CN203788180U

CN203788180U - Drive circuit for switching power supply

Info

Publication number: CN203788180U
Application number: CN201320885542.2U
Authority: CN
Inventors: 郑德保; 蒋霞; 赵小华
Original assignee: JIANGSU JIAYU NEW POWER TECHNOLOGY Co Ltd
Current assignee: JIANGSU JIAYU NEW POWER TECHNOLOGY Co Ltd
Priority date: 2013-12-31
Filing date: 2013-12-31
Publication date: 2014-08-20
Anticipated expiration: 2023-12-31

Abstract

The utility model discloses a drive circuit for a switching power supply. The drive circuit comprises a first input end, a second input end, a transformer, from first to third capacitors, from first to ninth resistors, from first to sixth diodes, a first triode, a second triode, a first field effect transistor, a second field effect transistor, a positive output terminal and a negative output terminal. Two capacitors are additionally provided based on a conventional medium-high power isolated bridge-type complementary conduction drive circuit and are enabled to form an RC integrating circuit with corresponding resistors; and by adjusting the value of the time constant of the RC integrating circuit, practical on-time of the field effect transistors are controlled, and an object of changing dead-time is achieved. The drive circuit is simple in structure and reasonable in design, achieves complementary drive of the field effect transistors, has stable drive waveforms, and is a high-performance isolated drive circuit.

Description

A kind of switch power source driving circuit

Technical field

The utility model relates to a kind of switch power source driving circuit and Dead Time control method thereof, the drive circuit using in the complementary turning circuit of especially a kind of bridge-type.

Background technology

In the middle of Switching Power Supply, drive circuit is a very important part, and the power-supply system of high power density requires drive circuit simple, stable and efficient.At present, the drive circuit using in the complementary turning circuit of bridge-type has a variety of, totally can be divided into isolated form and non-isolation type, non-isolation type is mainly used in the middle of low-power circuit that insulation request is not high, and in driving in powerful circuit generally adopt isolated form.

Existing typical isolated form circuit as shown in Figure 1, in this circuit, electric capacity, for filtering flip-flop, drives and prevents that driving pulse from producing vibration for accelerating, for the gate charge of the field effect transistor of releasing fast, accelerate the cut-off of field effect transistor, resistance is for suppressing the spike of driving pulse; Although this circuit has been realized electrical isolation function, driver output is stable, but the bad adjusting of Dead Time between upper and lower field effect transistor, Dead Time is too short easily causes Q1 and Q3 conducting simultaneously to cause the accidents such as aircraft bombing, and Dead Time is oversize can cause again Q1 and the Q3 operating time is short, efficiency is low.

Utility model content

The purpose of this utility model, is to provide a kind of problem existing for foregoing circuit, the drive circuit of a kind of modified model adjustable deadband time of design.

To achieve these goals, the technical scheme that the utility model adopts is as follows:

A kind of switch power source driving circuit, comprise first input end, the second input, transformer, the first electric capacity, first ~ nine resistance, the first ~ six diode, the first triode, the second triode, the first field effect transistor, the second field effect transistor, positive output end and negative output terminal, described transformer comprises a former limit and two secondary, and two secondary have a shared output; First input end connects the one end on former limit through the first electric capacity, the second input connects the other end on former limit through the 9th resistance; Another output of the first secondary connects the anode of the first diode, the second resistance and the 3rd diodes in parallel, the 4th resistance and the second diodes in parallel, the negative electrode of the first diode connects respectively emitter, the negative electrode of the 3rd diode and the negative electrode of the second diode of the first triode through the first resistance, the grid of anodic bonding first field effect transistor of the second diode, the drain electrode of the first field effect transistor connects positive output end, and the anode of the first diode connects the base stage of the first triode through the 3rd resistance; Another output of the second secondary connects the anode of the 6th diode, the 6th resistance and the 5th diodes in parallel, the 8th resistance and the 4th diodes in parallel, the negative electrode of the 6th diode connects respectively emitter, the negative electrode of the 5th diode and the negative electrode of the 4th diode of the second triode through the 5th resistance, the grid of anodic bonding second field effect transistor of the 4th diode, the source electrode of the second field effect transistor connects negative output terminal, and the anode of the 6th diode connects the base stage of the second triode through the 7th resistance; Two shared outputs of secondary connect the collector electrode, the 3rd and anode, the source electrode of the first field effect transistor and the drain electrode of the second field effect transistor of the 5th diode of the first and second triodes, this circuit also comprises the second electric capacity and the 3rd electric capacity, and the emitter of described the first triode is connected the emitter of the second triode through the second electric capacity and the 3rd electric capacity.

