Power supply circuit based on PFC and AHB and used for charger

Abstract

The utility model discloses a power supply circuit based on PFC and AHB and used for a charger, comprising a power supply interface AC, the front side of the power supply interface AC is provided with a PFC boost circuit, the right side of the PFC boost circuit is provided with an AHB control circuit, and a differential common mode filter circuit, a full bridge rectifier circuit and an II type filter circuit are arranged between the power supply interface AC and the PFC boost circuit from front to back in sequence. An isolation transformation circuit is arranged between the PFC booster circuit and the AHB control circuit, a synchronous rectification circuit and an optocoupler feedback circuit are arranged on the right side of the AHB control circuit, the output end of the power interface AC is electrically connected with the input end of the differential common mode filter circuit, and the output end of the differential common mode filter circuit is electrically connected with the input end of the full-bridge rectification circuit. And the output end of the full-bridge rectifier circuit is electrically connected with the input end of the II-type filter circuit. According to the utility model, the problem of low charging efficiency of a traditional charger in the prior art is solved. The charging device has the advantages of high charging efficiency, good charging stability and the like.

Description

Technical Field

[0001] This utility model relates to the field of charger equipment, and more specifically, to a power supply circuit based on PFC and AHB for use in a charger. Background Technology

[0002] With the continuous development of electronic products, charging equipment is moving towards miniaturization, flatness, and multi-functionality. Traditional charging equipment is bulky, has low charging efficiency, generates a lot of heat, and has limited functions, which cannot meet the needs of various customers.

[0003] Currently, a miniaturized charging power transformer, publication number CN217239235U, is disclosed on the Chinese patent website. It includes a magnetic core and a frame, with the magnetic core and frame symmetrically connected at their upper and lower ends. The magnetic core comprises a groove, a central post, and soft epoxy resin. Compared with traditional technologies, this invention improves the magnetic core structure, ensuring the required cross-sectional area while significantly reducing the product height, thus achieving miniaturization. The frame design is also improved, simplifying the manufacturing process and reducing costs while ensuring a safety distance >8.0mm between the primary and secondary windings and a product height <18mm.

[0004] The miniaturized charging power transformer in the aforementioned patent has the advantage of small size, but its circuit architecture does not adopt the AHB topology, resulting in low charging efficiency. Utility Model Content

[0005] In order to overcome the problem of low charging efficiency of traditional chargers in the prior art, this utility model provides a power supply circuit based on PFC and AHB for chargers, which has the advantage of improving the charging efficiency of chargers.

[0006] This utility model discloses a power supply circuit for a charger based on PFC and AHB, including a power interface AC. A PFC boost circuit is located at the front of the power interface AC, and an AHB control circuit is located to the right of the PFC boost circuit. From front to back, a differential common-mode filter circuit, a full-bridge rectifier circuit, and a Type II filter circuit are sequentially arranged between the power interface AC and the PFC boost circuit. An isolation transformer circuit is located between the PFC boost circuit and the AHB control circuit. A synchronous rectifier circuit and an optocoupler feedback circuit are located to the right of the AHB control circuit. The output terminal of the power interface AC is electrically connected to the input terminal of the differential common-mode filter circuit, and the output terminal of the differential common-mode filter circuit is connected to the input terminal of the full-bridge rectifier circuit. The input terminals are electrically connected as follows: the output terminal of the full-bridge rectifier circuit is electrically connected to the input terminal of the type II filter circuit; the output terminal of the type II filter circuit is electrically connected to the input terminal of the PFC boost circuit; the output terminal of the PFC boost circuit is electrically connected to the input terminal of the isolation transformer circuit; the output terminal of the isolation transformer circuit is electrically connected to both the power input terminal of the AHB control circuit and the input terminal of the full-bridge rectifier circuit; the signal transmission terminal of the AHB control circuit is electrically connected to the signal input terminal of the isolation transformer circuit; the output terminal of the full-bridge rectifier circuit is electrically connected to the input terminal of the optocoupler feedback circuit; and the output terminal of the optocoupler feedback circuit is electrically connected to the signal input terminal of the AHB control circuit.

