Control circuit suitable for synchronous rectification circuit

Abstract

The control circuit suitable for the synchronous rectification circuit comprises a driving circuit and a synchronous rectification adjusting circuit. The driving circuit is responsible for controlling on and off of a power regulation switch tube M1 of the synchronous rectification circuit and providing a turn-off signal offset 1 for the synchronous rectification regulation circuit; the synchronous rectification adjusting circuit is responsible for controlling on and off of a synchronous rectification switch tube M2 of the synchronous rectification circuit. The synchronous rectification switch tube M2 is turned off preferentially before the power regulation switch tube M1 is turned on, and the synchronous rectification switch tube M2 is turned on after the power regulation switch tube M1 is turned off. According to the control circuit suitable for the synchronous rectification circuit, synchronous rectification control of the synchronous rectification circuit is achieved through logic combination of hardware circuits, the energy conversion efficiency of the synchronous rectification circuit is effectively improved, and the reliability is high.

Description

Technical Field

[0001] The invention belongs to the technology of spacecraft energy management system, and in particular relates to a control circuit suitable for a synchronous rectification circuit. Background Art

[0002] When the aircraft is operating in space, due to limited energy, the power controller is required to have the characteristics of high-efficiency conversion. Traditional power controllers use asynchronous rectification design for reliability considerations, and the circuit conversion efficiency is relatively low; civil power controllers use software algorithms to achieve synchronous rectification, which has low reliability. Summary of the invention

[0003] The object of the present invention is to provide a control circuit suitable for a synchronous rectification circuit, which improves the circuit conversion efficiency while ensuring the spatial application reliability of a power supply controller.

[0004] In order to achieve the above-mentioned purpose, the present invention provides a control circuit suitable for a synchronous rectification circuit, the synchronous rectification circuit includes a power regulation switch tube M1 and a synchronous rectification switch tube M2, and the control circuit suitable for the synchronous rectification circuit includes a drive circuit and a synchronous rectification regulation circuit; the drive circuit is responsible for controlling the on and off of the power regulation switch tube M1 of the synchronous rectification circuit, and providing a shutdown signal off1 for the synchronous rectification regulation circuit; the synchronous rectification regulation circuit is responsible for controlling the on and off of the synchronous rectification switch tube M2 of the synchronous rectification circuit; the synchronous rectification switch tube M2 is preferentially turned off before the power regulation switch tube M1 is turned on, and the synchronous rectification switch tube M2 is turned on again after the power regulation switch tube M1 is turned off.

[0005] The above control circuit is suitable for a synchronous rectification circuit, wherein the driving circuit includes a delay circuit, an amplifier circuit and a current limiting circuit; the input end of the delay circuit is connected to the square wave signal PWM1, and the output end of the delay circuit is connected to the input end of the amplifier circuit; the output end of the amplifier circuit is connected to the gate of the power regulating switch tube M1 of the synchronous rectification circuit, and provides a driving signal V for the power regulating switch tube M1 GSM1; The square wave signal PWM1 is input into the current limiting circuit, and the current limiting circuit provides a shutdown signal off1 for the synchronous rectification regulation circuit; the synchronous rectification regulation circuit includes a transformer T1, a diode D2, a diode D3, a triode Q3, a triode Q4, a triode Q5, a capacitor C1, a resistor R2, a resistor R3, a resistor R4, a resistor R5 and a resistor R6; the primary side of the transformer T1 is connected to the square wave signal PWM2; the same-name end of the secondary side of the transformer T1 is connected to one end of the resistor R2; the other end of the resistor R2 is connected to the positive electrode of the diode D2; the negative electrode of the diode D2 is connected to one end of the resistor R3; the other end of the resistor R3 is connected to the base of the triode Q3; the collector of the triode Q3 is connected to the negative electrode of the diode D2; the emitter of the triode Q3 is connected to the triode Q4 The emitter of the transistor Q4 is connected; the base of the transistor Q4 is connected to the collector of the transistor Q5; the emitter of the transistor Q5 and the collector of the transistor Q4 are both connected to the non-same-name end of the secondary side of the transformer T1, and the non-same-name end of the secondary side of the transformer T1 is connected to the source of the synchronous rectification switch tube M2 of the synchronous rectification circuit; one end of the capacitor C1 is connected to the collector of the transistor Q3, and the other end of the capacitor C1 is connected to the non-same-name end of the secondary side of the transformer T1; one end of the resistor R5 is connected to the base of the transistor Q4, and the other end of the resistor R5 is connected to the collector of the transistor Q2 of the drive circuit; one end of the resistor R4 is connected to the emitter of the transistor Q3, and the other end of the resistor R4 is connected to the gate of the synchronous rectification switch tube M2 of the synchronous rectification circuit, providing a drive signal V for the synchronous rectification switch tube M2. GSM2 ;; One end of the resistor R6 is connected to the base of the transistor Q5, and the other end of the resistor R6 is connected to the cathode of the diode D3; the anode of the diode D3 is connected to the +12V voltage.