Preferably, described the second electric capacity and the 3rd electric capacity are variable capacitance.

Preferably, described the first resistance and the 5th resistance are variable resistor.

Adopt after such scheme, a kind of switch power source driving circuit of the present utility model, by adding two electric capacity, makes two electric capacity form RC integrating circuit with corresponding resistance, by regulating the size of time constant of RC integrating circuit, realize the object that changes Dead Time; Not only simple in structure, reasonable in design, and realized preferably the complementary drive of field effect transistor, its drive waveforms has good stability, is a kind of high performance isolated drive circuit.

Brief description of the drawings

Fig. 1 is the circuit diagram of existing isolated form drive circuit.

Fig. 2 is the circuit diagram of a kind of switch power source driving circuit of the present utility model.

Fig. 3 is that R1, R5 get 200 Ω, and C2, C3 get the SIMETRIX simulation waveform of 5nF.

Fig. 4 is that R1, R5 get 200 Ω, and C2, C3 get the SIMETRIX simulation waveform of 10nF.

Fig. 5 is that R1, R5 get 100 Ω, and C2, C3 get the SIMETRIX simulation waveform of 5nF.

Wherein: C1 is that capacitance, C2, C3 are two electric capacity, T1 is transformer, D1, D2, D3, D4, D5, D6 are six diodes, Q2, Q4 are two triodes, Q1, Q3 are two field effect transistor, R1, R2, R3, R4, R5, R6, R7, R8, R9 are nine resistance, and HV+ is positive output end, and HV-is negative output terminal.

Embodiment

Below in conjunction with accompanying drawing, the technical solution of the utility model is described in further detail.

As shown in Figure 2, a kind of switch power source driving circuit, comprise first input end, the second input, transformer T1, the first capacitor C 1, the first ~ nine resistance (R1, R2, R3, R4, R5, R6, R7, R8, R9), the first ~ six diode (D1, D2, D3, D4, D5, D6), the first triode Q2, the second triode Q4, the first field effect transistor Q1, the second field effect transistor Q3, positive output end HV+ and negative output terminal HV-, transformer T1 comprises a former limit and two secondary, and two secondary have a shared output 8; One end 5, the second inputs that first input end connects former limit through C1 connect the other end 1 on former limit through R9; Another output 10 of the first secondary connects the anode of D1, and R2 is in parallel with D3, and R4 is in parallel with D2, the negative electrode of D1 connects respectively emitter, the negative electrode of D3 and the negative electrode of D2 of Q2 through R1, the grid of the anodic bonding Q1 of D2, the drain electrode of Q1 connects positive output end, and the anode of D1 connects the base stage of Q2 through R3; Another output 6 of the second secondary connects the anode of D6, and R6 is in parallel with D5, and R8 is in parallel with D4, the negative electrode of D6 connects respectively emitter, the negative electrode of D5 and the negative electrode of D4 of Q4 through R5, the grid of the anodic bonding Q3 of D4, the source electrode of Q3 connects negative output terminal, and the anode of D6 connects the base stage of Q4 through R7; Two shared outputs 8 of secondary connect the collector electrode of Q2, the collector electrode of Q4, the anode of D3, anode, the source electrode of Q1 and the drain electrode of Q3 of D5, this circuit also comprises the second capacitor C 2 and the 3rd capacitor C 3, and the emitter of described Q2 is connected the emitter of Q4 with C3 through C2.

C1 is capacitance, R9 mainly plays filtering peak voltage, D1, D6 is positive clipping diode, R1, R5 is charging resistor, and R1 and C2, R5 and C3 form two RC integrating circuit, by regulating the time constant of two RC integrating circuit, can regulate upper and lower field effect transistor Q1, the service time of Q3, R3 and the driving resistance that is driving Q2, R7 is the driving resistance that drives Q4, can suppress vibration, also can Limited Current, Q2, the effect of Q4 is at Q1, the conducting of Q3 shutdown moment, accelerate the shutoff of Q1 and Q3, reduce turn-off power loss, R2, R6, D3, D5 is for suppressing the spike of driving pulse, R4 is the driving resistance that drives Q1, R8 is the driving resistance that drives Q3, can suppress vibration, also can Limited Current, D2 and D4 can accelerate to drive and prevent that driving pulse from producing vibration.