[0007] Preferably, the differential-common-mode filter circuit includes a fuse F1, transformers LF1 and LF2, capacitors CX1, CY1, CY2, and CY3, diodes D4 and D5, and resistor R24. One end of fuse F1 is electrically connected to pin 1 of the power interface AC, and the other end of fuse F1 is electrically connected to pin 1 of transformer LF1. Pin 2 of transformer LF1 is electrically connected to pin 2 of the power interface AC. One end of capacitor CX1 is electrically connected to pin 4 of transformer LF1 and pin 1 of transformer LF2, and the other end of capacitor CX1 is electrically connected to pin 4 of transformer LF1 and pin 1 of transformer LF2, respectively. Pin 3 of the capacitor is electrically connected to pin 2 of the transformer LF2. Pin 3 of the transformer LF2 is electrically connected to the anode of diode D5 and the full-bridge rectifier circuit. The cathode of diode D5 is electrically connected to one end of resistor R24 ​​and the cathode of diode D4. The other end of resistor R24 ​​is electrically connected to the AHB control circuit. The anode of diode D4 is electrically connected to the full-bridge rectifier circuit. The other end of capacitor CX1 is electrically connected to one end of CY3. The other end of CY3 is electrically connected to one end of CY2 and one end of CY1. The other end of CY3 is connected to signal ground, and the other end of CY2 is grounded.

[0008] Preferably, the full-bridge rectifier circuit includes rectifier bridge BD1 and rectifier bridge BD2. Pin 1 of rectifier bridge BD1 is electrically connected to the positive terminal of diode D4, pin 4 of transformer LF2, and pin 3 of rectifier bridge BD1. Pin 1 of rectifier bridge BD2 is electrically connected to the positive terminal of diode D5, pin 3 of transformer LF2, and pin 3 of rectifier bridge BD2. Pins 2 and 4 of rectifier bridge BD1, pins 2 and 4 of rectifier bridge BD2 are electrically connected to a type II filter circuit.

[0009] Preferably, the type II filter circuit includes capacitors CB1, CB2, CB4, and inductor L1. One end of inductor L1 is electrically connected to pin 4 of rectifier bridge BD1, pin 4 of rectifier bridge BD2, and one end of capacitor CB2. The other end of inductor L1 is electrically connected to one end of capacitor CB1 and one end of capacitor CB4. The other ends of capacitors CB1, CB2, and CB4, pin 2 of rectifier bridge BD1, and pin 2 of rectifier bridge BD2 are electrically connected. The other end of capacitor CB1 is grounded.

