Switching power supply circuit of totem bridgeless PFC

Abstract

The utility model provides a totem bridgeless PFC switching power supply circuit. The totem bridgeless PFC switching power supply circuit comprises a filter circuit, a surge circuit, a commercial power zero-cross detection circuit, a commercial power low-frequency synchronous rectification circuit, a PFC current detection circuit, a PFC boost circuit, a PFC oscillation control circuit and a high-frequency synchronous rectification filter circuit. The filter circuit, the PFC current detection circuit, the PFC booster circuit and the high-frequency synchronous rectification filter circuit are connected in sequence; the filter circuit is also connected with the power supply input end, the surge circuit and the mains supply zero-cross detection circuit; the PFC booster circuit is also connected with the PFC oscillation control circuit; the mains supply zero-cross detection circuit is connected with the PFC oscillation control circuit through the mains supply low-frequency synchronous rectification circuit, the high-frequency synchronous rectification filter circuit is connected with the output end, the PFC boost circuit is provided with a high-side switching tube and a low-side switching tube, and the PFC boost circuit is provided with the high-side switching tube and the low-side switching tube. Through cooperative work of the high-side switching tube and the low-side switching tube, the efficiency and reliability of the circuit are improved, and the voltage output by the circuit is stable.

Description

Technical Field

[0001] This utility model relates to the field of switching power supply technology, specifically to a totem-based bridgeless PFC switching power supply circuit. Background Technology

[0002] In power electronic equipment, bridgeless PFC (Power Factor Correction) circuits are mostly used for regulation. Bridgeless PFC circuits are widely used because they have advantages such as simple circuit structure, low conduction loss and high conversion efficiency.

[0003] In bridgeless PFC circuits, it is generally necessary to acquire AC input voltage and output voltage signals, and generate duty cycle control signals based on these signals to achieve PFC functionality. However, existing methods for acquiring AC input voltage signals, such as using high-linearity optocouplers, often suffer from problems such as complex sampling circuits and circuit instability. Utility Model Content

[0004] In view of this, the purpose of this utility model is to provide a totem-type bridgeless PFC switching power supply circuit, which sets up a PFC boost circuit with high-side switching transistors and low-side switching transistors. By having the high-side switching transistors and low-side switching transistors work together, the efficiency and reliability of the circuit are improved, and the output voltage of the circuit is stabilized.

[0005] To solve the above-mentioned technical problems, the technical solution used in this utility model is as follows:

[0006] The present invention discloses a totem-based bridgeless PFC switching power supply circuit, comprising a filter circuit, a surge circuit, a mains zero-crossing detection circuit, a mains low-frequency synchronous rectification circuit, a PFC current detection circuit, a PFC boost circuit, a PFC oscillation control circuit, and a high-frequency synchronous rectification and filter circuit; the filter circuit, PFC current detection circuit, PFC boost circuit, and high-frequency synchronous rectification and filter circuit are connected in sequence; the filter circuit is also connected to the power input terminal, the surge circuit, and the mains zero-crossing detection circuit; the PFC boost circuit is also connected to the PFC oscillation control circuit; the mains zero-crossing detection circuit is connected to the PFC oscillation control circuit through the mains low-frequency synchronous rectification circuit, and the high-frequency synchronous rectification and filter circuit is connected to the output terminal; the PFC boost circuit has a high-side switch and a low-side switch.

[0007] Preferably, the surge circuit includes impedance Z1, resistor R8, relay JDQ1, resistor R13, resistor R14 and diode D1; the filter circuit includes terminal CN2, magnetic core inductor L1, common mode inductor LF1, common mode inductor LF2, common mode inductor LF3, resistor R40, resistor R41, resistor R59, resistor R60, capacitor C10, capacitor C11, capacitor C12, capacitor C13, capacitor C14 and capacitor C15.

[0008] The two ends of common mode inductor LE3, the two ends of common mode inductor LE2, and the two ends of common mode inductor LE2 are connected in sequence and connected to the power input terminal through terminal CN2. Terminal CN2 is grounded through magnetic core inductor L1.

[0009] Impedance Z1 is connected in parallel across the common-mode inductor LE3, and capacitors C10 and C11 are connected in parallel across the common-mode inductor LF1. One end of impedance Z1 is connected to one end of common-mode inductor LF1, and the other end of impedance Z1 is connected to the other end of common-mode inductor LF1 through resistor R8.

[0010] One end of the common-mode inductor LF1 is connected in series with resistors R60, R40, and the other end of the common-mode inductor LF1; resistors R59 and R60 are connected in parallel, and resistors R41 and R40 are connected in parallel.

[0011] One end of the impedance Z1 is also connected to one end of the capacitor C13. The other end of the capacitor C13 is connected to one end of the capacitor C12, one end of the capacitor C15, and one end of the capacitor C14. The other end of the capacitor C12 is connected to the other end of the impedance Z1. The other end of the capacitor C15 is connected to one end of the common-mode inductor LF2. The other end of the capacitor C14 is connected to the other end of the common-mode inductor LF2. The common-mode inductor LF2 is connected to the mains zero-crossing detection circuit, the PFC current detection circuit, and the mains low-frequency synchronous rectification circuit.

[0012] The resistor R8 is also connected in parallel with the relay JDQ1. One end of the relay JDQ1 is connected to one end of the resistor R14 and the negative terminal of the diode D1. The positive terminal of the diode D1 is connected to the other end of the relay JDQ1. The other end of the resistor R14 and the positive terminal of the diode D1 are also connected to the PFC oscillation control circuit and the PFC current control circuit. The resistor R14 is connected in parallel with the resistor R13.

[0013] Preferably, the PFC current detection circuit includes a first chip circuit, an arithmetic circuit, a second chip circuit, and a conversion circuit; the first chip circuit includes chip U1, resistor R27, capacitor C28, capacitor C29, and capacitor C30.

[0014] One pin of chip U1 is connected to one end of common mode inductor LF2; chip U1 is also connected to the low-frequency synchronous rectified current of the mains power through capacitors C28, C29 and C30 respectively.

[0015] The operational circuit includes operational amplifier U6, MOSFET Q7, operational amplifier U4, capacitors C28, C29, C30, C32, C33, C35, C37, and C38, and resistors R34, R35, R36, R37, R38, R42, R43, R44, R45, R46, R47, R51, R54, R55, R57, R58, and R61.

[0016] One end of resistor R37 is connected to chip U1, and the other end of resistor R37 is connected in series with resistors R54, R55 and R57 in sequence; the other end of resistor R37 is also connected to an inverting input terminal of operational amplifier U6, and resistor R54 is connected to an output terminal of operational amplifier U6.

[0017] One end of resistor R51 is connected to chip U1, and the other end of resistor R51 is connected to resistor R37 through capacitor C35. The other end of resistor R51 is also connected to one end of resistor R61 and a common in-phase input terminal of operational amplifier U6. One output terminal of operational amplifier U6 is also connected to the drain of MOS transistor Q7 through resistor R44.

[0018] One end of resistor R34 is connected to chip U1, and the other end of resistor R34 is connected in series with resistors R42, R38, and R46 in sequence. Resistor R46 is also connected to a capacitor. The other end of resistor R34 is also connected to another non-inverting input terminal of operational amplifier. One end of resistor R36 is connected to chip U1, and the other end of resistor R36 is connected to resistor R34 through capacitor C32. The other end of resistor R36 is also connected to one end of resistor R35 and another inverting input terminal of operational amplifier U6. One end of resistor R38 is also connected to another output terminal of operational amplifier U6, and the other end of resistor R38 is also connected to the drain of MOSFET Q7 through resistor R45. The positive power supply terminal of operational amplifier U6 is connected to one end of resistor R43.

[0019] The other end of the resistor R43 is connected to the capacitor C33 and the positive power supply terminal of the operational amplifier U4. The output terminal of the operational amplifier U4 is connected to the gate of the MOSFET Q7. The drain of the MOSFET Q7 is also connected to the resistor R58 and the capacitor C38.

