere. SUMMARY

[0006] The embodiment of the present application provides a power supply system, which includes a first rectifier filter, a second rectifier filter, and a power management module. The first rectifier filter is connected to a first winding to provide an output power supply. The second rectifier filter is connected to an auxiliary winding to provide an auxiliary power supply. The auxiliary winding is inductively coupled to the first winding. A first winding turn number of the first winding is greater than an auxiliary winding turn number of the auxiliary winding. The power management module is connected to the auxiliary power supply and the output power supply to select or not select the output power supply as an input power supply according to one of an operating power supply and the output power supply. The input power supply is used to make the power management module generate and regulate the operating power supply.

[0007] The embodiment of the present application provides a power supply method to generate an operating power supply. The power supply method includes: providing a first winding and an auxiliary winding inductively coupled, wherein a first winding turn number of the first winding is greater than an auxiliary winding turn number of the auxiliary winding; rectifying a first winding current of the first winding to generate an output power supply; rectifying an auxiliary winding current of the auxiliary winding to generate an auxiliary power supply; selecting or not selecting the output power supply as an input power supply according to one of the operating power supply and the output power supply; and using the input power supply to provide power to establish and regulate the operating power supply on a power line. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1 A known power supply system 100 that complies with PD 3.1 is shown.

[0009] Figure 2 A power supply system 200 according to an embodiment of the present application is shown.

[0010] Figure 3A and 3BA two-power management module implemented according to the present application is shown.

[0011] Figure 4 A one-power management module is shown. Figure 5 A one-power management module implemented according to the present application is shown.

[0012] Figure 6 A one-power management module is shown. Figure 7 Another one-power management module implemented according to the present application is shown.

[0013] Figure 8 A power supply system 300 implemented according to an embodiment of the present application is shown.

[0014] Figure 9 A one-power management module is shown. Figure 8 A one-power management module is shown.

[0015]

Symbol Description

[0016] 100 power supply system

[0017] 101 USB PD controller

[0018] 102 transformer

[0019] 104 rectifier filter

[0020] 106 power switch

[0021] 108 USB type-C connector

[0022] 110 linear voltage regulator

[0023] 112 logic circuit

[0024] 200 power supply system

[0025] 201 USB PD controller

[0026] 202 transformer

[0027] 204A, 204B rectifier filter

[0028] 205A, 205B winding

[0029] 206 power switch

[0030] 208 USB type-C connector

[0031] 210, 210A, 210B, 210C, 210D power management module

[0032] 211A, 211B detection circuit

[0033] 212 logic circuit

[0034] 214A, 214B, 214C, 214D, 214E, 214F linear voltage regulator

[0035] 300 power supply system

[0036] 301 USB PD controller

[0037] 304A, 304B, 304C rectifier filter

[0038] 305A, 305B, 305C winding

[0039] 306 power switch

[0040] 310 power management module

[0041] 314A, 314B, 314C linear voltage regulator

[0042] CC1, CC2 channel configuration line

[0043] CA, CO output capacitor

[0044] COM1 comparator

[0045] D1 diode

[0046] DA, DO rectifier diode

[0047] GND ground terminal

[0048] I A , I O current

[0049] OP1, OP2, OP3, OP4 operational amplifier

[0050] R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11

[0051] resistor

[0052] SW1, SW3 selection switch

[0053] SW5, SW6, SW7, SW8 power switch

[0054] V AUX , V AUX1 , V AUX2 auxiliary power supply

[0055] VAUX, VAUX1, VAUX2 auxiliary terminal

[0056] V BUS bus power supply

[0057] VBUS bus power line

[0058] V CC Output power

[0059] VCC output terminal

[0060] V DD Operating power supply

[0061] VDD power line

[0062] V REF1 、V REF2 、V REF3 、V REF4 、V REF5 Reference voltage DETAILED DESCRIPTION

[0063] To make the purpose, implementation, and advantages of the embodiments of the present invention more clear, the implementation in the embodiments will be described clearly and completely below with reference to the accompanying drawings of the embodiments. The embodiments described in this specification are only some embodiments of the present invention and are not all embodiments. Those skilled in the art may make various modifications and variations to the embodiments described in this specification without departing from the spirit and scope of the present invention.