[0010] Preferably, the PFC boost circuit includes chip U4, MOSFET Q1, inductor T1, inductor L1, inductor BEAD1, diode D1, diode U1, diode D3, capacitor C5, capacitor C6, capacitor C7, capacitor C8, capacitor C10, capacitor C11, capacitor C12, capacitor C13, resistors R1, resistor R2, resistor R5, resistor R6, resistor R8, resistor R9, resistor R12, resistor R13, resistor R15, resistor R16, resistor R18, resistor R19, resistor R20, resistor R21, and resistor R22. One end of inductor T1 is electrically connected to the positive terminal of diode D1 and one end of capacitor CB4, respectively. The negative terminal of diode D1 is connected to the... The negative terminal of diode U1 is electrically connected to one end of resistor R1. The positive terminal of diode U1 is electrically connected to the other end of inductor T1, one end of capacitor C5, one end of resistor R2, and one end of inductor L2. The other end of inductor L2 is electrically connected to pin 2 of MOSFET Q1. The other end of resistor R2 is electrically connected to one end of resistor R5. The other end of capacitor C5 is electrically connected to the other end of resistor R5, one end of resistor R15, one end of capacitor C8, and one end of resistor R18. The other end of resistor R15 is electrically connected to the other end of capacitor C8, one end of resistor R19, one end of resistor R20, one end of resistor R21, one end of resistor R12, and pin 3 of MOSFET Q1. Electrically connected, pin 1 of the MOSFET Q1 is electrically connected to one end of the inductor BEAD1. The other end of the inductor BEAD1 is electrically connected to one end of resistor R8, the other end of resistor R12, and one end of resistor R13. The other end of resistor R8 is electrically connected to the anode of diode D3. The cathode of diode D3 is electrically connected to pin 5 of chip U4 and the other end of resistor R13. Pin 2 of chip U4 is electrically connected to the other end of resistor R18 and one end of capacitor C13. The other end of capacitor C13 is electrically connected to the other ends of resistors R19, R20, R21, and R22. The other end of resistor R21 is grounded. The other end of resistor R22 is electrically connected to one end of resistor R9, one end of capacitor C12, and pin 1 of chip U4. The other end of resistor R9 is electrically connected to one end of resistor R6. The other end of resistor R6 is electrically connected to the other end of resistor R1. The other end of capacitor C12 is electrically connected to one end of capacitors C11, C10, C7, and C6, and pin 4 of chip U4. Pin 4 of chip U4 is grounded. The other end of capacitor C11 is electrically connected to one end of resistor R16. The other end of resistor R16 is electrically connected to the other end of capacitor C10 and pin 6 of chip U4.The other end of capacitor C7 is electrically connected to the other end of capacitor C6 and pin 3 of chip U4.

[0011] Preferably, the AHB control circuit includes chip U6, polarized capacitors EC5 and EC6, capacitor CB3, capacitors C14, C15, and C16, transformer T2, resistors RS1, RS2, RS3, R7, R25, R27, R26, R28, R29, R30, and R31, diodes D6, D7, and D8, Zener diode D9, and MOSFET Q3. Pin 1 of chip U6 is electrically connected to one end of resistors RS1, RS2, and RS3, respectively. One end of resistor RS1 is connected to protective ground. Pin 2 of chip U6 is connected to resistor RS3... The other end of the capacitor is electrically connected to the other end of resistor R1, resistor RS2, and resistor RS1. The negative terminal of the polarized capacitor EC1 is grounded. Pin 3 of chip U6 is electrically connected to one end of resistor R30 and one end of resistor R31, respectively. Pin 4 of chip U6 is electrically connected to one end of capacitor C16. The other end of capacitor C16 is electrically connected to one end of capacitor C15, pin 6 of chip U6, and pin 12 of chip U6, respectively. Pin 12 of chip U6 is connected to protective ground. Pin 5 of chip U6 is electrically connected to the other end of capacitor C15. The other end of capacitor C15 is electrically connected to one end of resistor R26, the positive terminal of polarized capacitor EC6, the negative terminal of diode D7, and the terminal of MOSFET Q3, respectively. Pin 1 of the resistor R26 is electrically connected to one end of resistor R25. The other end of resistor R26 is electrically connected to pin 3 of chip U4. The other end of resistor R25 is electrically connected to the anode of diode D6. The other end of resistor R24 ​​is electrically connected to pin 7 of chip U6. The cathode of diode D6 is electrically connected to pin 8 of chip U6 and one end of capacitor C14. The other end of capacitor C14 is electrically connected to pin 9 and pin 11 of chip U6, one end of resistor R7, and one end of capacitor CB3. The other end of resistor R7 and the other end of capacitor CB3 are electrically connected. Pin 2 of MOSFET Q3 is electrically connected to one end of resistor R29 and the anode of polarized capacitor EC5. The cathode of diode D8 is electrically connected to the cathode of MOSFET Q3. Pin 3 of MOSFET Q3 is electrically connected to the cathode of Zener diode D9 and the other end of resistor R29. The anode of Zener diode D9 is electrically connected to the cathode of polarized capacitor EC6, the cathode of polarized capacitor EC5, the other end of resistor R31, and pin 8 of transformer T2. The other end of resistor R31 is connected to protective ground. The anode of diode D8 is electrically connected to one end of resistor R28. The other end of resistor R28 is electrically connected to the other end of resistor R30 and pin 2 of transformer T2. Pin 1 of transformer T2 is electrically connected to one end of resistor R27. The other end of resistor R27 is electrically connected to the anode of diode D7.