[0020] The capacitor C33, resistors R35, R46, R57, R61, capacitor C37, negative power supply terminal of operational amplifier U6, resistor R58, capacitor C38, drain of MOSFET Q7, non-inverting input terminal of operational amplifier U4, inverting input terminal of operational amplifier U4, and negative power supply terminal of operational amplifier U4 are all connected to the mains low-frequency synchronous rectification circuit.

[0021] Preferably, the second chip circuit includes resistors R48, R50, and R53, capacitors C31 and C34, and chip U5; the 5V power supply terminal of chip U5 is connected to chip U1 through resistor R27, and the 5V power supply terminal of chip U5 is also connected to one end of capacitor C31; the other pin of chip U5 is connected to one end of resistor R53 and one end of resistor R48; chip U5 is also connected to the mains low-frequency synchronous rectification circuit; one end of resistor R50 is connected to resistor R14, and the other end of resistor R50 is connected to the positive input terminal of operational amplifier U6 and one end of capacitor C34; the other ends of capacitor C34, resistor R53, and resistor R48 are all connected to the mains low-frequency synchronous rectification circuit; the ZA pin of chip U5 is connected to the non-inverting input terminal of operational amplifier U4.

[0022] The conversion circuit includes Zener diodes D3, D4, D5, D9, C12, and D13; capacitors C1, C3, C5, C17, C18, C23, and C26; resistors R22, R26, R31, and R32; power chip IC1; chip U2; magnetic core inductor L2; and terminal block CN1.

[0023] One pin of the power chip IC1 is connected to the negative terminals of diodes D13 and D12, and capacitor C5. The positive terminal of diode D12 is connected to one end of common-mode inductor LF2, and the positive terminal of diode D13 is connected to the other end of common-mode inductor LF2. Another pin of the power chip IC1 is connected to the negative terminal of diode D14, and the positive terminal of diode D14 is connected to the negative terminal of diode D5. The positive terminal of diode D5 is connected to one end of magnetic core inductor L2 and capacitor C13. The other end of magnetic core inductor L2 is connected to one end of capacitor C17, the negative terminal of diode D9, one end of capacitor C18, one end of capacitor C1, and the power chip IC1.

[0024] The other end of capacitor C17 and the negative terminal of diode D5 are connected to the negative terminal of Zener diode D3. The positive terminal of Zener diode D3 is connected to the other end of capacitor C18 and power chip IC1. The other end of capacitor C1 is connected to the negative terminal of diode D4.

[0025] The positive terminal of diode D5 is also connected to resistor R22, and is connected to one end of resistors R14 and R26 through terminal CN1. The other end of resistor R26 is connected to capacitor C23 and one pin of chip U2. The other pin of chip U2 is connected to another pin of chip U2 through series resistors R31 and R32. Resistor R31 is also connected to capacitor C26 and the 5V power supply terminal of chip U5. The positive terminal of diode D9, capacitors C5, C13, C23, R22, R32, and C26 are all connected to the mains low-frequency synchronous rectification circuit.

[0026] Preferably, the high-side switching transistors are MOSFETs Q1 and Q2; the low-side switching transistors are MOSFETs Q3 and Q4; the PFC boost circuit further includes resistors R15, R16, R17, R18, R19, R20, R21, R23, capacitors C19 and C20, inductor T1, diodes D2, D6, D7, D8, D10, and D11.

[0027] The source of the MOSFET Q1 is connected to the low-frequency synchronous rectification circuit of the mains power through diodes D10 and D11 connected in series. The source of the MOSFET Q1 is also connected to the high-frequency synchronous control circuit. The source of the MOSFET Q1 is also connected to one end of capacitor C19. The other end of capacitor C19 is connected to the source of the MOSFET Q1 and is connected to chip U1 through inductor T1.

[0028] The source of MOSFET Q1 is also connected to the source of MOSFET Q2, the drain of MOSFET Q3, the drain of MOSFET Q4, and one end of resistor R15; the gate of MOSFET Q1 is connected to one end of resistor R20, and the other end of resistor R20 is connected to the other end of resistor R15; the diode D2 is connected in parallel with resistor R20; and resistor R20 is also connected to resistor R21.

[0029] The drain of MOSFET Q2 is connected to the drain of MOSFET Q1, the gate of MOSFET Q2 is connected to one end of resistor R16, the other end of resistor R16 is connected to resistor R20, and diode D8 is connected in parallel with resistor R16.

[0030] The drain of MOSFET Q3 is also connected to one end of capacitor C20 and the drain of MOSFET Q4. The source of MOSFET Q3 and the other end of capacitor C20 are both connected to the source of MOSFET Q4. The gate of MOSFET Q3 is connected to the source of MOSFET Q3 through resistors R17 and R18 in series. Diode D6 is connected in parallel with resistor R17. The gate of MOSFET Q4 is connected to one end of resistor R19, and the other end of resistor R19 is connected to resistor R17. Diode D7 is connected in parallel with resistor R19. Resistor R17 is also connected to resistor R23.

[0031] Resistors R21 and R23, the source of MOSFET Q1, and the source of MOSFET Q2 are connected to the PFC oscillation circuit. The drains of MOSFET Q3 and MOSFET Q4 are connected to the mains low-frequency synchronous rectification circuit.

[0032] Preferably, the high-frequency synchronous rectification and filtering circuit includes capacitors C2, C4, C6, C7, C8, C9, C24, C27, C46, ​​magnetic core inductor L4, and terminal CN3.

[0033] The two ends of capacitor C4 are connected to the two ends of magnetic core inductor L4 respectively. Capacitors C6, C7, C8, C9, C24 and C27 are all connected in parallel with capacitor C4. The two ends of capacitor C46 are connected to the two ends of magnetic core inductor L4 and terminal CN3 respectively. One end of capacitor C4 is connected to the source of MOSFET Q1, and the other end of capacitor C4 is connected in series with capacitor C2 between it and magnetic core inductor L4. Capacitor C6 is also connected to capacitor C16. Capacitors C9 and C24 are both connected to the mains low-frequency synchronous rectification circuit.

[0034] Preferably, the mains low-frequency synchronous rectification circuit includes capacitor C51, MOSFET Q5, diode D16, resistors R83, R80, and R79, MOSFET Q6, capacitor C52, resistors R81 and R69, diode D15, resistor R70, diode D14, resistor R62, resistor R49, capacitors C40, C39, C36, C41, C45, C44, and C42, resistors R66, R67, and R56, chip U7, and chip U8.

[0035] The drain of MOSFET Q5 is connected to the source of MOSFET Q1. The drain of MOSFET Q5 is also connected to one end of capacitor C5. The other end of capacitor C5 is connected to one end of common-mode inductor LF2 and the source of MOSFET Q5. The gate of MOSFET Q5 is connected to chip U8 through resistors R83 and R80 connected in series. Diode D16 is connected in parallel with resistor R83. The gate of MOSFET Q5 is also connected to the source of MOSFET Q5 through resistor R79. The source of MOSFET Q5 is also connected to the drain of MOSFET Q6, one end of capacitor C41, one end of capacitor C45, one end of capacitor C44, one end of capacitor C42, and chip U8.

[0036] The other ends of capacitors C41, C45, C44, and C42 are connected to the cathode of diode D14. The cathode of diode D14 is also connected to chip U8. The anode of diode D14 is connected to one end of resistor R62. The other end of resistor R62 is connected to one end of capacitor C40, one end of resistor R49, and chip U8.

[0037] The other end of resistor R49 is connected to resistor R14, and the other end of capacitor C40 is connected to chip U8 and PFC oscillation circuit. Capacitor C39 is connected in parallel with capacitor C40.