The principle that this circuit is realized is as follows: the recurrent pulse waveform of giving a Symmetrical of the former limit input of transformer T1, in the time of input positive pulse, the secondary conducting that transformer T1 is connected with diode D1 and the secondary cut-off that is connected with diode D6, positive pulse charges to capacitor C 2 by resistance R 1, the time constant of RC integrating circuit size determine the actual ON time of field effect transistor, shutdown moment triode Q2 conducting, field effect transistor Q1 turn-offs immediately; In the time of input negative pulse, the secondary conducting that transformer T1 is connected with diode D6 and the secondary cut-off that is connected with diode D1, negative pulse charges to capacitor C 3 by resistance R 5, the size of the time constant of RC integrating circuit determines the actual ON time of field effect transistor, shutdown moment triode Q4 conducting, field effect transistor Q3 turn-offs immediately.Two courses of work are identical.The actual ON time of Q1 and Q3 just can be controlled according to actual needs like this, thereby regulates Dead Time.

As shown in Figure 3, for R1, R5 get 200 Ω, C2, C3 get the SIMETRIX simulation waveform of 5nF, shown in Fig. 4, for R1, R5 get 200 Ω, C2, C3 get the SIMETRIX simulation waveform of 10nF, shown in Fig. 5, for R1, R5 get 100 Ω, C2, C3 get the SIMETRIX simulation waveform of 5nF, in three figure, transverse axis is time/microsecond, and the longitudinal axis is voltage/volt.Can it is evident that from Fig. 3, Fig. 4, when the constant capacitance of resistance get larger time drive the rate of climb slower, delayed the conducting of field effect transistor Q1 and Q3; Can find out from Fig. 3, Fig. 5, hour driving rate of climb of getting when the constant resistance of electric capacity is rapider, has accelerated the conducting of field effect transistor Q1 and Q3, thereby has realized the object that regulates Dead Time.

Above embodiment is only explanation technological thought of the present utility model; can not limit protection range of the present utility model with this; every technological thought according to the utility model proposes, any change of doing on technical scheme basis, within all falling into the utility model protection range.

Claims

1. a switch power source driving circuit, comprise first input end, the second input, transformer, the first electric capacity, first ~ nine resistance, the first ~ six diode, the first triode, the second triode, the first field effect transistor, the second field effect transistor, positive output end and negative output terminal, described transformer comprises a former limit and two secondary, and two secondary have a shared output; First input end connects the one end on former limit through the first electric capacity, the second input connects the other end on former limit through the 9th resistance; Another output of the first secondary connects the anode of the first diode, the second resistance and the 3rd diodes in parallel, the 4th resistance and the second diodes in parallel, the negative electrode of the first diode connects respectively emitter, the negative electrode of the 3rd diode and the negative electrode of the second diode of the first triode through the first resistance, the grid of anodic bonding first field effect transistor of the second diode, the drain electrode of the first field effect transistor connects positive output end, and the anode of the first diode connects the base stage of the first triode through the 3rd resistance; Another output of the second secondary connects the anode of the 6th diode, the 6th resistance and the 5th diodes in parallel, the 8th resistance and the 4th diodes in parallel, the negative electrode of the 6th diode connects respectively emitter, the negative electrode of the 5th diode and the negative electrode of the 4th diode of the second triode through the 5th resistance, the grid of anodic bonding second field effect transistor of the 4th diode, the source electrode of the second field effect transistor connects negative output terminal, and the anode of the 6th diode connects the base stage of the second triode through the 7th resistance; Two shared outputs of secondary connect the collector electrode, the 3rd and anode, the source electrode of the first field effect transistor and the drain electrode of the second field effect transistor of the 5th diode of the first and second triodes, it is characterized in that: also comprise the second electric capacity and the 3rd electric capacity, the emitter of described the first triode is connected the emitter of the second triode through the second electric capacity and the 3rd electric capacity.

2. switch power source driving circuit as claimed in claim 1, is characterized in that: described the second electric capacity and the 3rd electric capacity are variable capacitance.

3. switch power source driving circuit as claimed in claim 1, is characterized in that: described the first resistance and the 5th resistance are variable resistor.