[0064] Figure 2 The power supply system 200 according to an embodiment of the present invention is shown, which can provide an output power V compliant with PD 3.1. CC , can roughly maintain the output power supply V CC The highest is 48V and the lowest is 5V. Figure 2 The power supply system 200 and Figure 1 The similarities and similarities between the power supply system 100 and the power supply system 100 are apparent from the previous description and will not be repeated here. Although the present invention utilizes USB PD as an embodiment, the invention is not limited thereto and the embodiments of the present invention may also be applied to other power supply specifications or architectures. All equivalent variations and modifications made in accordance with the claims of the present invention are intended to be covered by the scope of the present invention.

[0065] exist Figure 2 In FIG. 2 , the power supply system 200 has rectifier filters 204A and 204B. The rectifier filter 204A is used to rectify the current I output by the winding 205A. O Rectification, used to provide output power V at the output terminal VCC CC Similarly, the rectifier filter 204B is used to rectify the current I output by the winding 205B. A Rectification, used to provide auxiliary power V at the auxiliary terminal VAUX AUXThe rectifier filter 204A has a rectifier diode DO and an output capacitor CO. The rectifier filter 204B has a rectifier diode DA and an output capacitor CA. The windings 205A and 205B are both of the transformer 202 and are inductively coupled to each other. The number of turns N 205A of the winding 205A is greater than the number of turns N 205B of the winding 205B. In the following embodiments, N 205A / N 205B is equal to 3.

[0066] The USB PD controller 201 is connected to the USB type-C connector 208 and has a power management module 210 in addition to controlling the power switch 206, connected to the output power source V CC and the auxiliary power source V AUX . The power management module 210 can select or not select the output power source V CC as the input power source, depending on the output power source V AUX , the auxiliary power source V DD , or the operating power source V CC . When the output power source V CC is not selected as the input power source, the auxiliary power source V AUX is the input power source. The input power source is used to provide power to establish the operating power source V DD on the power line VDD.

[0067] For example, it is assumed that the current consumed by the logic circuit 212 is approximately fixed at 5 milliampere. In an embodiment, when the output power source V CC is 48V and the auxiliary power source V AUX is 16V, which is already high enough to generate and regulate the operating power source V DD at approximately 5V, the power management module 210 does not select the output power source V CC , but the auxiliary power source V AUX is the input power source at this time, and the power consumption of the USB PD controller 201 is approximately 16*5 milliwatts; when the output power source V CC is 5V and the auxiliary power source V AUX is 1.67V, the auxiliary power source V AUX is already too low and insufficient to generate the 5V operating power source V DD , so the power management module 210 selects the output power source V CC as the input power source to generate and regulate the operating power source V DD at this time, and the power consumption of the USB PD controller 201 is approximately 5*5 milliwatts. Compared with the prior art, when the output power source V CCWhen the voltage is 48V, the power consumption of the USB PD controller 201 (16*5mW) is much lower than the power consumption of the USB PD controller 101 (48*5mW), thus saving energy.

[0068] In another embodiment, Figure 2 The rectifier diodes DO and DA can be replaced by synchronous rectifier switches. In one embodiment, the winding 205B is a part of the winding 205A. For example, the winding 205A is tapped in the middle and connected to the rectifier diode DA as one end of the winding 205B.

[0069] Example 1

[0070] Figure 3A The display power management module 210A can be used as Figure 2 FIG. 2 is an example of a power management module 210. The power management module 210A includes a detection circuit 211A, a selection switch SW1, a diode D1, and a linear regulator 214A.