[0038] The drain of MOSFET Q6 is connected to the source of MOSFET Q6 through capacitor C52. The gate of MOSFET Q6 is connected to the anode of diode D15 and to the source of MOSFET Q6 through resistor R69. The cathode of diode D15 is connected to one end of resistor R70, and the other end of resistor R70 is connected to chip U8. Resistor R81 is connected in parallel with diode D15. Chip U8 is also connected to one end of resistor R66 and one end of resistor R67. The other ends of resistor R66 and resistor R67 are connected to chip U7.

[0039] The source of the MOSFET Q6 is also connected to the anode of diode D11, capacitors C28, C29, and C30, chip U1, the source of MOSFET Q4, the anode of diode D1, capacitors C9 and C5, the anode of diode D9, capacitor C3, resistor R22, capacitor C23, chip U2, resistor R32, and capacitor C26.

[0040] One pin of chip U7 is connected to pin PG2 of chip U7 via resistor R56, and capacitor C36 is connected in parallel with resistor R56; another pin of chip U7 is connected to one end of capacitor C28, one end of capacitor C47, and one end of capacitor R68, the other end of resistor R68 is connected to resistor R14, and the other ends of capacitor C48 and capacitor C47 are connected to chip U7; chip U7 is also connected to the mains zero-crossing detection circuit.

[0041] The CS pin of chip U7 is connected to resistors R46, R55, R57, and capacitor C37.

[0042] The PG2 pin of chip U7 is connected to capacitors C31, C33, C37, C38, resistors R35, R57, R58, R61, the inverting input terminal of operational amplifier U4, the negative power supply terminal of operational amplifier U4, the negative power supply terminal of operational amplifier U6, capacitor C34, resistor R48, capacitor C24, and chip U5.

[0043] The ZCD pin of chip U7 is connected to resistor R58, capacitor C38, and the drain of MOSFET Q7; the PDL pin of chip U7 is connected to resistor R53.

[0044] Preferably, the PFC oscillation circuit includes resistor R24, diode D10, capacitor C22, resistor R25, capacitor C21, resistor R30, resistor R29, resistor R28, capacitor C25, resistor R52, and chip U3.

[0045] One end of resistor R24 ​​is connected to the positive terminal of diode D10, the negative terminal of diode D10 is connected to one end of capacitor C22 and chip U3, and the other end of capacitor C22 is connected to the ACLO pin of chip U3.

[0046] The other end of resistor R24 ​​is connected to one end of resistor R25, chip U3 and one end of capacitor C21. The other end of resistor R25 is connected to resistor R14. The other end of capacitor C21 is connected to the source of MOSFET Q6.

[0047] One end of resistor R30 is connected to chip U3, and the other end of resistor R30 is connected to the PWH pin of chip U5 and chip U7; one end of resistor R29 is connected to chip U3, and the other end of resistor R29 is connected to the PWL pin of chip U5 and one end of resistor R52 is connected to chip U7.

[0048] One pin of chip U3 is connected to the 5V power supply terminal of chip U5, and is also connected to another pin of chip U3 and one end of capacitor C25. The other end of capacitor C25 is connected to chip U3 and one end of resistor R28. The other end of resistor R28 is connected to chip U3.

[0049] The chip U3, resistor R28, and capacitor C25 are all connected to the source of MOSFET Q6; the PWH1 pin of chip U3 is connected to resistor R21; the PWL1 pin of chip U3 is connected to resistor R23; and the ACLO pin of chip U3 is connected to the source of MOSFET Q1 and the source of MOSFET Q2.

[0050] Preferably, the mains zero-crossing detection circuit includes resistors R33, R65, R63, capacitors C43, R64, R71, R72, R73, capacitor C50, R78, R74, R75, R76, capacitor C49, and resistor R77.

[0051] One end of resistor R33 is connected to the drain of MOSFET Q1, and the other end of resistor R33 is connected to pin PG2 of chip U7 through resistors R65, R63 and R64 connected in series. Capacitor C43 is connected in parallel with resistor R64 and is also connected to pin FB of chip U7.

[0052] One end of resistor R71 is connected to one end of common-mode inductor LF2. The other end of resistor R71 is connected to pin PG2 of chip U7 through resistors R72, R73 and R78 connected in series. Capacitor C50 is connected in parallel with resistor R78 and is also connected to pin LVS1 of chip U7.

[0053] One end of resistor R74 is connected to the other end of common-mode inductor LF2. The other end of resistor R74 is connected to pin PG2 of chip U7 through resistors R75, R76 and R77 connected in series. Capacitor C49 is connected to resistor R77. Capacitor C49 is also connected to pin LVS2 of chip U7.

[0054] Compared with the prior art, the advantages of the totem-based bridgeless PFC switching power supply circuit described in this utility model are mainly reflected in:

[0055] The DC power is filtered by a filtering circuit to select the signal frequency. The processed voltage signal is then input to a PFC current detection circuit for current detection. Simultaneously, a conversion circuit within the PFC current detection circuit converts the DC power to AC power. This AC power is then boosted by a PFC boost circuit to output 400V, and finally processed by a high-frequency synchronous rectification and filtering circuit to provide a stable power supply to the load. A PFC oscillation circuit controls the shape and frequency of the input and output currents of the PFC boost circuit, reducing harmonic noise and maintaining the stability and reliability of the power supply circuit. Zero-crossing detection is achieved through a mains zero-crossing detection circuit connected to a low-frequency synchronous rectification circuit. The zero-crossing detection circuit transmits zero-crossing information to the low-frequency synchronous rectification circuit, which precisely controls the switching on or off when the voltage crosses zero. This reduces switching losses and electromagnetic interference during rectification, improving rectification efficiency.

[0056] The PFC current detection circuit collects current through chip U1 and then transmits the current data to operational amplifier U6. Current detection is achieved through the cooperation of chip U1 and operational amplifier U6.

[0057] In the PFC boost circuit, MOSFETs Q1, Q2, Q3, and Q4 connect the PFC boost circuit and the high-frequency synchronous rectification and filtering circuit. MOSFETs Q1 and Q2 are high-side switches used to control the magnitude and waveform of the input current. They also work with inductor T1 and capacitor C19 to boost the input voltage to the required voltage. When MOSFETs Q1 and Q2 are turned on, the output voltage is output to the output terminal through MOSFETs Q1 and Q2 and inductor T2, while inductor T2 stores energy. When MOSFETs Q1 and Q2 are turned off, the energy stored in inductor T2 is released to the output terminal through a diode, maintaining the stability of the output voltage.

[0058] MOSFETs Q3 and Q4 are low-side switches. When the input voltage fluctuates or the load changes, MOSFETs Q3 and Q4 are used to assist in regulating the current and maintaining a stable output voltage. The efficiency and reliability of the circuit are improved by the coordinated operation of MOSFETs Q1, Q2, Q3 and Q4.

[0059] This invention improves the efficiency and reliability of a PFC boost circuit by setting up a high-side switch and a low-side switch, and makes the output voltage of the circuit stable by having the high-side switch and the low-side switch work together. Attached Figure Description

[0060] The above and other objects, features, and advantages of this invention will become clearer through a more detailed description of the preferred embodiments shown in the accompanying drawings. The same reference numerals indicate the same parts throughout the drawings, and the drawings are not intentionally drawn to scale with actual dimensions; the focus is on illustrating the gist of this invention.

[0061] Figure 1 This is a schematic diagram of the present invention.

[0062] Figure 2 This is a schematic diagram of the filter circuit, surge circuit, mains zero-crossing detection circuit, and high-frequency synchronous rectification and filter circuit in this utility model.

[0063] Figure 3 This is a schematic diagram of the PFC current detection circuit and the PFC boost circuit in the utility model.

[0064] Figure 4 This is a schematic diagram of a low-frequency synchronous rectifier circuit for mains power and a PFC oscillation control circuit for utility models.

