A PC power supply circuit

Abstract

The present invention relates to the technical field of computer power supply control, and in particular to a PC power supply circuit, which includes a standby circuit, a PFC circuit, a voltage stabilizing circuit, a PWM drive circuit, a first synchronous rectifier circuit, a second synchronous rectifier circuit and a monitoring circuit, wherein the standby circuit is electrically connected to the voltage stabilizing circuit, the PFC circuit, the PWM drive circuit and the monitoring circuit respectively, the PWM drive circuit is electrically connected to the first synchronous rectifier circuit, and the first synchronous rectifier circuit is electrically connected to the second synchronous rectifier circuit. The present invention has a novel structure and an ingenious design, and can output various voltages to supply power to the PC power supply, thereby effectively improving the conversion efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of computer power supply control, in particular to a PC power supply circuit. Background Art

[0002] PC power supply is a device that converts AC energy into DC energy and supplies power to host accessories. There is loss in this energy conversion process, and one indicator to measure the loss is conversion efficiency. Conversion efficiency is the ratio of power supply output power to input power, or specifically, the ratio of the sum of each group of DC output power to input active power. Ideally, the power supply can convert all AC energy into DC output without dissipation, but in reality, switching power supplies still have considerable losses, so conversion efficiency has become an important indicator to measure the performance of switching power supplies. Therefore, it is very necessary to improve the conversion efficiency of the power supply. Summary of the invention

[0003] In view of the problems of the prior art, the present invention provides a PC power supply circuit with a novel structure and ingenious design, which can output various voltages to supply power to the PC and effectively improve the conversion efficiency.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0005] A PC power supply circuit provided by the present invention comprises a standby circuit, a PFC circuit, a voltage stabilizing circuit, a PWM drive circuit, a first synchronous rectifier circuit, a second synchronous rectifier circuit and a monitoring circuit, wherein the standby circuit is electrically connected to the voltage stabilizing circuit, the PFC circuit, the PWM drive circuit and the monitoring circuit respectively, the PWM drive circuit is electrically connected to the first synchronous rectifier circuit, and the first synchronous rectifier circuit is electrically connected to the second synchronous rectifier circuit.

[0006] Wherein, the standby circuit includes a power management chip U3 and a winding T3.

[0007] The PFC circuit includes a rectifier bridge BD1, an inductor coil L1, a thermistor TH1, a diode D11, a diode D21, a resistor R7, a resistor R11, a MOS tube Q1, a switch tube Q8, a switch tube Q9, a resistor R25, a resistor R28, a resistor R32, a capacitor C2, a resistor R15, a resistor R18, a capacitor C3 and a capacitor C4. The rectifier bridge BD1 is connected to one end of the capacitor C3, one end of the resistor R7, an anode of the diode D21 and one end of the inductor coil L1. The other end of the inductor coil L1 is connected to the anode of the diode D11. The cathode of the diode D11 and the cathode of the diode D21 are both connected to one end of the thermistor TH1. The other end of the sensitive resistor TH1 is connected to the standby circuit and the capacitor C2 respectively; the other end of the resistor R7 is connected to one end of the resistor R11, and the other end of the resistor R11 is grounded; the base of the switch tube Q8 and the base of the switch tube Q9 are both connected to one end of the resistor R25, the collector of the switch tube Q8 is connected to the voltage stabilizing circuit and one end of the capacitor C4, the emitter of the switch tube Q8 is connected to one end of the resistor R28 and the emitter of the switch tube Q9 respectively, the other end of the resistor R28 is connected to one end of the resistor R32 and the gate of the MOS tube Q1 respectively, and the other end of the resistor R32 is connected to the source of the MOS tube Q1, the other end of the capacitor C4 and the collector of the switch tube Q9 respectively.

[0008] The PWM driving circuit includes a PWM controller U2, a switch tube Q4, a switch tube Q5, a resistor R33, a resistor R36, a resistor R37, a resistor R38, a capacitor C20, a capacitor C21, a MOS tube Q2, a MOS tube Q3, a diode D3, a winding T2, a capacitor C14, a diode D6, a resistor R17, a resistor R16 and a winding T1; the PWM controller U2 is connected to the base of the switch tube Q4 and the base of the switch tube Q5, the collector of the switch tube Q4 is connected to the voltage stabilizing circuit, the emitter of the switch tube Q4 is connected to the emitter of the switch tube Q5, the emitter of the switch tube Q4 and the emitter of the switch tube Q5 are both connected to one end of the resistor R37 and one end of the capacitor C21, the other end of the resistor R37 is respectively connected to the resistor R38 and the gate of the MOS tube Q3, the source of the MOS tube Q3, the other end of the resistor R38 and one end of the resistor R36 are all connected. The MOS transistor Q3 is connected to one end of the primary side of the winding T2, the drain of the MOS transistor Q3 is connected to the anode of the diode D3 and the primary side of the winding T1, the cathode of the diode D3 is connected to the FPC circuit, the secondary side of the winding T2 is respectively connected to one end of the capacitor C14, the primary side of the winding T1, one end of the resistor R17, the cathode of the diode D6 and the source of the MOS transistor Q2, the source of the MOS transistor Q2 is connected to the primary side of the winding T1, the other end of the capacitor C14 is connected to one end of the resistor R16, the other end of the resistor R16 and the other end of the resistor R17 are both connected to the gate of the MOS transistor Q2, and the drain of the MOS transistor Q2 is connected to the FPC circuit.