[0071] The detection circuit 211A detects the auxiliary power supply V AUX Is the voltage high enough to select or not select the output power supply V through the selection switch SW1? CC As the input power supply. The series resistors R1 and R2 form a voltage divider, which divides the auxiliary power supply V AUX The voltage division result is provided to the comparator COM1. The structure of the detection circuit 211A is equivalent to setting a reference voltage V REF1 *(R1+R2) / R2 is a first preset voltage, where R1 and R2 are the resistance values ​​of resistors R1 and R2 respectively. In the following example, the first preset voltage is 5.3V. The detection circuit 211A is equivalent to comparing the auxiliary power supply V AUX and 5.3V. When the auxiliary power supply V AUX When the voltage is higher than 5.3V, the comparator COM1 turns off the switch SW1 and does not select the output power supply V CC As the input power supply. At this time, the auxiliary power supply V AUX The same is selected as the input power supply, which supplies power to the linear regulator 214A through the diode D1 to generate an operating power supply V of approximately 5V. DD In contrast, when the auxiliary power supply V AUX When it is lower than 5.3V, the comparator COM1 turns on the switch SW1, and the diode D1 is reverse biased, so the output power supply V CC is selected as the input power supply and provided to the linear regulator 214A to generate an operating power supply V of approximately 5V. DD .

[0072] In an embodiment, the detection circuit 211A can be configured with hysteresis to avoid the auxiliary power supply V AUX When the voltage is approximately equal to 5.3V, the output of the comparator COM1 switches its output logic value at a high frequency. For example, the detection circuit 211A only switches the output logic value when the auxiliary power supply V AUX When the auxiliary power supply V AUX When it drops below 5.3V, it will change to open the selection switch SW1.

[0073] Example 2

[0074] Figure 3B The display power management module 210B can be used as Figure 2 FIG2 is an example of a power management module 210 in FIG2 . Power management module 210B includes a detection circuit 211B, a selection switch SW3, a diode D3, and a linear regulator 214B. Similarities or similarities between power management module 210B and power management module 210A can be found in the previous description and are not repeated here.

[0075] The detection circuit 211B detects the output power V CC Is the voltage too high to select or not select the output power supply V CC As the input power supply, the architecture of the detection circuit 211B is equivalent to setting a reference voltage V REF2 *(R3+R4) / R4, where R3 and R4 are the resistance values ​​of resistors R3 and R4 respectively. In one example, the second preset voltage is 15.9V. When the output power V CC When it is higher than 15.9V, the auxiliary power supply V AUX It is also higher than 5.3V, the selection switch SW3 is closed, and the output power supply V CC is not selected as the input power supply, the auxiliary power supply V AUX is selected as the input power supply and supplies power to the linear regulator 214B through the diode D3. CC When it is lower than 15.9V, the switch SW3 is turned on and the output power V CC is selected as the input power supply and provided to the linear regulator 214B to generate an operating power supply V of approximately 5V. DD .

[0076] Example 3

[0077] Figure 4 The display power management module 210C can be used as Figure 2 The power management module 210C is an example of a power management module 210 in FIG. DD , to select or not select the output power supply VCC As input power.

[0078] The power management module 210C includes linear regulators 214C and 214D. The linear regulator 214C outputs a power supply V CC As the input power supply, it can be used to generate the operating power supply V DD , and can place the operating power supply V DD The linear regulator 214D is regulated to a relatively low preset voltage, which is 4.7V in the following example; the auxiliary power supply V AUX As the input power supply, it can be used to generate the operating power supply V DD , and can place the operating power supply V DD Regulate a relatively high preset voltage, 5V in the following example. Operating power supply V DD Either 4.7V or 5V can allow the logic circuit 212 to operate normally.