[0065] Figure descriptions: Filter circuit 1, surge circuit 2, mains zero-crossing detection circuit 3, mains low-frequency synchronous rectification circuit 4, PFC current detection circuit 5, PFC boost circuit 6, PFC oscillation control circuit 7, high-frequency synchronous rectification and filtering circuit 8, first chip circuit 51, arithmetic circuit 52, second chip circuit 53, conversion circuit 54. Detailed Implementation

[0066] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand this utility model and implement it. However, the embodiments are not intended to limit this utility model. In this embodiment, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this utility model.

[0067] It should be noted that when one element is considered to be "connected" to another element, it can be directly connected to and integrated with the other element, or there may be an intervening element present. The terms "mounted," "one end," "the other end," and similar expressions used in this invention are for illustrative purposes only.

[0068] A totem-style bridgeless PFC switching power supply circuit, such as Figure 1-4 As shown, the circuit includes a filter circuit 1, a surge circuit 2, a mains power zero-crossing detection circuit 3, a mains power low-frequency synchronous rectification circuit 4, a PFC current detection circuit 5, a PFC boost circuit 6, a PFC oscillation control circuit 7, and a high-frequency synchronous rectification and filter circuit 8. The filter circuit 1, PFC current detection circuit 5, PFC boost circuit 6, and high-frequency synchronous rectification and filter circuit 8 are connected in sequence. The filter circuit 1 is also connected to the power input terminal, the surge circuit 2, and the mains power zero-crossing detection circuit 3. The PFC boost circuit 6 is also connected to the PFC oscillation control circuit 7. The mains power zero-crossing detection circuit 3 is connected to the PFC oscillation control circuit 7 through the mains power low-frequency synchronous rectification circuit 4, and the high-frequency synchronous rectification and filter circuit 8 is connected to the output terminal.

[0069] like Figure 2As shown, surge circuit 2 includes impedance Z1, resistor R8, relay JDQ1, resistor R13, resistor R14 and diode D1; filter circuit 1 includes terminal CN2, magnetic core inductor L1, common mode inductor LF1, common mode inductor LF2, common mode inductor LF3, resistor R40, resistor R41, resistor R59, resistor R60, capacitor C10, capacitor C11, capacitor C12, capacitor C13, capacitor C14 and capacitor C15.

[0070] The two ends of common mode inductor LE3, the two ends of common mode inductor LE2, and the two ends of common mode inductor LE2 are connected in sequence and connected to the power input terminal through terminal CN2. Terminal CN2 is grounded through magnetic core inductor L1.

[0071] Impedance Z1 is connected in parallel across the common-mode inductor LE3, and capacitors C10 and C11 are connected in parallel across the common-mode inductor LF1. One end of impedance Z1 is connected to one end of common-mode inductor LF1, and the other end of impedance Z1 is connected to the other end of common-mode inductor LF1 through resistor R8.

[0072] One end of the common-mode inductor LF1 is connected in series with resistors R60, R40, and the other end of the common-mode inductor LF1; resistors R59 and R60 are connected in parallel, and resistors R41 and R40 are connected in parallel.

[0073] One end of the impedance Z1 is also connected to one end of the capacitor C13. The other end of the capacitor C13 is connected to one end of the capacitor C12, one end of the capacitor C15, and one end of the capacitor C14. The other end of the capacitor C12 is connected to the other end of the impedance Z1. The other end of the capacitor C15 is connected to one end of the common-mode inductor LF2. The other end of the capacitor C14 is connected to the other end of the common-mode inductor LF2. The common-mode inductor LF2 is connected to the mains zero-crossing detection circuit 3, the PFC current detection circuit 5, and the mains low-frequency synchronous rectification circuit 4.

[0074] The resistor R8 is also connected in parallel with the relay JDQ1. One end of the relay JDQ1 is connected to one end of the resistor R14 and the negative terminal of the diode D1. The positive terminal of the diode D1 is connected to the other end of the relay JDQ1. The other end of the resistor R14 and the positive terminal of the diode D1 are also connected to the PFC oscillation control circuit 7 and the PFC current control circuit. The resistor R14 is connected in parallel with the resistor R13.

[0075] like Figure 3 As shown, the PFC current detection circuit 5 includes a first chip circuit 51, an arithmetic circuit 52, a second chip circuit 53, and a conversion circuit 54.

[0076] The first chip circuit 51 includes chip U1, resistor R27, capacitor C28, capacitor C29, and capacitor C30. In this embodiment, chip U1 is a CT430.

[0077] The operational circuit 52 includes operational amplifier U6, MOSFET Q7, operational amplifier U4, capacitors C28, C29, C30, C32, C33, C35, C37, and C38, and resistors R34, R35, R36, R37, R38, R42, R43, R44, R45, R46, R47, R51, R54, R55, R57, R58, and R61. In this embodiment, operational amplifier U6 is model NCS20072.

[0078] The second chip circuit 53 includes resistors R48, R50, and R53, capacitors C31 and C34, and chip U5. In this embodiment, chip U5 is model AC157G.

[0079] The conversion circuit 54 includes Zener diodes D3, D4, D5, D9, C12, and D13; capacitors C1, C3, C5, C17, C18, C23, and C26; resistors R22, R26, R31, and R32; power supply chip IC1; chip U2; magnetic core inductor L2; and terminal block CN1. In this embodiment, power supply chip IC1 is model AP8012H, and chip U2 is model NCP730.

[0080] In the first chip circuit 51, one pin of chip U1 is connected to one end of common mode inductor LF2; chip U1 is also connected to the low-frequency synchronous rectified current of the mains power through capacitors C28, C29 and C30 respectively.

[0081] In the operational circuit 52, one end of the resistor R37 is connected to the chip U1, and the other end of the resistor R37 is connected in series with the resistors R54, R55 and R57 in sequence; the other end of the resistor R37 is also connected to an inverting input terminal of the operational amplifier U6, and the resistor R54 is connected to an output terminal of the operational amplifier U6.

[0082] One end of resistor R51 is connected to chip U1, and the other end of resistor R51 is connected to resistor R37 through capacitor C35. The other end of resistor R51 is also connected to one end of resistor R61 and a common in-phase input terminal of operational amplifier U6. One output terminal of operational amplifier U6 is also connected to the drain of MOS transistor Q7 through resistor R44.

[0083] One end of resistor R34 is connected to chip U1, and the other end of resistor R34 is connected in series with resistors R42, R38, and R46 in sequence. Resistor R46 is also connected to a capacitor. The other end of resistor R34 is also connected to another non-inverting input terminal of operational amplifier. One end of resistor R36 is connected to chip U1, and the other end of resistor R36 is connected to resistor R34 through capacitor C32. The other end of resistor R36 is also connected to one end of resistor R35 and another inverting input terminal of operational amplifier U6. One end of resistor R38 is also connected to another output terminal of operational amplifier U6, and the other end of resistor R38 is also connected to the drain of MOSFET Q7 through resistor R45. The positive power supply terminal of operational amplifier U6 is connected to one end of resistor R43.

[0084] The other end of the resistor R43 is connected to the capacitor C33 and the positive power supply terminal of the operational amplifier U4. The output terminal of the operational amplifier U4 is connected to the gate of the MOSFET Q7. The drain of the MOSFET Q7 is also connected to the resistor R58 and the capacitor C38.

[0085] The capacitor C33, resistors R35, R46, R57, R61, capacitor C37, negative power supply terminal of operational amplifier U6, resistor R58, capacitor C38, drain of MOSFET Q7, non-inverting input terminal of operational amplifier U4, inverting input terminal of operational amplifier U4, and negative power supply terminal of operational amplifier U4 are all connected to the mains low-frequency synchronous rectifier circuit 4.