[0009] The first synchronous rectification circuit includes a MOS transistor Q11, a MOS transistor Q12, a capacitor C26, a resistor R39, a capacitor C11, a resistor R19, a capacitor C13, a resistor R21, an inductor L71, an inductor L72, a diode D5, a capacitor C16, a capacitor C5, an inductor L7, an inductor L5 and a capacitor C12; the gate of the MOS transistor Q11, the gate of the MOS transistor Q12, one end of the capacitor C26, the drain of the MOS transistor Q12, the drain of the MOS transistor Q11, one end of the capacitor C13 and one end of the inductor L71 are all connected to the PWM drive circuit, the other end of the capacitor C26 is connected to one end of the resistor R39, the other end of the resistor R39 and the source of the MOS transistor Q12 are all connected to the source of the MOS transistor Q11, the source of the MOS transistor Q11 is connected to one end of the capacitor C11 , the cathode of diode D5, the other end of capacitor C11 is connected to one end of resistor R19, the other end of resistor R19 is connected to the anode of diode D5 and one end of inductor L72, the cathode of diode D5 is connected to one end of resistor R21, the other end of resistor R21 is connected to the other end of capacitor C13, the other end of inductor L71 is connected to one end of capacitor C16, one end of inductor L5 and one end of inductor L7, the other end of inductor L5 is connected to the second synchronous rectification circuit, the other end of capacitor C16 is connected to one end of capacitor C5 and the cathode of diode D5, the other end of capacitor C5 is connected to the other end of inductor L72, the other end of inductor L7 is connected to one end of capacitor C12, and the common end connected to capacitor C12, capacitor C16 and capacitor C5 is grounded.

[0010] The voltage stabilizing circuit includes a capacitor C47, a resistor R303, a switch tube Q7, a voltage stabilizing diode ZD1, a capacitor C19 and a capacitor C39. The collector of the switch tube Q7 is respectively connected to one end of the resistor R303, one end of the capacitor C47 and the standby circuit. The base of the switch tube Q7 is connected to the cathode of the voltage stabilizing diode ZD1. The anode of the voltage stabilizing diode ZD1 is grounded. The capacitor C19 is connected in parallel with the voltage stabilizing diode ZD1. One end of the capacitor C39 is connected to the emitter of the switch tube Q7. The other end of the capacitor C39 is grounded.

[0011] The second synchronous rectification circuit includes an integrated IC chip U8, a switch tube Q501, a switch tube Q502, an inductor L4, a diode D501, a switch tube Q601, a switch tube Q602, an inductor L3, a diode D601, a resistor R505, a capacitor C501, a resistor R610, a resistor R607, a resistor R605 and a capacitor C601. The UGATE1 pin and the PHASE1 pin of the integrated IC chip U8 are both connected to the gate of the switch tube Q501. The drain of Q501 is connected to one end of the resistor R505, the other end of the resistor R505 is connected to the OCSET1 pin of the integrated IC chip U8, the source of the switch tube Q501 and the drain of the switch tube Q502 are both connected to one end of the inductor L4, the other end of the inductor L4 is connected to one end of the resistor R510, the other end of the resistor R510 is connected to one end of the resistor R507, the other end of the resistor R507 is grounded, the capacitor C501 is connected to the resistor R505 The source of the switch tube Q502 is grounded, and the gate of the switch tube Q502 is connected to the LGATE1 pin of the integrated IC chip U8; the UGATE2 pin and the PHASE2 pin of the integrated IC chip U8 are both connected to the gate of the switch tube Q601, the LGATE2 pin of the integrated IC chip U8 is connected to the gate of the switch tube Q602, the drain of the switch tube Q601 is connected to one end of the resistor R605, and the other end of the resistor R605 is connected to the integrated IC chip U8. 8, the capacitor C601 is connected to the OCSET2 pin of the switching tube Q601, the capacitor C601 is connected in parallel with the resistor R605, the source of the switching tube Q601 and the drain of the switching tube Q602 are both connected to one end of the inductor L3, the other end of the inductor L3 is connected to one end of the resistor R610, the other end of the resistor R610 is connected to one end of the resistor R607, the other end of the resistor R607 is grounded, the source of the switching tube Q602 is grounded, and one end of the resistor R605 is connected to the first synchronous rectification circuit.