[0006] The above-mentioned control circuit is suitable for a synchronous rectification circuit, wherein the current limiting circuit includes a transistor Q1, a transistor Q2 and a resistor R1; the collector of the transistor Q1 and the base of the transistor Q2 are both connected to the square wave signal PWM1; the base of the transistor Q1 is connected to the emitter of the transistor Q2; the emitter of the transistor Q1 is grounded; one end of the resistor R1 is connected to the emitter of the transistor Q2, and the other end of the resistor R1 is grounded.

[0007] The above control circuit is suitable for a synchronous rectification circuit, wherein the driving circuit has a sequential regulation function: the high level of the input signal PWM1 (square wave signal) of the driving circuit is regulated by the delay circuit and the driving circuit, and then the power regulating switch tube M1 is turned on after a delay of 1% to 2% duty cycle; the input signal PWM1 is regulated by the current limiting circuit to provide a low-level discharge channel for the synchronous rectification regulation circuit, so that the synchronous rectification switch tube M2 is normally turned off; the driving circuit ensures that the synchronous rectification switch tube M2 is disconnected first, and then the power regulating switch tube M1 is turned on, thereby avoiding the power regulating switch tube M1 and the synchronous rectification switch tube M2 being turned on at the same time, resulting in a circuit short circuit.

[0008] The above control circuit is suitable for a synchronous rectification circuit, wherein the driving circuit has a current limiting function: if the current in the transistor Q2 increases, causing the voltage across the resistor R1 to be greater than the base turn-on voltage of the transistor Q1, the transistor Q1 is turned on to lower the base voltage of the transistor Q2, that is, to lower the input signal PWM1, thereby achieving current limiting protection for the circuit.

[0009] The above control circuit is applicable to the synchronous rectification circuit, wherein the synchronous rectification regulation circuit has an isolation driving function: the high-frequency signal PWM2 continuously charges the capacitor C1 through the transformer T1, and when the synchronous rectification switch tube M2 is turned on, the capacitor C1 turns on the transistor Q3 through the resistor R3, and then the capacitor C1 provides a conduction voltage for the base of the synchronous rectification switch tube M2 through the transistor Q3.

[0010] The above control circuit is suitable for a synchronous rectification circuit, wherein the synchronous rectification regulation circuit has a sequential regulation function: when the power regulation switch tube M1 needs to be turned on, the transistor Q2 lowers the base voltage of the transistor Q4 through the resistor R5, and preferentially disconnects the synchronous rectification switch tube M2; when the power regulation switch tube M1 is normally turned on, the source of the synchronous rectification switch tube M2 is pulled down to zero level, then +12V can turn on the transistor Q5 through the diode D3, and lock the base voltage of the transistor Q4 to a low level, until the power regulation switch tube M1 is disconnected, and the source of the synchronous rectification switch tube M2 returns to a high level and then contacts the locked state, so as to realize that the synchronous rectification switch tube M2 is turned on after the power regulation switch tube M1 is disconnected.

[0011] Compared with the prior art, the beneficial technical effects of the present invention are:

[0012] The control circuit suitable for the synchronous rectification circuit of the present invention adopts discrete devices to realize the isolation drive of the synchronous rectification circuit and the control strategy of "first turn off and then turn on" of the synchronous rectification switch tube, that is, the synchronous rectification switch tube is preferentially turned off before the power regulation switch tube is turned on, and the synchronous rectification switch tube is turned on after the power regulation switch tube is turned off, which ensures the system reliability while effectively improving the conversion efficiency of the circuit, and is conducive to the lightweight design of the power supply controller. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The control circuit applicable to the synchronous rectification circuit of the present invention is given by the following embodiments and drawings.

[0014] Figure 1 Schematic diagram of a control circuit applicable to a synchronous rectification circuit according to an embodiment of the present invention.

[0015] Figure 2 In the embodiment of the present invention, the input signal PWM1, the high-frequency signal PWM2, and the driving signal V of the power regulating switch tube M1 are GSM1 And the driving signal V of the synchronous rectifier switch tube M2GSM2 Schematic diagram of . DETAILED DESCRIPTION

[0016] The following will be combined Figure 1-2 The control circuit applicable to the synchronous rectification circuit of the present invention is further described in detail.