[0086] In the second chip circuit 53, the 5V power supply terminal of chip U5 is connected to chip U1 through resistor R27. The 5V power supply terminal of chip U5 is also connected to one end of capacitor C31. The other pin of chip U5 is connected to one end of resistor R53 and one end of resistor R48. Chip U5 is also connected to the mains low-frequency synchronous rectification circuit 4. One end of resistor R50 is connected to resistor R14. The other end of resistor R50 is connected to the positive input terminal of operational amplifier U6 and one end of capacitor C34. The other ends of capacitor C34, resistor R53, and resistor R48 are all connected to the mains low-frequency synchronous rectification circuit 4. The ZA pin of chip U5 is connected to the non-inverting input terminal of operational amplifier U4.

[0087] In the conversion circuit 54, one pin of the power chip IC1 is connected to the negative terminals of diodes D13 and D12 and capacitor C5; the positive terminal of diode D12 is connected to one end of common-mode inductor LF2; and the positive terminal of diode D13 is connected to the other end of common-mode inductor LF2. Another pin of the power chip IC1 is connected to the negative terminal of diode D14; the positive terminal of diode D14 is connected to the negative terminal of diode D5; the positive terminal of diode D5 is connected to one end of magnetic core inductor L2 and capacitor C13; and the other end of magnetic core inductor L2 is connected to one end of capacitor C17, the negative terminal of diode D9, one end of capacitor C18, one end of capacitor C1, and the power chip IC1.

[0088] The other end of capacitor C17 and the negative terminal of diode D5 are connected to the negative terminal of Zener diode D3. The positive terminal of Zener diode D3 is connected to the other end of capacitor C18 and power chip IC1. The other end of capacitor C1 is connected to the negative terminal of diode D4.

[0089] The positive terminal of diode D5 is also connected to resistor R22, and is connected to one end of resistors R14 and R26 through terminal CN1. The other end of resistor R26 is connected to capacitor C23 and one pin of chip U2. The other pin of chip U2 is connected to another pin of chip U2 through series resistors R31 and R32. Resistor R31 is also connected to capacitor C26 and the 5V power supply terminal of chip U5. The positive terminal of diode D9, capacitors C5, C13, C23, R22, R32, and C26 are all connected to the mains low-frequency synchronous rectifier circuit 4.

[0090] like Figure 3 As shown, the PFC boost circuit 6 includes a high-side switch, a low-side switch, resistors R15, R16, R17, R18, R19, R20, R21, and R23, capacitors C19 and C20, inductor T1, diodes D2, D6, D7, D8, D10, and D11. The high-side switches are MOSFETs Q1 and Q2; the low-side switches are MOSFETs Q3 and Q4.

[0091] The source of MOSFET Q1 is also connected to the source of MOSFET Q2, the drain of MOSFET Q3, the drain of MOSFET Q4, and one end of resistor R15; the gate of MOSFET Q1 is connected to one end of resistor R20, and the other end of resistor R20 is connected to the other end of resistor R15; the diode D2 is connected in parallel with resistor R20; and resistor R20 is also connected to resistor R21.

[0092] The drain of MOSFET Q2 is connected to the drain of MOSFET Q1, the gate of MOSFET Q2 is connected to one end of resistor R16, the other end of resistor R16 is connected to resistor R20, and diode D8 is connected in parallel with resistor R16.

[0093] The drain of MOSFET Q3 is also connected to one end of capacitor C20 and the drain of MOSFET Q4. The source of MOSFET Q3 and the other end of capacitor C20 are both connected to the source of MOSFET Q4. The gate of MOSFET Q3 is connected to the source of MOSFET Q3 through resistors R17 and R18 in series. Diode D6 is connected in parallel with resistor R17. The gate of MOSFET Q4 is connected to one end of resistor R19, and the other end of resistor R19 is connected to resistor R17. Diode D7 is connected in parallel with resistor R19. Resistor R17 is also connected to resistor R23.

[0094] Resistors R21 and R23, the source of MOSFET Q1, and the source of MOSFET Q2 are connected to the PFC oscillation circuit. The drains of MOSFET Q3 and MOSFET Q4 are connected to the mains low-frequency synchronous rectifier circuit 4.

[0095] like Figure 2 As shown, the high-frequency synchronous rectification and filtering circuit includes capacitors C2, C4, C6, C7, C8, C9, C24, C27, C46, ​​magnetic core inductor L4, and terminal CN3.

[0096] The two ends of capacitor C4 are connected to the two ends of magnetic core inductor L4 respectively. Capacitors C6, C7, C8, C9, C24 and C27 are all connected in parallel with capacitor C4. The two ends of capacitor C46 are connected to the two ends of magnetic core inductor L4 and terminal CN3 respectively. One end of capacitor C4 is connected to the source of MOSFET Q1, and the other end of capacitor C4 is connected in series with capacitor C2 between it and magnetic core inductor L4. Capacitor C6 is also connected to capacitor C16. Capacitors C9 and C24 are both connected to the mains low-frequency synchronous rectification circuit 4.

[0097] like Figure 4 As shown, the mains low-frequency synchronous rectification circuit 4 includes capacitor C51, MOSFET Q5, diode D16, resistors R83, R80, and R79, MOSFET Q6, capacitor C52, resistors R81 and R69, diode D15, resistor R70, diode D14, resistor R62, resistor R49, capacitors C40, C39, C36, C41, C45, C44, and C42, resistors R66, R67, and R56, chip U7, and chip U8. In this embodiment, chip U7 is model NCP1681; chip U8 is model NCP535108.

[0098] The drain of MOSFET Q5 is connected to the source of MOSFET Q1. The drain of MOSFET Q5 is also connected to one end of capacitor C5. The other end of capacitor C5 is connected to one end of common-mode inductor LF2 and the source of MOSFET Q5. The gate of MOSFET Q5 is connected to chip U8 through resistors R83 and R80 connected in series. Diode D16 is connected in parallel with resistor R83. The gate of MOSFET Q5 is also connected to the source of MOSFET Q5 through resistor R79. The source of MOSFET Q5 is also connected to the drain of MOSFET Q6, one end of capacitor C41, one end of capacitor C45, one end of capacitor C44, one end of capacitor C42, and chip U8.

[0099] The other ends of capacitors C41, C45, C44, and C42 are connected to the cathode of diode D14. The cathode of diode D14 is also connected to chip U8. The anode of diode D14 is connected to one end of resistor R62. The other end of resistor R62 is connected to one end of capacitor C40, one end of resistor R49, and chip U8.

[0100] The other end of resistor R49 is connected to resistor R14, and the other end of capacitor C40 is connected to chip U8 and PFC oscillation circuit. Capacitor C39 is connected in parallel with capacitor C40.

[0101] The drain of MOSFET Q6 is connected to the source of MOSFET Q6 through capacitor C52. The gate of MOSFET Q6 is connected to the anode of diode D15 and to the source of MOSFET Q6 through resistor R69. The cathode of diode D15 is connected to one end of resistor R70, and the other end of resistor R70 is connected to chip U8. Resistor R81 is connected in parallel with diode D15. Chip U8 is also connected to one end of resistor R66 and one end of resistor R67. The other ends of resistor R66 and resistor R67 are connected to chip U7.

[0102] The source of the MOSFET Q6 is also connected to the anode of diode D11, capacitors C28, C29, and C30, chip U1, the source of MOSFET Q4, the anode of diode D1, capacitors C9 and C5, the anode of diode D9, capacitor C3, resistor R22, capacitor C23, chip U2, resistor R32, and capacitor C26.

[0103] One pin of chip U7 is connected to pin PG2 of chip U7 via resistor R56, and capacitor C36 is connected in parallel with resistor R56; the other pin of chip U7 is connected to one end of capacitor C28, one end of capacitor C47 and one end of capacitor R68, the other end of resistor R68 is connected to resistor R14, and the other ends of capacitor C48 and capacitor C47 are connected to chip U7; chip U7 is also connected to mains zero-crossing detection circuit 3.

[0104] Reference Figure 2-4 As shown, the CS pin of chip U7 is connected to resistors R46, R55, R57, and capacitor C37.