[0012] Preferably, the isolation transformer circuit includes polarized capacitors EC1, EC2, EC3, and EC4, capacitor C1, capacitor C3, inductor L3, and inductor L4. One end of capacitor C3 is electrically connected to one end of resistor R1, the positive terminals of polarized capacitors EC1, EC2, EC3, and EC4, one end of capacitor C1, one end of inductor L4, one end of inductor L3, and the 4-pin connector of transformer T2. The 4-pin connector of transformer T2 is... The other end of capacitor CY1 is connected to Vout, the other end of capacitor C3 is grounded, the negative terminals of polarized capacitors EC1, EC2, EC3, and EC4, the other end of capacitor C1, and the other end of resistor RS1 are electrically connected, the negative terminal of polarized capacitor EC1 is grounded, the other end of inductor L4 is electrically connected to the other end of inductor L3 and pin 10 of chip U6, and pin 6 of transformer T2 is electrically connected to the other end of capacitor CB3.

[0013] Preferably, the synchronous rectification circuit includes a Zener diode D2, a diode DK, a capacitor C4, a polarized capacitor C7, a polarized capacitor C8, a polarized capacitor C11, and a polarized capacitor C12. Pin 10 of the transformer T2 is electrically connected to the positive terminals of polarized capacitors EC7, EC8, EC11, and EC12, respectively. Pin 11 of the transformer T2 is connected to the negative terminal of diode DK, one end of resistor R4, one end of resistor R3, and... The negative terminal of Zener diode D2 is electrically connected. The positive terminal of Zener diode D2 is electrically connected to one end of capacitor C4, the positive terminal of diode DK, the negative terminals of polarized capacitors EC7, EC8, EC11, and EC12. The other end of resistor R4 is electrically connected to the other end of resistor R3 and the other end of capacitor C4. The negative terminal of polarized capacitor EC12 is connected to signal ground, and the positive terminal of polarized capacitor EC11 outputs VIN.

[0014] Preferably, the optocoupler feedback circuit includes an optocoupler U5, a controllable precision voltage regulator Q2, resistors R10, R11, R14, R17, and R23. Pin 1 of the optocoupler U5 is electrically connected to one end of resistors R10 and R11, respectively. The other end of resistor R10 is electrically connected to one end of resistor R14 and the positive terminal of polarized capacitor EC12, respectively. Pin 2 of the optocoupler U5 is electrically connected to the other end of resistor R11, one end of capacitor C9, and pin 1 of the controllable precision voltage regulator Q2, respectively. The other end of capacitor C9 is electrically connected to one end of resistor R17, and the other end of resistor R17 is electrically connected to the other end of resistor R14, pin 3 of the controllable precision voltage regulator Q2, and one end of resistor R13, respectively. Pin 2 of the controllable precision voltage regulator Q2 is electrically connected to the other end of resistor R13, and pin 2 of the controllable precision voltage regulator Q2 is connected to signal ground.

[0015] This invention utilizes GaN semiconductor technology and an asymmetric half-bridge (AHB) topology, enabling the charger to be more than 50% smaller than power supplies developed using traditional MOS technology, while improving efficiency by approximately 3%. A pre-amplified PFC power factor correction circuit further enhances input power utilization efficiency and meets certification requirements. This invention employs the PowerDeliver (PD) protocol, which supports communication protocols such as PPS, PD, QC, AFC, FCP, SCP, and PE, satisfying the charging requirements of most mobile phones and devices.