[0017] Figure 1 FIG. 1 is a schematic diagram of a control circuit applicable to a synchronous rectification circuit according to an embodiment of the present invention.

[0018] See also Figure 1 The synchronous rectification circuit includes a power regulating switch tube M1, a synchronous rectification switch tube M2 and a diode D1. The drain of the power regulating switch tube M1 is connected to the source of the synchronous rectification switch tube M2, the source of the power regulating switch tube M1 is grounded, the positive electrode of the diode D1 is connected to the source of the synchronous rectification switch tube M2, the negative electrode of the diode D1 is connected to the drain of the synchronous rectification switch tube M2, the drain and source of the power regulating switch tube M1 are input ends of the synchronous rectification circuit, and are respectively connected to Vin+ and Vin- of an external power supply (i.e., input power supply), and the drain of the synchronous rectification switch tube M2 and the source of the power regulating switch tube M1 are output ends Vo+ and Vo- of the synchronous rectification circuit respectively.

[0019] like Figure 1 The control circuit applicable to the synchronous rectification circuit of this embodiment includes a driving circuit and a synchronous rectification regulation circuit; the driving circuit is responsible for controlling the on and off of the power regulation switch tube M1 of the synchronous rectification circuit, and providing a shutdown signal off1 for the synchronous rectification regulation circuit; the synchronous rectification regulation circuit is responsible for controlling the on and off of the synchronous rectification switch tube M2 of the synchronous rectification circuit.

[0020] The driving circuit includes a delay circuit, an amplifier circuit and a current limiting circuit; the input end of the delay circuit is connected to the square wave signal PWM1, and the output end of the delay circuit is connected to the input end of the amplifier circuit; the output end of the amplifier circuit is connected to the gate of the power regulating switch tube M1 of the synchronous rectification circuit, providing a driving signal V for the power regulating switch tube M1 GSM1 ; The square wave signal PWM1 is input into the current limiting circuit, and the current limiting circuit provides a shutdown signal off1 for the synchronous rectification regulation circuit.

[0021] Specifically, the current limiting circuit includes a transistor Q1, a transistor Q2 and a resistor R1; the collector of the transistor Q1 and the base of the transistor Q2 are both connected to the square wave signal PWM1; the base of the transistor Q1 is connected to the emitter of the transistor Q2; the emitter of the transistor Q1 is grounded; one end of the resistor R1 is connected to the emitter of the transistor Q2, and the other end of the resistor R1 is grounded; the collector of the transistor Q2 is connected to the synchronous rectification regulation circuit to provide a shutdown signal off1 for the synchronous rectification regulation circuit.

[0022] The synchronous rectification regulation circuit includes a transformer T1, a diode D2, a diode D3, a triode Q3, a triode Q4, a triode Q5, a capacitor C1, a resistor R2, a resistor R3, a resistor R4, a resistor R5 and a resistor R6; the primary side of the transformer T1 is connected to a square wave signal PWM2; the same-name end of the secondary side of the transformer T1 is connected to one end of the resistor R2; the other end of the resistor R2 is connected to the positive electrode of the diode D2; the negative electrode of the diode D2 is connected to one end of the resistor R3; the other end of the resistor R3 is connected to the base of the triode Q3; the collector of the triode Q3 is connected to the negative electrode of the diode D2; the emitter of the triode Q3 is connected to the emitter of the triode Q4; the base of the triode Q4 is connected to the positive electrode ... 5; the emitter of the transistor Q5 and the collector of the transistor Q4 are both connected to the non-same-name end of the secondary side of the transformer T1, and the non-same-name end of the secondary side of the transformer T1 is connected to the source of the synchronous rectification switch tube M2 of the synchronous rectification circuit; one end of the capacitor C1 is connected to the collector of the transistor Q3, and the other end of the capacitor C1 is connected to the non-same-name end of the secondary side of the transformer T1; one end of the resistor R5 is connected to the base of the transistor Q4, and the other end of the resistor R5 is connected to the collector of the transistor Q2 of the drive circuit; one end of the resistor R4 is connected to the emitter of the transistor Q3, and the other end of the resistor R4 is connected to the gate of the synchronous rectification switch tube M2 of the synchronous rectification circuit, providing a drive signal V for the synchronous rectification switch tube M2. GSM2 ;; One end of the resistor R6 is connected to the base of the transistor Q5, and the other end of the resistor R6 is connected to the cathode of the diode D3; the anode of the diode D3 is connected to the +12V voltage.