[0105] The PG2 pin of chip U7 is connected to capacitors C31, C33, C37, C38, resistors R35, R57, R58, R61, the inverting input terminal of operational amplifier U4, the negative power supply terminal of operational amplifier U4, the negative power supply terminal of operational amplifier U6, capacitor C34, resistor R48, capacitor C24, and chip U5.

[0106] The ZCD pin of chip U7 is connected to resistor R58, capacitor C38, and the drain of MOSFET Q7; the PDL pin of chip U7 is connected to resistor R53.

[0107] The PFC oscillation circuit includes resistor R24, diode D10, capacitor C22, resistor R25, capacitor C21, resistor R30, resistor R29, resistor R28, capacitor C25, resistor R52, and chip U3. In this embodiment, chip U3 is model NCV51561.

[0108] One end of resistor R24 ​​is connected to the positive terminal of diode D10, the negative terminal of diode D10 is connected to one end of capacitor C22 and chip U3, and the other end of capacitor C22 is connected to the ACLO pin of chip U3.

[0109] The other end of resistor R24 ​​is connected to one end of resistor R25, chip U3 and one end of capacitor C21. The other end of resistor R25 is connected to resistor R14. The other end of capacitor C21 is connected to the source of MOSFET Q6.

[0110] One end of resistor R30 is connected to chip U3, and the other end of resistor R30 is connected to the PWH pin of chip U5 and chip U7; one end of resistor R29 is connected to chip U3, and the other end of resistor R29 is connected to the PWL pin of chip U5 and one end of resistor R52 is connected to chip U7.

[0111] One pin of chip U3 is connected to the 5V power supply terminal of chip U5, and is also connected to another pin of chip U3 and one end of capacitor C25. The other end of capacitor C25 is connected to chip U3 and one end of resistor R28. The other end of resistor R28 is connected to chip U3.

[0112] The chip U3, resistor R28, and capacitor C25 are all connected to the source of MOSFET Q6; the PWH1 pin of chip U3 is connected to resistor R21; the PWL1 pin of chip U3 is connected to resistor R23; and the ACLO pin of chip U3 is connected to the source of MOSFET Q1 and the source of MOSFET Q2.

[0113] like Figure 2 As shown, the mains zero-crossing detection circuit 3 includes resistors R33, R65, R63, capacitors C43, R64, R71, R72, R73, capacitors C50, R78, R74, R75, R76, capacitor C49, and resistor R77.

[0114] One end of resistor R33 is connected to the drain of MOSFET Q1, and the other end of resistor R33 is connected to pin PG2 of chip U7 through resistors R65, R63 and R64 connected in series. Capacitor C43 is connected in parallel with resistor R64 and is also connected to pin FB of chip U7.

[0115] One end of resistor R71 is connected to one end of common-mode inductor LF2. The other end of resistor R71 is connected to pin PG2 of chip U7 through resistors R72, R73 and R78 connected in series. Capacitor C50 is connected in parallel with resistor R78 and is also connected to pin LVS1 of chip U7.

[0116] One end of resistor R74 is connected to the other end of common-mode inductor LF2. The other end of resistor R74 is connected to pin PG2 of chip U7 through resistors R75, R76 and R77 connected in series. Capacitor C49 is connected to resistor R77. Capacitor C49 is also connected to pin LVS2 of chip U7.

[0117] This invention uses a filter circuit 1 to filter the DC power, achieving frequency selection of the signal. The processed voltage signal is then input to a PFC current detection circuit 5 for current detection. Simultaneously, a conversion circuit 54 within the PFC current detection circuit 5 converts the DC power to AC power. The PFC boost circuit 6 then boosts the voltage to output 400V, which is then processed by a high-frequency synchronous rectification and filtering circuit 8 to provide a stable power supply to the load. A PFC oscillation circuit controls the shape and frequency of the input and output current of the PFC boost circuit 6, reducing harmonic noise and maintaining the stability and reliability of the power supply circuit. Zero-crossing detection is achieved through a mains zero-crossing detection circuit 3, connected to a low-frequency synchronous rectification circuit 4. The zero-crossing detection circuit 3 transmits zero-crossing information to the low-frequency synchronous rectification circuit 4, which precisely controls the switching on or off when the voltage crosses zero. This reduces switching losses and electromagnetic interference during rectification, improving rectification efficiency.

[0118] In the PFC current detection circuit 5, chip U1 acts as a current transformer. The current is collected through chip U1, and then the current data is transmitted to operational amplifier U6. Current detection is achieved through the cooperation of chip U1 and operational amplifier U6.

[0119] In the PFC boost circuit 6, MOSFETs Q1, Q2, Q3, and Q4 connect the PFC boost circuit 6 and the high-frequency synchronous rectification and filtering circuit. MOSFETs Q1 and Q2 are high-side switches used to control the magnitude and waveform of the input current. They also work with inductor T1 and capacitor C19 to boost the input voltage to the required voltage. When MOSFETs Q1 and Q2 are turned on, the output voltage is output to the output terminal through MOSFETs Q1 and Q2 and inductor T2, while inductor T2 stores energy. When MOSFETs Q1 and Q2 are turned off, the energy stored in inductor T2 is released to the output terminal through the diode, maintaining the stability of the output voltage.

[0120] MOSFETs Q3 and Q4 are low-side switches. When the input voltage fluctuates or the load changes, MOSFETs Q3 and Q4 are used to assist in regulating the current and maintaining a stable output voltage. The efficiency and reliability of the circuit are improved by the coordinated operation of MOSFETs Q1, Q2, Q3 and Q4.

[0121] This invention improves the efficiency and reliability of the circuit and stabilizes the output voltage by setting up a PFC boost circuit 6 with high-side and low-side switching transistors.

[0122] In this specification, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0123] In the description of this specification, the references to terms such as "preferred embodiment," "another embodiment," "other embodiment," or "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0124] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A totem-style bridgeless PFC switching power supply circuit, characterized in that: It includes a filter circuit, a surge circuit, a mains zero-crossing detection circuit, a mains low-frequency synchronous rectification circuit, a PFC current detection circuit, a PFC boost circuit, a PFC oscillation control circuit, and a high-frequency synchronous rectification and filter circuit; the filter circuit, PFC current detection circuit, PFC boost circuit, and high-frequency synchronous rectification and filter circuit are connected in sequence; the filter circuit is also connected to the power input terminal, the surge circuit, and the mains zero-crossing detection circuit; the PFC boost circuit is also connected to the PFC oscillation control circuit; the mains zero-crossing detection circuit is connected to the PFC oscillation control circuit through the mains low-frequency synchronous rectification circuit, the high-frequency synchronous rectification and filter circuit is connected to the output terminal, and the PFC boost circuit has a high-side switch and a low-side switch.

2. The switching power supply circuit of the totem bridgeless PFC according to claim 1, characterized in that: The surge circuit includes impedance Z1, resistor R8, relay JDQ1, resistor R13, resistor R14, and diode D1; the filter circuit includes terminal block CN2, magnetic core inductor L1, common mode inductor LF1, common mode inductor LF2, common mode inductor LF3, resistor R40, resistor R41, resistor R59, resistor R60, capacitor C10, capacitor C11, capacitor C12, capacitor C13, capacitor C14, and capacitor C15; The two ends of common mode inductor LE3, the two ends of common mode inductor LE2, and the two ends of common mode inductor LE2 are connected in sequence and connected to the power input terminal through terminal CN2. Terminal CN2 is grounded through magnetic core inductor L1. Impedance Z1 is connected in parallel across the common-mode inductor LE3, and capacitors C10 and C11 are connected in parallel across the common-mode inductor LF1. One end of impedance Z1 is connected to one end of common-mode inductor LF1, and the other end of impedance Z1 is connected to the other end of common-mode inductor LF1 through resistor R8. One end of the common-mode inductor LF1 is connected in series with resistors R60, R40, and the other end of the common-mode inductor LF1; resistors R59 and R60 are connected in parallel, and resistors R41 and R40 are connected in parallel. One end of the impedance Z1 is also connected to one end of the capacitor C13. The other end of the capacitor C13 is connected to one end of the capacitor C12, one end of the capacitor C15, and one end of the capacitor C14. The other end of the capacitor C12 is connected to the other end of the impedance Z1. The other end of the capacitor C15 is connected to one end of the common-mode inductor LF2. The other end of the capacitor C14 is connected to the other end of the common-mode inductor LF2. The common-mode inductor LF2 is connected to the mains zero-crossing detection circuit, the PFC current detection circuit, and the mains low-frequency synchronous rectification circuit. The resistor R8 is also connected in parallel with the relay JDQ1. One end of the relay JDQ1 is connected to one end of the resistor R14 and the negative terminal of the diode D1. The positive terminal of the diode D1 is connected to the other end of the relay JDQ1. The other end of the resistor R14 and the positive terminal of the diode D1 are also connected to the PFC oscillation control circuit and the PFC current control circuit. The resistor R14 is connected in parallel with the resistor R13.