[0012] The monitoring circuit includes a power management chip U6, and the model of the power management chip U6 is GR8313.

[0013] Beneficial effects of the present invention:

[0014] The invention has a novel structure and an ingenious design, and can output various voltages to supply power to a PC, thereby effectively improving conversion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The figure is a schematic diagram of the structure of a PC power supply circuit of the present invention.

[0016] Figure 2It is a structural schematic diagram of the standby circuit of the present invention.

[0017] Figure 3 It is a structural schematic diagram of the PFC circuit of the present invention.

[0018] Figure 4 It is a schematic structural diagram of the voltage stabilizing circuit of the present invention.

[0019] Figure 5 It is a structural schematic diagram of the PWM drive circuit of the present invention.

[0020] Figure 6 It is a structural schematic diagram of the first synchronous rectification circuit of the present invention.

[0021] Figure 7 It is a schematic diagram of the structure of the monitoring circuit of the present invention.

[0022] Figure 8 It is a structural schematic diagram of a second synchronous rectification circuit of the present invention.

[0023] exist Figures 1 to 8 Reference numerals in the drawings include:

[0024] 1—Standby circuit 2—PFC circuit 3—Voltage stabilization circuit

[0025] 4—PWM drive circuit 5—first synchronous rectification circuit 6—monitoring circuit

[0026] 7—Second synchronous rectification circuit. DETAILED DESCRIPTION

[0027] In order to facilitate the understanding of those skilled in the art, the present invention is further described below in conjunction with the embodiments and drawings, and the contents mentioned in the embodiments are not intended to limit the present invention. The present invention is described in detail below in conjunction with the drawings.

[0028] A PC power supply circuit, such as Figures 1 to 8As shown, it includes a standby circuit 1, a PFC circuit 2, a voltage stabilizing circuit 3, a PWM drive circuit 4, a first synchronous rectifier circuit 5, a second synchronous rectifier circuit 7 and a monitoring circuit 6. The standby circuit 1 is electrically connected to the voltage stabilizing circuit 3, the PFC circuit 2, the PWM drive circuit 4 and the monitoring circuit 6 respectively, the PWM drive circuit 4 is electrically connected to the first synchronous rectifier circuit 5, and the first synchronous rectifier circuit 5 is electrically connected to the second synchronous rectifier circuit 7. Specifically, the embodiment of the present invention has a novel structure and an ingenious design. The PFC circuit 2 improves the power factor and transmits the voltage to the standby circuit 1. The 380V voltage processed by the PFC circuit 2 is used as the primary side energy source of the standby circuit 1, and then the output value is output to the voltage stabilizing circuit 3 after rectification by the standby circuit 1. The voltage output by the standby circuit 1 is stabilized by the voltage stabilizing circuit 3. The monitoring circuit 6 is connected to the voltage stabilizing circuit 3, the PWM driving circuit 4 and the second synchronous rectification circuit 7. The PWM driving circuit 4 is connected to the PFC circuit 2. The PWM driving circuit 4 sends a PWN in signal and then transmits it to the first synchronous rectification circuit 5. The first synchronous rectification circuit 5 outputs 12V and -12V voltages after rectification. The second synchronous rectification circuit 7 outputs 5V and 3.3V voltages after rectification. The monitoring circuit 6 monitors each circuit of the embodiment of the present invention and can play a protective role. The embodiment of the present invention realizes the output of various voltages to supply power to the PC power supply, effectively improves the conversion efficiency, can save energy, and save electricity bills for users.

[0029] In the PC power supply circuit described in this embodiment, the standby circuit 1 includes a power management chip U3 and a winding T3. Specifically, the model of the power management chip U3 is EM8564A, and the standby circuit 1 as a whole adopts a single-ended reaction-type architecture, outputs 5V / 2.5A, and the 380V voltage processed by the PFC circuit 2 is used as the primary side energy source of the standby circuit 1. By adding the winding T3, the Vcc OUT is output after rectification and output to the voltage stabilizing circuit 3 as the primary side working voltage.