[0079] This architecture is equivalent to detecting the operating power supply V DD , to determine the auxiliary power supply V AUX Whether the voltage is high enough, the linear regulator 214C is automatically turned on or off. In other words, the output power V CC Automatically selected or not selected to be used as an input power source. If the operating power supply V DD It is stable at 5V. Since it is higher than 4.7V, the linear regulator 214C is automatically turned off and the output power supply V CC No power is supplied to the operating power supply V DD At this time, the auxiliary power supply V AUX Power supply, through the linear regulator 214D will operate the power supply V DD Regulated at 5V. If the operating power supply V DD Stable at 4.7V, that means the auxiliary power supply V AUX Too low, not enough to pull up the operating power supply V DD is higher than 4.7V, so the linear regulator 214C automatically works, and the output power supply V CC The power supply will operate the power supply V DD Regulated at 4.7V.

[0080] Figure 5 Examples Figure 4 The power management module 210C in the power supply. Resistors R5, R6, and R7 are connected in series to the operating power supply V DD and the ground line GND, and provide two end points, which are respectively connected to the operational amplifiers OP1 and OP2.

[0081] The linear regulator 214C is generally composed of a power switch SW5, an operational amplifier OP1, and resistors R5, R6, and R7. In one embodiment, the reference voltage V REF3*(R5+R6+R7) / (R6+R7) is equal to 4.7V, where R5, R6, and R7 are the resistance values ​​of resistors R5, R6, and R7 respectively. In simple terms, the operational amplifier OP1 compares the operating power supply V DD and 4.7V to control the power switch SW5.

[0082] Similarly, the linear regulator 214D is generally composed of a power switch SW6, an operational amplifier OP2, and resistors R5, R6, and R7. REF3 *(R5+R6+R7) / R6 equals 5V. In simple terms, the operational amplifier OP2 compares the operating power supply V DD and 5V to control the power switch SW6.

[0083] In another embodiment, the series resistors R5, R6, and R7 can be replaced by four resistors, two of which are connected in series to form two voltage dividers. The two voltage dividers provide feedback voltages to the negative input terminals of the operational amplifiers OP1 and OP2, respectively, so that the linear regulators 214C and 214D can respectively regulate the operating power supply V DD At 4.7V vs. 5V.

[0084] Example 4

[0085] Figure 6 The display power management module 210D can be used as Figure 2 The power management module 210D can be configured to provide a power supply according to the auxiliary power supply V AUX Whether there is enough voltage determines whether the output power supply V CC Draw power.

[0086] The power management module 210D has linear regulators 214E and 214F. The linear regulator 214E outputs a power supply V CC As an input power supply, it can be used to generate auxiliary power supply V AUX and the auxiliary power supply V AUX is regulated at a preset voltage, which is 5.3V in the following example. In this embodiment, the auxiliary power supply V AUX The output power supply V CC Power supply to establish, or may be Figure 2 The winding 205B is powered by the rectifier filter 204B. The linear regulator 214F is used to supply the auxiliary power supply V AUX As the input power supply, it can be used to generate the operating power supply V DD , and can place the operating power supply V DD The voltage is controlled at a preset value, which is 5V in the following example.

[0087] This architecture allows the linear regulator 214E to follow the auxiliary power supply V AUX If the auxiliary power supply V AUX The voltage of the auxiliary power supply V AUX If the voltage is higher than 5.3V, the linear regulator 214E will automatically shut down and the output power V CC No power supply to convert to auxiliary power supply V AUX When the winding 205B cannot make the auxiliary power supply V AUX When the voltage is maintained above 5.3V, the linear regulator 214E will automatically work, and the output power supply V CC Power supply, it is hoped that the auxiliary power supply V AUX Pull up to 5.3V.

[0088] Figure 7 Examples Figure 6 The power management module 210D in FIG. 214B is a linear regulator 214E composed of a power switch SW7, an operational amplifier OP3, and resistors R8 and R9. REF4 *(R8+R9) / R9 is equal to 5.3V, where R8 and R9 are the resistance values ​​of resistors R8 and R9 respectively. Simply put, the operational amplifier OP3 compares the auxiliary power supply V AUX and 5.3V to control the power switch SW7 to regulate the auxiliary power supply V AUX Approximately equal to 5.3V.