[0016] The working principle of this utility model:

[0017] Connect the AC power interface to a three-phase power supply. After connection, the three-phase power is sequentially filtered and rectified by a differential-common-mode filter circuit, a full-bridge rectifier circuit, and a Π-type filter circuit. Then, it is boosted to approximately 300V by a PFC boost circuit before being input to the AHB control circuit. The power device switch built into chip U6 controls the electromagnetic energy conversion of the isolation transformer, providing a safe and stable voltage to the secondary side of transformer T2. The synchronous rectification control circuit of chip U2 and the optocoupler feedback circuit further stabilize the DC output and improve the overall system efficiency.

[0018] This invention has the following advantages: high charging efficiency and good charging stability. Attached Figure Description

[0019] Appendix Figure 1 This is the circuit schematic diagram of this utility model.

[0020] Appendix Figure 2 This is a schematic diagram of the differential common-mode filter circuit of this utility model.

[0021] Appendix Figure 3This is a schematic diagram of the full-bridge rectifier circuit of this utility model.

[0022] Appendix Figure 4 This is a schematic diagram of the Type II filter circuit of this utility model.

[0023] Appendix Figure 5 This is a schematic diagram of the PFC boost circuit of this utility model.

[0024] Appendix Figure 6 This is a schematic diagram of the AHB control circuit of this utility model.

[0025] Appendix Figure 7 This is a schematic diagram of the synchronous rectifier circuit of this utility model.

[0026] Appendix Figure 8 This is a schematic diagram of the optocoupler feedback circuit of this utility model. Detailed Implementation

[0027] The technical solution of this utility model will be further described in detail below through embodiments and in conjunction with the accompanying drawings.

[0028] Example: According to the appendix Figure 1 Appendix Figure 2 Appendix Figure 3 Appendix Figure 4 Appendix Figure 5 Appendix Figure 6 Appendix Figure 7 and attached Figure 8Further describing this utility model, this example provides a power supply circuit for a charger based on PFC and AHB, including a power interface AC. A PFC boost circuit is located at the front of the power interface AC, and an AHB control circuit is located to the right of the PFC boost circuit. From front to back, a differential / common-mode filter circuit, a full-bridge rectifier circuit, and a Type II filter circuit are sequentially arranged between the power interface AC and the PFC boost circuit. An isolation transformer circuit is located between the PFC boost circuit and the AHB control circuit. A synchronous rectifier circuit and an optocoupler feedback circuit are located to the right of the AHB control circuit. The output terminal of the power interface AC is electrically connected to the input terminal of the differential / common-mode filter circuit, and the output terminal of the differential / common-mode filter circuit is electrically connected to the input terminal of the full-bridge rectifier circuit. The input terminal of the bridge rectifier circuit is electrically connected; the output terminal of the full-bridge rectifier circuit is electrically connected to the input terminal of the type II filter circuit; the output terminal of the type II filter circuit is electrically connected to the input terminal of the PFC boost circuit; the output terminal of the PFC boost circuit is electrically connected to the input terminal of the isolation transformer circuit; the output terminal of the isolation transformer circuit is electrically connected to both the power input terminal of the AHB control circuit and the input terminal of the full-bridge rectifier circuit; the signal transmission terminal of the AHB control circuit is electrically connected to the signal input terminal of the isolation transformer circuit; the output terminal of the full-bridge rectifier circuit is electrically connected to the input terminal of the optocoupler feedback circuit; and the output terminal of the optocoupler feedback circuit is electrically connected to the signal input terminal of the AHB control circuit.