[0030] In the PC power supply circuit described in the present embodiment, the PFC circuit 2 includes a rectifier bridge BD1, an inductor coil L1, a thermistor TH1, a diode D11, a diode D21, a resistor R7, a resistor R11, a MOS tube Q1, a switch tube Q8, a switch tube Q9, a resistor R25, a resistor R28, a resistor R32, a capacitor C2, a resistor R15, a resistor R18, a capacitor C3 and a capacitor C4. The rectifier bridge BD1 is connected to one end of the capacitor C3, one end of the resistor R7, an anode of the diode D21 and one end of the inductor coil L1. The other end of the inductor coil L1 is connected to the anode of the diode D11. The cathode of the diode D11 and the cathode of the diode D21 are both connected to the cathode of the thermistor TH1. The other end of the thermistor TH1 is connected to the standby circuit 1 and the capacitor C2 respectively; the other end of the resistor R7 is connected to one end of the resistor R11, and the other end of the resistor R11 is grounded; the base of the switch tube Q8 and the base of the switch tube Q9 are both connected to one end of the resistor R25, the collector of the switch tube Q8 is connected to the voltage stabilizing circuit 3 and one end of the capacitor C4, the emitter of the switch tube Q8 is respectively connected to one end of the resistor R28 and the emitter of the switch tube Q9, the other end of the resistor R28 is respectively connected to one end of the resistor R32 and the gate of the MOS tube Q1, and the other end of the resistor R32 is respectively connected to the source of the MOS tube Q1, the other end of the capacitor C4 and the collector of the switch tube Q9.

[0031] Specifically, the PFC circuit 2 works. When the MOS tube Q1 is turned on, current flows through the inductor L1. Before the inductor L1 is not saturated, the current increases linearly, and the electric energy is stored in the inductor L1 in the form of magnetic energy. At this time, the diode D11 is turned off, and the capacitor C2 is discharged to maintain the output voltage. When the MOS tube Q1 is turned off, self-induced electromotive force is generated at both ends of the inductor L1 to keep the current direction unchanged. The self-induced electromotive force is connected in series with the power supply VIN, and the capacitor C2 and the load are charged through the diode D11.

[0032] The function of the diode D21 is that when the computer PC is turned on and the voltage of the PFC circuit 2 is not fully established, the 300V pulsating high voltage rectified by the rectifier bridge BD1 is connected to the FPC OUT pin for output through the diode D21; if the PFC circuit 2 is turned off due to other reasons, the diode D21 is used for freewheeling; the capacitor C3 is used for correction of the PFC circuit 2 and can accurately adjust the PF value to be greater than 0.9; the resistor R7 and the resistor R11 can be used as a detection circuit for the input voltage and can set the range value of the input voltage; the resistor R15 and the resistor R18 can be used as a detection circuit for the output voltage and can set the required output voltage. The resistor R25, the resistor R28, the switch tube Q8 and the switch tube Q9 constitute a PFC drive circuit, and the drive signal is transmitted through a push-pull circuit composed of the resistor R25, the resistor R28, the switch tube Q8 and the switch tube Q9, which can enhance the drive capability.

[0033] A PC power supply circuit described in this embodiment, the PWM drive circuit 4 includes a PWM controller U2, a switch tube Q4, a switch tube Q5, a resistor R33, a resistor R36, a resistor R37, a resistor R38, a capacitor C20, a capacitor C21, a MOS tube Q2, a MOS tube Q3, a diode D3, a winding T2, a capacitor C14, a diode D6, a resistor R17, a resistor R16 and a winding T1; the PWM controller U2 is connected to the base of the switch tube Q4 and the base of the switch tube Q5, the collector of the switch tube Q4 is connected to the voltage stabilizing circuit 3, the emitter of the switch tube Q4 is connected to the emitter of the switch tube Q5, the emitter of the switch tube Q4 and the emitter of the switch tube Q5 are both connected to one end of the resistor R37 and one end of the capacitor C21, the other end of the resistor R37 is respectively connected to the resistor R38 and the gate of the MOS tube Q3, the source of the MOS tube Q3, the other end of the resistor R38 and the resistor One end of R36 is connected to one end of the resistor R33, the other end of the resistor R36 is connected to one end of the capacitor C20, the other end of the capacitor C20 is connected to the other end of the resistor R33 and then connected to the PWM controller U2, the other end of the capacitor C21 is connected to the primary side of the winding T2, the drain of the MOS tube Q3 is connected to the anode of the diode D3 and the primary side of the winding T1, the cathode of the diode D3 is connected to the FPC circuit, the secondary side of the winding T2 is respectively connected to one end of the capacitor C14, the primary side of the winding T1, one end of the resistor R17, the cathode of the diode D6 and the source of the MOS tube Q2, the source of the MOS tube Q2 is connected to the primary side of the winding T1, the other end of the capacitor C14 is connected to one end of the resistor R16, the other end of the resistor R16 and the other end of the resistor R17 are both connected to the gate of the MOS tube Q2, and the drain of the MOS tube Q2 is connected to the FPC circuit.