3. The switching power supply circuit of the totem bridgeless PFC according to claim 2, characterized in that: The PFC current detection circuit includes a first chip circuit, an arithmetic circuit, a second chip circuit, and a conversion circuit; the first chip circuit includes chip U1, resistor R27, capacitor C28, capacitor C29, and capacitor C30. One pin of chip U1 is connected to one end of common-mode inductor LF2; chip U1 is also connected to the low-frequency synchronous rectified current of the mains power through capacitors C28, C29 and C30 respectively. The operational circuit includes operational amplifier U6, MOSFET Q7, operational amplifier U4, capacitors C28, C29, C30, C32, C33, C35, C37, and C38, and resistors R34, R35, R36, R37, R38, R42, R43, R44, R45, R46, R47, R51, R54, R55, R57, R58, and R61. One end of resistor R37 is connected to chip U1, and the other end of resistor R37 is connected in series with resistors R54, R55 and R57 in sequence; the other end of resistor R37 is also connected to an inverting input terminal of operational amplifier U6, and resistor R54 is connected to an output terminal of operational amplifier U6. One end of resistor R51 is connected to chip U1, and the other end of resistor R51 is connected to resistor R37 through capacitor C35. The other end of resistor R51 is also connected to one end of resistor R61 and a common in-phase input terminal of operational amplifier U6. One output terminal of operational amplifier U6 is also connected to the drain of MOS transistor Q7 through resistor R44. One end of resistor R34 is connected to chip U1, and the other end of resistor R34 is connected in series with resistors R42, R38, and R46 in sequence. Resistor R46 is also connected to a capacitor. The other end of resistor R34 is also connected to another non-inverting input terminal of operational amplifier U6. One end of resistor R36 is connected to chip U1, and the other end of resistor R36 is connected to resistor R34 through capacitor C32. The other end of resistor R36 is also connected to one end of resistor R35 and another inverting input terminal of operational amplifier U6. One end of resistor R38 is also connected to another output terminal of operational amplifier U6, and the other end of resistor R38 is also connected to the drain of MOSFET Q7 through resistor R45. The positive power supply terminal of operational amplifier U6 is connected to one end of resistor R43. The other end of the resistor R43 is connected to the capacitor C33 and the positive power supply terminal of the operational amplifier U4. The output terminal of the operational amplifier U4 is connected to the gate of the MOSFET Q7. The drain of the MOSFET Q7 is also connected to the resistor R58 and the capacitor C38. The capacitor C33, resistors R35, R46, R57, R61, capacitor C37, negative power supply terminal of operational amplifier U6, resistor R58, capacitor C38, drain of MOSFET Q7, non-inverting input terminal of operational amplifier U4, inverting input terminal of operational amplifier U4, and negative power supply terminal of operational amplifier U4 are all connected to the mains low-frequency synchronous rectification circuit.

4. The switching power supply circuit of the totem bridgeless PFC according to claim 3, characterized in that: The second chip circuit includes resistors R48, R50, and R53, capacitors C31 and C34, and chip U5. The 5V power supply terminal of chip U5 is connected to chip U1 via resistor R27. The 5V power supply terminal of chip U5 is also connected to one end of capacitor C31. The other pin of chip U5 is connected to one end of resistor R53 and one end of resistor R48. Chip U5 is also connected to a low-frequency synchronous rectifier circuit. One end of resistor R50 is connected to resistor R14. The other end of resistor R50 is connected to the positive input terminal of operational amplifier U6 and one end of capacitor C34. The other ends of capacitor C34, resistor R53, and resistor R48 are all connected to the low-frequency synchronous rectifier circuit. The ZA pin of chip U5 is connected to the non-inverting input terminal of operational amplifier U4. The conversion circuit includes Zener diodes D3, D4, D5, D9, C12, and D13; capacitors C1, C3, C5, C17, C18, C23, and C26; resistors R22, R26, R31, and R32; power chip IC1; chip U2; magnetic core inductor L2; and terminal block CN1. One pin of the power chip IC1 is connected to the negative terminals of diodes D13 and D12 and capacitor C5. The positive terminal of diode D12 is connected to one end of common-mode inductor LF2, and the positive terminal of diode D13 is connected to the other end of common-mode inductor LF2. Another pin of the power chip IC1 is connected to the negative terminal of diode D14. The positive terminal of diode D14 is connected to the negative terminal of diode D5. The positive terminal of diode D5 is connected to one end of magnetic core inductor L2 and capacitor C13. The other end of magnetic core inductor L2 is connected to one end of capacitor C17, the negative terminal of diode D9, one end of capacitor C18, one end of capacitor C1, and the power chip IC1. The other end of capacitor C17 and the negative terminal of diode D5 are connected to the negative terminal of Zener diode D3. The positive terminal of Zener diode D3 is connected to the other end of capacitor C18 and power chip IC1. The other end of capacitor C1 is connected to the negative terminal of diode D4. The positive terminal of diode D5 is also connected to resistor R22, and is connected to one end of resistors R14 and R26 through terminal CN1. The other end of resistor R26 is connected to capacitor C23 and one pin of chip U2. The other pin of chip U2 is connected to another pin of chip U2 through series resistors R31 and R32. Resistor R31 is also connected to capacitor C26 and the 5V power supply terminal of chip U5. The positive terminal of diode D9, capacitors C5, C13, C23, R22, R32, and C26 are all connected to the mains low-frequency synchronous rectification circuit.

5. The switching power supply circuit of the totem bridgeless PFC according to claim 4, characterized in that: The high-side switching transistors are MOSFETs Q1 and Q2; the low-side switching transistors are MOSFETs Q3 and Q4; the PFC boost circuit also includes resistors R15, R16, R17, R18, R19, R20, R21, R23, capacitors C19 and C20, inductor T1, diodes D2, D6, D7, D8, D10, and D11; The source of the MOSFET Q1 is connected to the low-frequency synchronous rectification circuit of the mains power through diodes D10 and D11 connected in series. The source of the MOSFET Q1 is also connected to the high-frequency synchronous control circuit. The source of the MOSFET Q1 is also connected to one end of capacitor C19. The other end of capacitor C19 is connected to the source of the MOSFET Q1 and connected to chip U1 through inductor T1. The source of MOSFET Q1 is also connected to the source of MOSFET Q2, the drain of MOSFET Q3, the drain of MOSFET Q4, and one end of resistor R15; the gate of MOSFET Q1 is connected to one end of resistor R20, and the other end of resistor R20 is connected to the other end of resistor R15; diode D2 is connected in parallel with resistor R20; resistor R20 is also connected to resistor R21. The drain of the MOSFET Q2 is connected to the drain of the MOSFET Q1, the gate of the MOSFET Q2 is connected to one end of the resistor R16, the other end of the resistor R16 is connected to the resistor R20, and the diode D8 is connected in parallel with the resistor R16. The drain of MOSFET Q3 is also connected to one end of capacitor C20 and the drain of MOSFET Q4. The source of MOSFET Q3 and the other end of capacitor C20 are both connected to the source of MOSFET Q4. The gate of MOSFET Q3 is connected to the source of MOSFET Q3 through resistors R17 and R18 in series. Diode D6 is connected in parallel with resistor R17. The gate of MOSFET Q4 is connected to one end of resistor R19, and the other end of resistor R19 is connected to resistor R17. Diode D7 is connected in parallel with resistor R19. Resistor R17 is also connected to resistor R23. Resistors R21 and R23, the source of MOSFET Q1, and the source of MOSFET Q2 are connected to the PFC oscillation circuit. The drains of MOSFET Q3 and MOSFET Q4 are connected to the mains low-frequency synchronous rectification circuit.