[0089] Similarly, the linear regulator 214F is generally composed of a power switch SW8, an operational amplifier OP4, and resistors R10 and R11. In short, the operational amplifier OP4 compares the operating power supply V DD and 5V to control the power switch SW8 to regulate the operating power supply V DD Approximately equal to 5V.

[0090] Figure 7 The power management module 210D in the embodiment has an advantage: the equivalent capacitance value on the output terminal VCC will change with the output power supply V CC When the output power supply V CC When the USB PD controller 201 regulates the voltage at 5V, the power switch SW7 will remain in the on state, so Figure 2 The output capacitor CA in the circuit will be connected in parallel with the output capacitor CO, and the output power supply V CC Providing a voltage regulation effect can cope with the transient response of large current changes. CC When the USBPD controller 201 is regulated at 20V, the power switch SW7 will remain in the off state, soFigure 2 The output capacitor CA is no longer connected in parallel with the output capacitor CO. Only the output capacitor CO provides the output power V CC Voltage regulation effect. Generally speaking, the output power supply V CC The lower the voltage, the greater the current change in the transient response.

[0091] Figure 2 The power supply system 200 has only one auxiliary power supply V AUX , but the present invention is not limited thereto, and in its embodiment, the present invention may have multiple auxiliary power supplies.

[0092] Example 5

[0093] Figure 8 The power supply system 300 according to an embodiment of the present invention is shown, which can provide an output power V compliant with PD 3.1. CC , can roughly maintain the output power supply V CC The highest is 48V and the lowest is 5V. Figure 2 The power supply system 300 and Figure 2 The same or similar aspects of the power supply system 200 can be known from the previous description and will not be repeated here.

[0094] exist Figure 8 In the embodiment, the power supply system 300 has rectifier filters 304A, 304B, and 304C, which can respectively provide output power V CC , auxiliary power supply V AUX1 、V AUX2 The windings 305A, 305B, and 305C all belong to the transformer 302 and are inductively coupled to each other. The number of turns of the winding 305A is N. 305A Maximum number of turns N of winding 305B 305B Next, the number of coil turns N of winding 305C 305C In the following embodiments, the coil turn ratio N between the windings 305A, 305B, and 305C is 305A :N 305B :N 305C Equal to 3:2:1.

[0095] The USB PD controller 301 has a power management module 310. The power management module 310 can select the output power V CC , auxiliary power supply V AUX1 、V AUX2 One of them is used as the input power supply, providing power to establish the operating power supply V DD , powering the logic circuit 312.

[0096] Figure 9The power management module 310 is illustrated. The power management module 310 is similar to the power management module 210C, and the same or similar parts can be referred to the previous description. The power management module 310 has linear regulators 314A, 314B and 314C. The linear regulators 314A, 314B and 314C are configured to generate an operating voltage V CC , an auxiliary voltage V AUX1 , and a voltage V AUX2 as input voltages, respectively, to generate an operating voltage V DD . The linear regulators 314A, 314B and 314C are configured to regulate the operating voltage V DD at 4.7V, 4.85V and 5V, respectively. The operating voltage V DD between 4.7V and 5V can allow the logic circuit 312 to operate normally.

[0097] The power management module 310 can be considered to select one of the output voltage V DD , the auxiliary voltage V CC , and the voltage V AUX1 as an input voltage to provide power to maintain the operating voltage V AUX2 , depending on the operating voltage V DD . When the operating voltage V DD is 5V, the linear regulators 314A and 314B are off, and the linear regulator 314C draws current from the auxiliary voltage V AUX2 to supply the operating voltage V DD . When the operating voltage V DD is 4.85V, the linear regulator 314A is off, and the voltage V AUX2 generated by the winding 305B is not sufficient to boost the operating voltage V DD to 5V, so the linear regulator 314B draws current from the auxiliary voltage V AUX1 to supply the operating voltage V DD . When the operating voltage V DD is 4.7V, neither the auxiliary voltage V AUX1 nor the voltage V AUX2 is sufficient to boost the operating voltage V DD to 4.85V, so the linear regulator 314C draws current from the output voltage V CC to supply the operating voltage V DD .