[0034] Specifically, the PWM controller U2 outputs a PWM in signal, which is driven by a push-pull drive composed of switch tubes Q4 and Q5 to enhance the driving capability, drive MOS tubes Q2 and Q3, and form a dual-crystal forward circuit. Winding T2 serves as an isolation drive transformer, which divides the PWM signal into staggered conduction drive signals, so that MOS tubes Q2 and Q3 are respectively turned on in the upper and lower half cycles, and the primary inductance of winding T1 forms a reciprocating high-frequency current loop, thereby converting the DC high voltage into an AC high-frequency voltage, realizing the function of converting DC to AC. Diodes D3 and D6 are clamping diodes, which generate The peaks are reduced or eliminated, which reduces the stress of MOS tube Q2 and MOS tube Q3 and helps to suppress EMI; the resistor R33, the resistor R36 and the capacitor C20 form a power detection circuit on the primary side. The current flowing through the main circuit is detected by the resistor R36 and converted into a voltage signal. After attenuation by the resistor R33 and filtering by the capacitor C20, a relatively stable DC voltage is generated. The voltage increases with the increase of input power. When it exceeds the set voltage, when the signal is detected, the internal judgment is overcurrent and the PFC circuit 2 and the PWM signal are turned off to achieve the overcurrent protection function.

[0035] In the PC power supply circuit described in this embodiment, the first synchronous rectification circuit 5 includes a MOS transistor Q11, a MOS transistor Q12, a capacitor C26, a resistor R39, a capacitor C11, a resistor R19, a capacitor C13, a resistor R21, an inductor L71, an inductor L72, a diode D5, a capacitor C16, a capacitor C5, an inductor L7, an inductor L5 and a capacitor C12; the gate of the MOS transistor Q11, the gate of the MOS transistor Q12, one end of the capacitor C26, the drain of the MOS transistor Q12, the drain of the MOS transistor Q11, one end of the capacitor C13 and one end of the inductor L71 are all connected to the PWM drive circuit 4, the other end of the capacitor C26 is connected to one end of the resistor R39, the other end of the resistor R39 and the source of the MOS transistor Q12 are all connected to the source of the MOS transistor Q11, and the source of the MOS transistor Q11 is connected to the gate of the MOS transistor Q12. One end of capacitor C11 is connected to the cathode of diode D5, the other end of capacitor C11 is connected to one end of resistor R19, the other end of resistor R19 is connected to the anode of diode D5 and one end of inductor L72, the cathode of diode D5 is connected to one end of resistor R21, the other end of resistor R21 is connected to the other end of capacitor C13, the other end of inductor L71 is connected to one end of capacitor C16, one end of inductor L5 and one end of inductor L7, the other end of inductor L5 is connected to the second synchronous rectification circuit 7, the other end of capacitor C16 is connected to one end of capacitor C5 and the cathode of diode D5, the other end of capacitor C5 is connected to the other end of inductor L72, the other end of inductor L7 is connected to one end of capacitor C12, and the common end connected to capacitor C12, capacitor C16 and capacitor C5 is grounded.

[0036] Specifically, the gate of the MOS transistor Q11, the gate of the MOS transistor Q12, one end of the capacitor C26, the drain of the MOS transistor Q12, the drain of the MOS transistor Q11, one end of the capacitor C13 and one end of the inductor L71 are all connected to the secondary side of the winding T1. By winding on the winding T1, the winding T1 is connected to the gates of the MOS transistor Q11 and the MOS transistor Q12, and is turned on in the upper and lower half cycles respectively. By means of autocoupling, the IC required for the other-excitation drive is reduced, and the physical space occupied by the design is reduced. The MOS transistor is used to replace the conventional diode rectification, which greatly reduces the damage caused by the diode voltage drop at the moment of conduction, improves efficiency, and can also reduce the size of the radiator. Among them, the inductor L71 and the inductor L72 are used as chokes, and the inductor L7, the capacitor C12 and the capacitor C16 are used for filtering.