[0029] The differential-common-mode filter circuit includes a fuse F1, transformers LF1 and LF2, capacitors CX1, CY1, CY2, and CY3, diodes D4 and D5, and resistor R24. One end of fuse F1 is electrically connected to pin 1 of the power interface AC, and the other end of fuse F1 is electrically connected to pin 1 of transformer LF1. Pin 2 of transformer LF1 is electrically connected to pin 2 of the power interface AC. One end of capacitor CX1 is electrically connected to pin 4 of transformer LF1 and pin 1 of transformer LF2, and the other end of capacitor CX1 is electrically connected to pin 3 of transformer LF1. The pins of the transformer LF2 are electrically connected to pin 2. Pin 3 of the transformer LF2 is electrically connected to the anode of diode D5 and the full-bridge rectifier circuit. The cathode of diode D5 is electrically connected to one end of resistor R24 ​​and the cathode of diode D4. The other end of resistor R24 ​​is electrically connected to the AHB control circuit. The anode of diode D4 is electrically connected to the full-bridge rectifier circuit. The other end of capacitor CX1 is electrically connected to one end of CY3. The other end of CY3 is electrically connected to one end of CY2 and one end of CY1. The other end of CY3 is connected to signal ground, and the other end of CY2 is grounded.

[0030] The full-bridge rectifier circuit includes rectifier bridge BD1 and rectifier bridge BD2. Pin 1 of rectifier bridge BD1 is electrically connected to the positive terminal of diode D4, pin 4 of transformer LF2, and pin 3 of rectifier bridge BD1. Pin 1 of rectifier bridge BD2 is electrically connected to the positive terminal of diode D5, pin 3 of transformer LF2, and pin 3 of rectifier bridge BD2. Pins 2 and 4 of rectifier bridge BD1, pins 2 and 4 of rectifier bridge BD2 are electrically connected to a type II filter circuit.

[0031] The type II filter circuit includes capacitors CB1, CB2, and CB4, and inductor L1. One end of inductor L1 is electrically connected to pin 4 of rectifier bridge BD1, pin 4 of rectifier bridge BD2, and one end of capacitor CB2. The other end of inductor L1 is electrically connected to one end of capacitor CB1 and one end of capacitor CB4. The other ends of capacitors CB1, CB2, and CB4, pin 2 of rectifier bridge BD1, and pin 2 of rectifier bridge BD2 are electrically connected. The other end of capacitor CB1 is grounded.

[0032] The PFC boost circuit includes chip U4, MOSFET Q1, inductor T1, inductor L1, inductor BEAD1, diode D1, diode U1, diode D3, capacitors C5, C6, C7, C8, C10, C11, C12, C13, resistors R1, R2, R5, R6, R8, R9, R12, R13, R15, R16, R18, R19, R20, R21, and R22. One end of inductor T1 is electrically connected to the anode of diode D1 and one end of capacitor CB4, respectively. The cathode of diode D1 is connected to diode U1. The negative terminal of diode U1 is electrically connected to one end of resistor R1. The positive terminal of diode U1 is electrically connected to the other end of inductor T1, one end of capacitor C5, one end of resistor R2, and one end of inductor L2. The other end of inductor L2 is electrically connected to pin 2 of MOSFET Q1. The other end of resistor R2 is electrically connected to one end of resistor R5. The other end of capacitor C5 is electrically connected to the other end of resistor R5, one end of resistor R15, one end of capacitor C8, and one end of resistor R18. The other end of resistor R15 is electrically connected to the other end of capacitor C8, one end of resistor R19, one end of resistor R20, one end of resistor R21, one end of resistor R12, and pin 3 of MOSFET Q1. The connections are as follows: pin 1 of the MOSFET Q1 is electrically connected to one end of the inductor BEAD1; the other end of the inductor BEAD1 is electrically connected to one end of resistor R8, the other end of resistor R12, and one end of resistor R13; the other end of resistor R8 is electrically connected to the anode of diode D3; the cathode of diode D3 is electrically connected to pin 5 of chip U4 and the other end of resistor R13; pin 2 of chip U4 is electrically connected to the other end of resistor R18 and one end of capacitor C13; the other end of capacitor C13 is electrically connected to the other ends of resistors R19, R20, R21, and R22; and the resistor R... The other end of resistor R21 is grounded. The other end of resistor R22 is electrically connected to one end of resistor R9, one end of capacitor C12, and pin 1 of chip U4. The other end of resistor R9 is electrically connected to one end of resistor R6. The other end of resistor R6 is electrically connected to the other end of resistor R1. The other end of capacitor C12 is electrically connected to one end of capacitor C11, one end of capacitor C10, one end of capacitor C7, one end of capacitor C6, and pin 4 of chip U4. Pin 4 of chip U4 is grounded. The other end of capacitor C11 is electrically connected to one end of resistor R16. The other end of resistor R16 is electrically connected to the other end of capacitor C10 and pin 6 of chip U4.The other end of capacitor C7 is electrically connected to the other end of capacitor C6 and pin 3 of chip U4.