[0023] The driving circuit has a sequential control function: after the high level of the input signal PWM1 (square wave signal) of the driving circuit is regulated by the delay circuit and the driving circuit, the power regulating switch tube M1 is turned on after a delay of 1% to 2% duty cycle; the input signal PWM1 is regulated by the current limiting circuit to provide a low-level discharge channel for the synchronous rectification regulation circuit, so that the synchronous rectification switch tube M2 is normally turned off. The driving circuit ensures that the synchronous rectification switch tube M2 is disconnected first, and then the power regulating switch tube M1 is turned on, avoiding the power regulating switch tube M1 and the synchronous rectification switch tube M2 being turned on at the same time to cause a circuit short circuit.

[0024] The driving circuit has a current limiting function: if the current in the transistor Q2 increases, causing the voltage across the resistor R1 to be greater than the base turn-on voltage of the transistor Q1, the transistor Q1 is turned on to lower the base voltage of the transistor Q2, that is, to lower the input signal PWM1, thereby achieving current limiting protection for the circuit.

[0025] The synchronous rectification regulation circuit has an isolation driving function: the high-frequency signal PWM2 continuously charges the capacitor C1 through the transformer T1, and when the synchronous rectification switch tube M2 is turned on, the capacitor C1 turns on the transistor Q3 through the resistor R3, and then the capacitor C1 provides a conduction voltage for the base of the synchronous rectification switch tube M2 through the transistor Q3.

[0026] The synchronous rectification regulation circuit has a sequential regulation function: when the power regulation switch tube M1 needs to be turned on, the transistor Q2 lowers the base voltage of the transistor Q4 through the resistor R5, and preferentially disconnects the synchronous rectification switch tube M2; when the power regulation switch tube M1 is normally turned on, the S pole (source) of the synchronous rectification switch tube M2 is pulled down to zero level, then +12V can turn on the transistor Q5 through the diode D3, and lock the base voltage of the transistor Q4 to a low level, until the power regulation switch tube M1 is disconnected, and the S pole (source) of the synchronous rectification switch tube M2 returns to a high level and then contacts the locked state, so as to realize that the synchronous rectification switch tube M2 is turned on after the power regulation switch tube M1 is disconnected.

[0027] Input signal PWM1 (low frequency signal), high frequency signal PWM2, driving signal V of power regulating switch tube M1 GSM1 , the driving signal V of the synchronous rectifier switch tube M2 GSM2 like Figure 2 shown.

[0028] The control circuit of the embodiment is applicable to the synchronous rectification circuit, and realizes the synchronous rectification control of the synchronous rectification circuit through the logical combination of hardware circuits, thereby effectively improving the energy conversion efficiency of the synchronous rectification circuit and having high reliability.

[0029] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.

Claims

1. A control circuit suitable for a synchronous rectification circuit, wherein the synchronous rectification circuit comprises a power regulation switch tube M1 and a synchronous rectification switch tube M2, wherein: The control circuit suitable for the synchronous rectification circuit includes a driving circuit and a synchronous rectification regulation circuit; the driving circuit is responsible for controlling the on and off of the power regulation switch tube M1 of the synchronous rectification circuit, and providing a shutdown signal off1 for the synchronous rectification regulation circuit; The synchronous rectification regulation circuit is responsible for controlling the on and off of the synchronous rectification switch tube M2 of the synchronous rectification circuit; the synchronous rectification switch tube M2 is preferentially turned off before the power regulation switch tube M1 is turned on, and the synchronous rectification switch tube M2 is turned on after the power regulation switch tube M1 is turned off.