[0037] In the PC power supply circuit described in this embodiment, the voltage stabilizing circuit 3 includes a capacitor C47, a resistor R303, a switch tube Q7, a voltage stabilizing diode ZD1, a capacitor C19 and a capacitor C39, the collector of the switch tube Q7 is respectively connected to one end of the resistor R303, one end of the capacitor C47 and the standby circuit 1, the base of the switch tube Q7 is connected to the cathode of the voltage stabilizing diode ZD1, the anode of the voltage stabilizing diode ZD1 is grounded, the capacitor C19 is connected in parallel with the voltage stabilizing diode ZD1, one end of the capacitor C39 is connected to the emitter of the switch tube Q7, and the other end of the capacitor C39 is grounded. Specifically, the standby circuit 1 outputs Vcc OUT after rectification as Vcc IN and is input to the voltage stabilizing circuit 3, and the voltage is stabilized by the voltage stabilizing circuit 3. The base of the switch tube Q7 is connected to the PS-ON signal. In the low level state, the switch tube Q7 is turned on, and the voltage stabilizing diode ZD1 clamps the voltage at 18V, so that the operating voltage does not exceed the rated voltage, so that the primary side signal part can work stably.

[0038] In the PC power supply circuit described in this embodiment, the second synchronous rectification circuit 7 includes an integrated IC chip U8, a switch tube Q501, a switch tube Q502, an inductor L4, a diode D501, a switch tube Q601, a switch tube Q602, an inductor L3, a diode D601, a resistor R505, a capacitor C501, a resistor R610, a resistor R607, a resistor R605 and a capacitor C601, the UGATE1 pin and the PHASE1 pin of the integrated IC chip U8 are both connected to the gate of the switch tube Q501, and the drain of the switch tube Q501 is connected to one end of the resistor R505. , the other end of the resistor R505 is connected to the OCSET1 pin of the integrated IC chip U8, the source of the switch tube Q501 and the drain of the switch tube Q502 are both connected to one end of the inductor L4, the other end of the inductor L4 is connected to one end of the resistor R510, the other end of the resistor R510 is connected to one end of the resistor R507, the other end of the resistor R507 is grounded, the capacitor C501 is connected in parallel with the resistor R505, the source of the switch tube Q502 is grounded, and the gate of the switch tube Q502 is connected to the LGATE1 pin of the integrated IC chip U8;

[0039] The UGATE2 pin and the PHASE2 pin of the integrated IC chip U8 are both connected to the gate of the switch tube Q601, the LGATE2 pin of the integrated IC chip U8 is connected to the gate of the switch tube Q602, the drain of the switch tube Q601 is connected to one end of the resistor R605, the other end of the resistor R605 is connected to the OCSET2 pin of the integrated IC chip U8, the capacitor C601 is connected in parallel with the resistor R605, the source of the switch tube Q601 and the drain of the switch tube Q602 are both connected to one end of the inductor L3, the other end of the inductor L3 is connected to one end of the resistor R610, the other end of the resistor R610 is connected to one end of the resistor R607, the other end of the resistor R607 is grounded, the source of the switch tube Q602 is grounded, and one end of the resistor R605 is connected to the first synchronous rectification circuit 5.

[0040] Specifically, the integrated IC chip U8 is APW7159A, which integrates the output drive, protection and other circuits into one IC, reducing the package size. At the same time, the same operating frequency is used to reduce EMI interference. Among them, the switch tube Q501, the switch tube Q502, the inductor coil L4 and the diode 501 constitute a 5V synchronous rectification circuit. By replacing the diode with a MOS tube, the loss during the conduction period is greatly reduced, and the efficiency is improved; the switch tube Q601, the switch tube Q602, the inductor coil L3 and the diode D601 constitute a 3.3V synchronous rectification circuit. The overall efficiency of the two can reach more than 90%, thereby improving the conversion efficiency. Among them, the resistor R510 and the resistor R507 constitute an output voltage detection circuit, and the resistor R505 and the capacitor C501 constitute a frequency oscillation circuit, which effectively determines the operating frequency.

[0041] In the PC power supply circuit described in this embodiment, the monitoring circuit 6 includes a power management chip U6, and the model of the power management chip U6 is GR8313. Specifically, GR8313 is used as the monitoring circuit 6 on the output side to monitor the voltages of 12V, 5V, 3.3V and -12V respectively, and the monitoring information of each voltage is summarized to the 5th and 6th pins of the power management chip U6, and is also used for short circuit detection function.

[0042] Pin 4 of the power management chip U6 is the power on / off signal of PS-ON, which is valid at low level.

[0043] Pin 1 of the power management chip U6 collects the PG power-on signal as the PG input signal, and pin 8 of the power management chip U6 serves as the PG output signal to ensure that the PG signal is within the range of 100-500ms.

[0044] Among them, resistor R67, resistor R71, resistor R78 and resistor R79 are used as 12V output voltage sampling to ensure that the output voltage is between 11.4V and 12.6V.