6. The switching power supply circuit of the totem bridgeless PFC according to claim 5, characterized in that: The high-frequency synchronous rectification and filtering circuit includes capacitors C2, C4, C6, C7, C8, C9, C24, C27, C46, ​​magnetic core inductor L4, and terminal CN3. The two ends of capacitor C4 are connected to the two ends of magnetic core inductor L4 respectively. Capacitors C6, C7, C8, C9, C24 and C27 are all connected in parallel with capacitor C4. The two ends of capacitor C46 are connected to the two ends of magnetic core inductor L4 and terminal CN3 respectively. One end of capacitor C4 is connected to the source of MOSFET Q1, and the other end of capacitor C4 is connected in series with capacitor C2 between it and magnetic core inductor L4. Capacitor C6 is also connected to capacitor C16. Capacitors C9 and C24 are both connected to the mains low-frequency synchronous rectification circuit.

7. The switching power supply circuit of the totem bridgeless PFC according to claim 6, characterized in that: The mains low-frequency synchronous rectification circuit includes capacitor C51, MOSFET Q5, diode D16, resistors R83, R80, and R79, MOSFET Q6, capacitor C52, resistors R81 and R69, diode D15, resistor R70, diode D14, resistor R62, resistor R49, capacitors C40, C39, C36, C41, C45, C44, and C42, resistors R66, R67, and R56, chip U7, and chip U8; The drain of MOSFET Q5 is connected to the source of MOSFET Q1. The drain of MOSFET Q5 is also connected to one end of capacitor C5. The other end of capacitor C5 is connected to one end of common-mode inductor LF2 and the source of MOSFET Q5. The gate of MOSFET Q5 is connected to chip U8 through resistors R83 and R80 connected in series. Diode D16 is connected in parallel with resistor R83. The gate of MOSFET Q5 is also connected to the source of MOSFET Q5 through resistor R79. The source of MOSFET Q5 is also connected to the drain of MOSFET Q6, one end of capacitor C41, one end of capacitor C45, one end of capacitor C44, one end of capacitor C42, and chip U8. The other ends of capacitors C41, C45, C44, and C42 are connected to the cathode of diode D14. The cathode of diode D14 is also connected to chip U8. The anode of diode D14 is connected to one end of resistor R62. The other end of resistor R62 is connected to one end of capacitor C40, one end of resistor R49, and chip U8. The other end of resistor R49 is connected to resistor R14, and the other end of capacitor C40 is connected to chip U8 and PFC oscillation circuit. Capacitor C39 is connected in parallel with capacitor C40. The drain of MOSFET Q6 is connected to the source of MOSFET Q6 through capacitor C52. The gate of MOSFET Q6 is connected to the anode of diode D15 and to the source of MOSFET Q6 through resistor R69. The cathode of diode D15 is connected to one end of resistor R70, and the other end of resistor R70 is connected to chip U8. Resistor R81 is connected in parallel with diode D15. Chip U8 is also connected to one end of resistor R66 and one end of resistor R67. The other ends of resistor R66 and the other ends of resistor R67 are connected to chip U7. The source of the MOSFET Q6 is also connected to the positive terminal of diode D11, capacitors C28, C29, and C30, chip U1, the source of MOSFET Q4, the positive terminal of diode D1, capacitors C9 and C5, the positive terminal of diode D9, capacitor C3, resistor R22, capacitor C23, chip U2, resistor R32, and capacitor C26. One pin of chip U7 is connected to pin PG2 of chip U7 via resistor R56, and capacitor C36 is connected in parallel with resistor R56; the other pin of chip U7 is connected to one end of capacitor C28, one end of capacitor C47, and one end of capacitor R68, the other end of resistor R68 is connected to resistor R14, and the other ends of capacitor C48 and capacitor C47 are connected to chip U7; chip U7 is also connected to the mains zero-crossing detection circuit. The CS pin of chip U7 is connected to resistors R46, R55, R57, and capacitor C37. The PG2 pin of chip U7 is connected to capacitors C31, C33, C37, C38, resistors R35, R57, R58, R61, the inverting input terminal of operational amplifier U4, the negative power supply terminal of operational amplifier U4, the negative power supply terminal of operational amplifier U6, capacitor C34, resistor R48, capacitor C24, and chip U5. The ZCD pin of chip U7 is connected to resistor R58, capacitor C38, and the drain of MOSFET Q7; the PDL pin of chip U7 is connected to resistor R53.

8. The switching power supply circuit of the totem bridgeless PFC according to claim 7, characterized in that: The PFC oscillation circuit includes resistor R24, diode D10, capacitor C22, resistor R25, capacitor C21, resistor R30, resistor R29, resistor R28, capacitor C25, resistor R52, and chip U3. One end of resistor R24 ​​is connected to the positive terminal of diode D10, the negative terminal of diode D10 is connected to one end of capacitor C22 and chip U3, and the other end of capacitor C22 is connected to the ACLO pin of chip U3. The other end of resistor R24 ​​is connected to one end of resistor R25, chip U3 and one end of capacitor C21. The other end of resistor R25 is connected to resistor R14. The other end of capacitor C21 is connected to the source of MOSFET Q6. One end of resistor R30 is connected to chip U3, and the other end of resistor R30 is connected to the PWH pin of chip U5 and chip U7; one end of resistor R29 is connected to chip U3, and the other end of resistor R29 is connected to the PWL pin of chip U5 and one end of resistor R52 is connected to chip U7. One pin of chip U3 is connected to the 5V power supply terminal of chip U5, and is also connected to the other pin of chip U3 and one end of capacitor C25. The other end of capacitor C25 is connected to chip U3 and one end of resistor R28. The other end of resistor R28 is connected to chip U3. The chip U3, resistor R28, and capacitor C25 are all connected to the source of MOSFET Q6; the PWH1 pin of chip U3 is connected to resistor R21; the PWL1 pin of chip U3 is connected to resistor R23; and the ACLO pin of chip U3 is connected to the source of MOSFET Q1 and the source of MOSFET Q2.

9. The switching power supply circuit of the totem bridgeless PFC according to claim 8, characterized in that: The mains zero-crossing detection circuit includes resistors R33, R65, R63, capacitors C43, R64, R71, R72, R73, capacitors C50, R78, R74, R75, R76, capacitor C49, and resistor R77. One end of resistor R33 is connected to the drain of MOSFET Q1, and the other end of resistor R33 is connected to pin PG2 of chip U7 through resistors R65, R63 and R64 connected in series. Capacitor C43 is connected in parallel with resistor R64 and is also connected to pin FB of chip U7. One end of resistor R71 is connected to one end of common mode inductor LF2, and the other end of resistor R71 is connected to pin PG2 of chip U7 through resistors R72, R73 and R78 connected in series. Capacitor C50 is connected in parallel with resistor R78 and is also connected to pin LVS1 of chip U7. One end of resistor R74 is connected to the other end of common-mode inductor LF2. The other end of resistor R74 is connected to pin PG2 of chip U7 through resistors R75, R76 and R77 connected in series. Capacitor C49 is connected to resistor R77. Capacitor C49 is also connected to pin LVS2 of chip U7.

Images