[0033] The AHB control circuit includes chip U6, polarized capacitors EC5 and EC6, capacitor CB3, capacitors C14, C15, and C16, transformer T2, resistors RS1, RS2, RS3, R7, R25, R27, R26, R28, R29, R30, and R31, diodes D6, D7, and D8, Zener diode D9, and MOSFET Q3. Pin 1 of chip U6 is electrically connected to one end of resistors RS1, RS2, and RS3, respectively. One end of resistor RS1 is connected to protective ground. Pin 2 of chip U6 is connected to the other end of resistor RS3. The other ends of resistor RS2 and resistor RS1 are electrically connected. The negative terminal of the polarized capacitor EC1 is grounded. Pin 3 of chip U6 is electrically connected to one end of resistor R30 and one end of resistor R31, respectively. Pin 4 of chip U6 is electrically connected to one end of capacitor C16. The other end of capacitor C16 is electrically connected to one end of capacitor C15, pin 6 of chip U6, and pin 12 of chip U6, respectively. Pin 12 of chip U6 is connected to protective ground. Pin 5 of chip U6 is electrically connected to the other end of capacitor C15. The other end of capacitor C15 is electrically connected to one end of resistor R26, the positive terminal of polarized capacitor EC6, the negative terminal of diode D7, and pin 1 of MOSFET Q3, respectively. One end of resistor R25 is electrically connected to pin 3 of chip U4. The other end of resistor R25 is electrically connected to the anode of diode D6. The other end of resistor R24 ​​is electrically connected to pin 7 of chip U6. The cathode of diode D6 is electrically connected to pin 8 of chip U6 and one end of capacitor C14. The other end of capacitor C14 is electrically connected to pin 9 and pin 11 of chip U6, one end of resistor R7, and one end of capacitor CB3. The other end of resistor R7 and the other end of capacitor CB3 are electrically connected. Pin 2 of MOSFET Q3 is electrically connected to one end of resistor R29 and the anode of polarized capacitor EC5. The cathode of diode D8 is electrically connected to the MOSFET Q3. Pin 3 of the MOSFET Q3 is electrically connected to the cathode of Zener diode D9 and the other end of resistor R29. The anode of Zener diode D9 is electrically connected to the cathode of polarized capacitor EC6, the cathode of polarized capacitor EC5, the other end of resistor R31, and pin 8 of transformer T2. The other end of resistor R31 is connected to protective ground. The anode of diode D8 is electrically connected to one end of resistor R28. The other end of resistor R28 is electrically connected to the other end of resistor R30 and pin 2 of transformer T2. Pin 1 of transformer T2 is electrically connected to one end of resistor R27. The other end of resistor R27 is electrically connected to the anode of diode D7.

[0034] The isolation transformer circuit includes polarized capacitors EC1, EC2, EC3, EC4, capacitor C1, capacitor C3, inductor L3, and inductor L4. One end of capacitor C3 is electrically connected to one end of resistor R1, the positive terminals of polarized capacitors EC1, EC2, EC3, and EC4, one end of capacitor C1, one end of inductor L4, one end of inductor L3, and pin 4 of transformer T2. The four pins of transformer T2 output Vo. The other end of capacitor CY1 is connected to Vout, the other end of capacitor C3 is grounded, the negative terminals of polarized capacitors EC1, EC2, EC3, and EC4, the other end of capacitor C1, and the other end of resistor RS1 are electrically connected, the negative terminal of polarized capacitor EC1 is grounded, the other end of inductor L4 is electrically connected to the other end of inductor L3 and pin 10 of chip U6, and pin 6 of transformer T2 is electrically connected to the other end of capacitor CB3.