[0045] Pin 3 of the power management chip U6 is used as the switch and protection output signal. The signal is transmitted to the primary side through an optocoupler, and various functions are realized by turning on or off the primary side VCC.

[0046] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention is disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with the profession can make some changes or modifications to equivalent embodiments of equivalent changes by using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent changes and modifications made to the above embodiments according to the technology of the present invention are within the scope of the technical solution of the present invention without departing from the content of the technical solution of the present invention.

Claims

1. A PC power supply circuit, characterized in that: The invention comprises a standby circuit, a PFC circuit, a voltage stabilizing circuit, a PWM driving circuit, a first synchronous rectifier circuit, a second synchronous rectifier circuit and a monitoring circuit, wherein the standby circuit is electrically connected to the voltage stabilizing circuit, the PFC circuit, the PWM driving circuit and the monitoring circuit respectively, the PWM driving circuit is electrically connected to the first synchronous rectifier circuit, and the first synchronous rectifier circuit is electrically connected to the second synchronous rectifier circuit; The standby circuit includes a power management chip U3 and a winding T3; the model of the power management chip U3 is EM8564A; The PFC circuit includes a rectifier bridge BD1, an inductor coil L1, a thermistor TH1, a diode D11, a diode D21, a resistor R7, a resistor R11, a MOS tube Q1, a switch tube Q8, a switch tube Q9, a resistor R25, a resistor R28, a resistor R32, a capacitor C2, a resistor R15, a resistor R18, a capacitor C3 and a capacitor C4. The rectifier bridge BD1 is connected to one end of the capacitor C3, one end of the resistor R7, an anode of the diode D21 and one end of the inductor coil L1. The other end of the inductor coil L1 is connected to the anode of the diode D11. The cathode of the diode D11 and the cathode of the diode D21 are both connected to one end of the thermistor TH1. The other end of the resistor TH1 is connected to the standby circuit and the capacitor C2 respectively; the other end of the resistor R7 is connected to one end of the resistor R11, and the other end of the resistor R11 is grounded; the base of the switch tube Q8 and the base of the switch tube Q9 are both connected to one end of the resistor R25, the collector of the switch tube Q8 is connected to the voltage stabilizing circuit and one end of the capacitor C4, the emitter of the switch tube Q8 is connected to one end of the resistor R28 and the emitter of the switch tube Q9 respectively, the other end of the resistor R28 is connected to one end of the resistor R32 and the gate of the MOS tube Q1 respectively, and the other end of the resistor R32 is connected to the source of the MOS tube Q1, the other end of the capacitor C4 and the collector of the switch tube Q9 respectively; The PWM driving circuit includes a PWM controller U2, a switch tube Q4, a switch tube Q5, a resistor R33, a resistor R36, a resistor R37, a resistor R38, a capacitor C20, a capacitor C21, a MOS tube Q2, a MOS tube Q3, a diode D3, a winding T2, a capacitor C14, a diode D6, a resistor R17, a resistor R16 and a winding T1; the PWM controller U2 is connected to the base of the switch tube Q4 and the base of the switch tube Q5, the collector of the switch tube Q4 is connected to the voltage stabilizing circuit, the emitter of the switch tube Q4 is connected to the emitter of the switch tube Q5, the emitter of the switch tube Q4 and the emitter of the switch tube Q5 are both connected to one end of the resistor R37 and one end of the capacitor C21, the other end of the resistor R37 is respectively connected to the resistor R38 and the gate of the MOS tube Q3, the source of the MOS tube Q3, the other end of the resistor R38 and one end of the resistor R36 are all connected to the resistor One end of the resistor R33 is connected, the other end of the resistor R36 is connected to one end of the capacitor C20, the other end of the capacitor C20 is connected to the other end of the resistor R33 and then connected to the PWM controller U2, the other end of the capacitor C21 is connected to the primary side of the winding T2, the drain of the MOS tube Q3 is connected to the anode of the diode D3 and the primary side of the winding T1, the cathode of the diode D3 is connected to the FPC circuit, the secondary side of the winding T2 is respectively connected to one end of the capacitor C14, the primary side of the winding T1, one end of the resistor R17, the cathode of the diode D6 and the source of the MOS tube Q2, the source of the MOS tube Q2 is connected to the primary side of the winding T1, the other end of the capacitor C14 is connected to one end of the resistor R16, the other end of the resistor R16 and the other end of the resistor R17 are both connected to the gate of the MOS tube Q2, and the drain of the MOS