2. The control circuit suitable for a synchronous rectification circuit as claimed in claim 1, characterized in that: The driving circuit includes a delay circuit, an amplifier circuit and a current limiting circuit; the input end of the delay circuit is connected to the square wave signal PWM1, and the output end of the delay circuit is connected to the input end of the amplifier circuit; the output end of the amplifier circuit is connected to the gate of the power regulating switch tube M1 of the synchronous rectification circuit, providing a driving signal V for the power regulating switch tube M1 GSM1 ; The square wave signal PWM1 is input into the current limiting circuit, and the current limiting circuit provides a shutdown signal off1 for the synchronous rectification regulation circuit; The synchronous rectification regulation circuit includes a transformer T1, a diode D2, a diode D3, a triode Q3, a triode Q4, a triode Q5, a capacitor C1, a resistor R2, a resistor R3, a resistor R4, a resistor R5 and a resistor R6; the primary side of the transformer T1 is connected to a square wave signal PWM2; the same-name end of the secondary side of the transformer T1 is connected to one end of the resistor R2; the other end of the resistor R2 is connected to the positive electrode of the diode D2; the negative electrode of the diode D2 is connected to one end of the resistor R3; the other end of the resistor R3 is connected to the base of the triode Q3; the collector of the triode Q3 is connected to the negative electrode of the diode D2; the emitter of the triode Q3 is connected to the emitter of the triode Q4; the base of the triode Q4 is connected to the positive electrode ... 5; the emitter of the transistor Q5 and the collector of the transistor Q4 are both connected to the non-same-name end of the secondary side of the transformer T1, and the non-same-name end of the secondary side of the transformer T1 is connected to the source of the synchronous rectification switch tube M2 of the synchronous rectification circuit; one end of the capacitor C1 is connected to the collector of the transistor Q3, and the other end of the capacitor C1 is connected to the non-same-name end of the secondary side of the transformer T1; one end of the resistor R5 is connected to the base of the transistor Q4, and the other end of the resistor R5 is connected to the collector of the transistor Q2 of the drive circuit; one end of the resistor R4 is connected to the emitter of the transistor Q3, and the other end of the resistor R4 is connected to the gate of the synchronous rectification switch tube M2 of the synchronous rectification circuit, providing a drive signal V for the synchronous rectification switch tube M2. GSM2 ;; One end of the resistor R6 is connected to the base of the transistor Q5, and the other end of the resistor R6 is connected to the cathode of the diode D3; the anode of the diode D3 is connected to the +12V voltage.

3. The control circuit suitable for a synchronous rectification circuit as claimed in claim 2, characterized in that: The current limiting circuit includes a transistor Q1, a transistor Q2 and a resistor R1; the collector of the transistor Q1 and the base of the transistor Q2 are both connected to the square wave signal PWM1; the base of the transistor Q1 is connected to the emitter of the transistor Q2; the emitter of the transistor Q1 is grounded; one end of the resistor R1 is connected to the emitter of the transistor Q2, and the other end of the resistor R1 is grounded.

4. The control circuit suitable for a synchronous rectification circuit as claimed in claim 2, characterized in that: The driving circuit has a sequential control function: the high level of the input signal PWM1 (square wave signal) of the driving circuit is regulated by the delay circuit and the driving circuit, and then the power regulating switch tube M1 is turned on after a delay of 1% to 2% duty cycle; the input signal PWM1 is regulated by the current limiting circuit to provide a low-level discharge channel for the synchronous rectification regulation circuit, so that the synchronous rectification switch tube M2 is normally turned off; the driving circuit ensures that the synchronous rectification switch tube M2 is disconnected first, and then the power regulating switch tube M1 is turned on, thereby avoiding the power regulating switch tube M1 and the synchronous rectification switch tube M2 being turned on at the same time to cause a circuit short circuit.

5. The control circuit suitable for a synchronous rectification circuit as claimed in claim 2, characterized in that: The driving circuit has a current limiting function: if the current in the transistor Q2 increases, causing the voltage across the resistor R1 to be greater than the base turn-on voltage of the transistor Q1, the transistor Q1 is turned on to lower the base voltage of the transistor Q2, that is, to lower the input signal PWM1, thereby achieving current limiting protection for the circuit.

6. The control circuit suitable for a synchronous rectification circuit as claimed in claim 2, characterized in that: The synchronous rectification regulation circuit has an isolation driving function: the high-frequency signal PWM2 continuously charges the capacitor C1 through the transformer T1. When the synchronous rectification switch tube M2 is turned on, the capacitor C1 turns on the transistor Q3 through the resistor R3, and then the capacitor C1 provides a conduction voltage for the base of the synchronous rectification switch tube M2 through the transistor Q3.

7. The control circuit suitable for a synchronous rectification circuit as claimed in claim 2, characterized in that: The synchronous rectification regulation circuit has a sequential regulation function: when the power regulation switch tube M1 needs to be turned on, the transistor Q2 lowers the base voltage of the transistor Q4 through the resistor R5, and preferentially disconnects the synchronous rectification switch tube M2; when the power regulation switch tube M1 is turned on normally, the source of the synchronous rectification switch tube M2 is pulled down to zero level, then +12V can turn on the transistor Q5 through the diode D3, and lock the base voltage of the transistor Q4 to a low level until the power regulation switch tube M1 is disconnected, and the source of the synchronous rectification switch tube M2 returns to a high level and then contacts the locked state, so that the synchronous rectification switch tube M2 is turned on after the power regulation switch tube M1 is disconnected.

Images