[0098] The above description is only some preferred embodiments of the present application, and any equivalent changes and modifications made according to the claims of the present application shall be included in the scope of the present application.

Claims

1. A power supply system, comprising: a first rectifier filter connected to a first winding for providing an output power; a second rectifier filter connected to an auxiliary winding for providing an auxiliary power, wherein the auxiliary winding is inductively coupled to the first winding, and the first winding has a first winding number of turns greater than an auxiliary winding number of turns of the auxiliary winding; and a power management module connected to the auxiliary power and the output power for selecting or not selecting the output power as an input power according to one of an operating power and the output power, wherein the input power is used to power the power management module to generate and regulate the operating power.

2. The power supply system of claim 1, wherein, The power management module comprises: a detection circuit for comparing the output power and a preset voltage; a linear regulator for generating and regulating the operating power; and a selection switch connected between the output power and the linear regulator; wherein when the output power is higher than the preset voltage, the detection circuit turns off the selection switch and does not select the output power as the input power.

3. The power supply system of claim 2, wherein, The power management module comprises: a diode connected between the auxiliary power and the linear regulator; wherein the auxiliary power can pass through the diode and be used as the input power to power the linear regulator.

4. The power supply system of claim 1, wherein, The power management module comprises: a first linear regulator powered by the output power for generating and regulating the operating power at a first preset voltage; and a second linear regulator powered by the auxiliary power for generating and regulating the operating power at a second preset voltage; wherein the second preset voltage is higher than the first preset voltage. The first linear regulator comprises a first operational amplifier, the second linear regulator comprises a second operational amplifier, and the power management module comprises three resistors connected in series between the operating power and a ground line, the three resistors providing two ends connected to the first and second operational amplifiers, respectively.

5. The power supply system of claim 4, wherein, 6. A power supply method for generating an operating power, comprising: the first winding has a first winding number of turns greater than an auxiliary winding number of turns of the auxiliary winding; A first winding is provided that is inductively coupled to the phase and an auxiliary winding, wherein rectifying a first winding current of the first winding to generate an output power; rectifying an auxiliary winding current of the auxiliary winding to generate an auxiliary power; selecting or not selecting the output power as an input power according to one of the operating power and the output power; and using the input power to provide power to establish and regulate the operating power on a power line.

7. The power supply method of claim 6, further comprising: comparing the output power and a preset voltage; when the output power is higher than the preset voltage, not selecting the output power as the input power and selecting the auxiliary power as the input power; and when the output power is lower than the preset voltage, selecting the output power as the input power.

8. The power supply method of claim 6, further comprising: linearly regulating the operating power at a first preset voltage using the output power as power; and linearly regulating the operating power at a second preset voltage using the auxiliary power as power; the second preset voltage is higher than the first preset voltage.

9. A power supply system for generating an operating power, comprising: wherein, ​ ​ a first rectifier filter connected to the first winding for providing an output power supply; a second rectifier filter connected to the auxiliary winding for providing an auxiliary power supply, wherein the auxiliary winding is inductively coupled to the first winding, and the first winding has a first winding turn number greater than an auxiliary winding turn number of the auxiliary winding; and a power management module comprising: a first linear voltage regulator connected between the auxiliary power supply and the output power supply for regulating the auxiliary power supply at a first preset voltage; and a second linear voltage regulator connected between the auxiliary power supply and the operating power supply for regulating the operating power supply at a second preset voltage. wherein the first preset voltage is greater than the second preset voltage.

10. The power supply system of claim 9, wherein, The first linear voltage regulator comprises a first operational amplifier and a first power switch connected between the auxiliary power supply and the output power supply and controlled by the first operational amplifier, and the second linear voltage regulator comprises a second operational amplifier and a second power switch connected between the auxiliary power supply and the operating power supply and controlled by the second operational amplifier.

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