tube Q2 is connected to the FPC circuit; The first synchronous rectification circuit includes a MOS transistor Q11, a MOS transistor Q12, a capacitor C26, a resistor R39, a capacitor C11, a resistor R19, a capacitor C13, a resistor R21, an inductor L71, an inductor L72, a diode D5, a capacitor C16, a capacitor C5, an inductor L7, an inductor L5 and a capacitor C12; the gate of the MOS transistor Q11, the gate of the MOS transistor Q12, one end of the capacitor C26, the drain of the MOS transistor Q12, the drain of the MOS transistor Q11, one end of the capacitor C13 and one end of the inductor L71 are all connected to the PWM drive circuit, the other end of the capacitor C26 is connected to one end of the resistor R39, the other end of the resistor R39 and the source of the MOS transistor Q12 are all connected to the source of the MOS transistor Q11, the source of the MOS transistor Q11 is connected to one end of the capacitor C ... the gate of the MOS transistor Q12, the one end of the capacitor C26, the drain of the MOS transistor Q12, the drain of the MOS transistor Q11, the one end of the capacitor C13 and the one end of the inductor L71 are all connected to the PWM drive circuit, the other end of the capacitor C The cathode of the diode D5 is connected, the other end of the capacitor C11 is connected to one end of the resistor R19, the other end of the resistor R19 is connected to the anode of the diode D5 and one end of the inductor L72, the cathode of the diode D5 is connected to one end of the resistor R21, the other end of the resistor R21 is connected to the other end of the capacitor C13, the other end of the inductor L71 is connected to one end of the capacitor C16, one end of the inductor L5 and one end of the inductor L7, the other end of the inductor L5 is connected to the second synchronous rectification circuit, the other end of the capacitor C16 is connected to one end of the capacitor C5 and the cathode of the diode D5, the other end of the capacitor C5 is connected to the other end of the inductor L72, the other end of the inductor L7 is connected to one end of the capacitor C12, and the common end connected to the capacitor C12, the capacitor C16 and the capacitor C5 is grounded; The voltage stabilizing circuit includes a capacitor C47, a resistor R303, a switch tube Q7, a voltage stabilizing diode ZD1, a capacitor C19 and a capacitor C39, the collector of the switch tube Q7 is respectively connected to one end of the resistor R303, one end of the capacitor C47 and the standby circuit, the base of the switch tube Q7 is connected to the cathode of the voltage stabilizing diode ZD1, the anode of the voltage stabilizing diode ZD1 is grounded, the capacitor C19 is connected in parallel with the voltage stabilizing diode ZD1, one end of the capacitor C39 is connected to the emitter of the switch tube Q7, and the other end of the capacitor C39 is grounded; The second synchronous rectification circuit includes an integrated IC chip U8, a switch tube Q501, a switch tube Q502, an inductor L4, a diode D501, a switch tube Q601, a switch tube Q602, an inductor L3, a diode D601, a resistor R505, a capacitor C501, a resistor R610, a resistor R607, a resistor R605 and a capacitor C601. The UGATE1 pin and the PHASE1 pin of the integrated IC chip U8 are both connected to the gate of the switch tube Q501, the drain of the switch tube Q501 is connected to one end of the resistor R505, and the resistor R505 The other end of the switch tube Q501 is connected to the OCSET1 pin of the integrated IC chip U8, the source of the switch tube Q501 and the drain of the switch tube Q502 are both connected to one end of the inductor L4, the other end of the inductor L4 is connected to one end of the resistor R510, the other end of the resistor R510 is connected to one end of the resistor R507, the other end of the resistor R507 is grounded, the capacitor C501 is connected in parallel with the resistor R505, the source of the switch tube Q502 is grounded, and the gate of the switch tube Q502 is connected to the LGATE1 pin of the integrated IC chip U8; The UGATE2 pin and the PHASE2 pin of the integrated IC chip U8 are both connected to the gate of the switch tube Q601, the LGATE2 pin of the integrated IC chip U8 is connected to the gate of the switch tube Q602, the drain of the switch tube Q601 is connected to one end of the resistor R605, the other end of the resistor R605 is connected to the OCSET2 pin of the integrated IC chip U8, the capacitor C601 is connected in parallel with the resistor R605, the source of the switch tube Q601 and the drain of the switch tube Q602 are both connected to one end of the inductor L3, the other end of the inductor L3 is connected to one end of the resistor R610, the other end of the resistor R610 is connected to one end of the resistor R607, the other end of the resistor R607 is grounded, the source of the switch tube Q602 is grounded, and one end of the resistor R605 is connected to the first synchronous rectification circuit; The monitoring circuit includes a power management chip U6, and the model of the power management chip U6 is GR8313.

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