[0035] The synchronous rectification circuit includes a Zener diode D2, a diode DK, a capacitor C4, a polarized capacitor C7, a polarized capacitor C8, a polarized capacitor C11, and a polarized capacitor C12. Pin 10 of the transformer T2 is electrically connected to the positive terminals of polarized capacitors EC7, EC8, EC11, and EC12, respectively. Pin 11 of the transformer T2 is connected to the negative terminal of diode DK, one end of resistor R4, one end of resistor R3, and the Zener diode... The negative terminal of diode D2 is electrically connected. The positive terminal of the Zener diode D2 is electrically connected to one end of capacitor C4, the positive terminal of diode DK, the negative terminals of polarized capacitors EC7, EC8, EC11, and EC12. The other end of resistor R4 is electrically connected to the other end of resistor R3 and the other end of capacitor C4. The negative terminal of polarized capacitor EC12 is connected to signal ground, and the positive terminal of polarized capacitor EC11 outputs VIN.

[0036] The optocoupler feedback circuit includes an optocoupler U5, a controllable precision voltage regulator Q2, resistors R10, R11, R14, R17, and R23. Pin 1 of the optocoupler U5 is electrically connected to one end of resistors R10 and R11. The other end of resistor R10 is electrically connected to one end of resistor R14 and the positive terminal of polarized capacitor EC12. Pin 2 of the optocoupler U5 is electrically connected to the other end of resistor R11, one end of capacitor C9, and pin 1 of the controllable precision voltage regulator Q2. The other end of capacitor C9 is electrically connected to one end of resistor R17. The other end of resistor R17 is electrically connected to the other end of resistor R14, pin 3 of the controllable precision voltage regulator Q2, and one end of resistor R13. Pin 2 of the controllable precision voltage regulator Q2 is electrically connected to the other end of resistor R13. Pin 2 of the controllable precision voltage regulator Q2 is connected to signal ground.

[0037] The above description is only a specific embodiment of the present utility model, but the structural features of the present utility model are not limited thereto. Any changes or modifications made by those skilled in the art within the scope of the present utility model are covered by the patent scope of the present utility model.

Claims

1. A power supply circuit based on PFC and AHB for a charger, including a power interface AC, characterized in that, The power interface AC has a PFC boost circuit on its front side, and an AHB control circuit on its right side. Between the power interface AC and the PFC boost circuit, from front to back, are a differential common-mode filter circuit, a full-bridge rectifier circuit, and a Type II filter circuit. An isolation transformer circuit is located between the PFC boost circuit and the AHB control circuit. To the right of the AHB control circuit are a synchronous rectifier circuit and an optocoupler feedback circuit. The output of the power interface AC is electrically connected to the input of the differential common-mode filter circuit, and the output of the differential common-mode filter circuit is electrically connected to the input of the full-bridge rectifier circuit. The output of the full-bridge rectifier circuit... The output terminal is electrically connected to the input terminal of the Type II filter circuit. The output terminal of the Type II filter circuit is electrically connected to the input terminal of the PFC boost circuit. The output terminal of the PFC boost circuit is electrically connected to the input terminal of the isolation transformer circuit. The output terminal of the isolation transformer circuit is electrically connected to the power input terminal of the AHB control circuit and the input terminal of the full-bridge rectifier circuit, respectively. The signal transmission terminal of the AHB control circuit is electrically connected to the signal input terminal of the isolation transformer circuit. The output terminal of the full-bridge rectifier circuit is electrically connected to the input terminal of the optocoupler feedback circuit. The output terminal of the optocoupler feedback circuit is electrically connected to the signal input terminal of the AHB control circuit.

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