CN216794850U

CN216794850U - Push-pull boost circuit module and push-pull boost circuit

Info

Publication number: CN216794850U
Application number: CN202220116267.7U
Authority: CN
Inventors: 杜燕清
Original assignee: Shenzhen Jiuding Technology Co ltd
Current assignee: Shenzhen Jiuding Technology Co ltd
Priority date: 2022-01-17
Filing date: 2022-01-17
Publication date: 2022-06-21
Anticipated expiration: 2032-01-17

Abstract

The utility model discloses a push-pull boost circuit module and a push-pull boost circuit, comprising a push-pull transformer Tx, a switching tube Q3 and a switching tube Q4; the second end and the third end of the push-pull transformer Tx are both connected with an external input power supply, the drain electrode of a switching tube Q3 and the drain electrode of a switching tube Q4 are respectively connected to the first end and the fourth end of a primary winding of the push-pull transformer Tx, the source electrode of a switching tube Q3 and the source electrode of a switching tube Q4 are both grounded, and the grid electrode of a switching tube Q3 and the grid electrode of a switching tube Q4 are respectively connected with an external driving circuit module; the capacitor C34 is connected between the grid electrode and the drain electrode of the switch tube Q3, the capacitor C35 is connected between the grid electrode and the drain electrode of the switch tube Q4, the Miller effect can be enhanced, the charging time can be prolonged, the loss time can be prolonged, and when the switch tube is turned off, most of the peak voltage generated by the Miller effect is consumed in the process of turning on the switch tube, so that the peak value of the reverse voltage cannot be too large.

Description

Push-pull boost circuit module and push-pull boost circuit

Technical Field

The utility model relates to the technical field of push-pull circuits, in particular to a push-pull boosted circuit module and a push-pull boosted circuit.

Background

In the push-pull boost circuit, when the switching tube is turned off, a reverse spike voltage is generated, the reverse spike voltage cannot be effectively inhibited in the conventional push-pull boost circuit, a high-power TVS (transient diode) is usually increased, or the switching speed of the switching tube is reduced to achieve the purpose of absorbing the reverse spike voltage, the circuit cost is high, and the system conversion efficiency is low.

SUMMERY OF THE UTILITY MODEL

In view of the above, it is desirable to provide a push-pull boost circuit module and a push-pull boost circuit, which can solve the problems that the conventional push-pull boost circuit cannot effectively suppress the reverse spike voltage, and has high circuit cost and low system conversion efficiency.

To achieve the above object, in a first aspect, the present invention provides a push-pull boost circuit module, including: a push-pull transformer Tx, a switching tube Q3 and a switching tube Q4;

the second end and the third end of the push-pull transformer Tx are both connected with an external input power supply, the drain electrode of the switching tube Q3 and the drain electrode of the switching tube Q4 are respectively connected to the first end and the fourth end of the primary winding of the push-pull transformer Tx, the source electrode of the switching tube Q3 and the source electrode of the switching tube Q4 are both grounded, and the grid electrode of the switching tube Q3 and the grid electrode of the switching tube Q4 are respectively connected with an external driving circuit module;

a capacitor C34 is connected between the gate and the drain of the switching tube Q3, a capacitor C35 is connected between the gate and the drain of the switching tube Q4, a capacitor C36 is connected between the drain and the source of the switching tube Q3, and a capacitor C37 is connected between the drain and the source of the switching tube Q4.

Further, the device also comprises a resistor R13, a diode D5, a resistor R24 and a diode D10, wherein the resistor R13 is connected in parallel with the diode D5, and the resistor R24 is connected in parallel with the diode D10; the anode of the diode D5 and the anode of the diode D10 are respectively connected to the gate of the switching tube Q3 and the gate of the switching tube Q4, and the cathode of the diode D5 and the cathode of the diode D10 are respectively externally connected to the driving circuit module.

Further, a leakage resistor R3 and a leakage resistor R18 are respectively disposed between the gate and the source of the switching tube Q3 and between the gate and the source of the switching tube Q4.

Further, a driving resistor R6 is connected between the gate of the switching tube Q3 and the diode D5, and a driving resistor R20 is connected between the gate of the switching tube Q4 and the diode D10.

In a second aspect, the present invention provides a push-pull boost circuit, including any one of the push-pull boost circuit modules in the first aspect.

Further, the device also comprises a control circuit module and a driving circuit module; the control circuit module is connected with the driving circuit module, and the driving circuit module is connected with the push-pull booster circuit module.

Furthermore, two sets of driving circuit modules are provided, and are respectively used for driving the switching tube Q3 and the switching tube Q4 in the push-pull boost circuit module.

Further, the driving circuit module comprises an NPN type triode, a PNP type triode and a field effect transistor;

the grid electrode of the field effect tube is connected with the control circuit module, the drain electrode of the field effect tube is respectively connected with the base electrode of the NPN type triode and the base electrode of the PNP type triode, and the source electrode of the field effect tube is grounded; the emitting electrode of the NPN type triode is connected with the emitting electrode of the PNP type triode, the collecting electrode of the NPN type triode is connected with an external power supply, and the collecting electrode of the PNP type triode is grounded.

Further, the control circuit module includes a CSU32P10 chip.

Through the technical scheme, the utility model at least has the following beneficial effects:

1. after the switching tube is conducted, Vds of the switching tube begins to fall, Id begins to rise, the switching tube enters a saturation region at the moment, however, due to the effect of tube junction capacitance, a Miller effect can be generated, Vgs can not rise for a period of time, Id reaches the maximum at the moment, Vds continues to fall until Miller capacitance (Crss) is fully charged, Vgs rises to the value of driving voltage again, the switching tube enters a resistance region at the moment, and Vds completely falls at the moment. The capacitor C34 and the capacitor C35 are respectively connected between the grid electrode and the drain electrode of the switching tube Q3 and the switching tube Q4, so that the Miller effect can be enhanced, the charging time can be prolonged, and the loss time can be prolonged. The capacitor C36 and the capacitor C37 are connected between the drain and the source of the switching tube Q3 and the switching tube Q4, so that the oscillation of the switching tube Vds in the miller effect can be reduced.

2. The problem of reverse peak voltage can be solved only by a simple capacitor element, EMC testing can be facilitated, production cost is hardly increased on an original circuit, and the problem of low system conversion efficiency caused by the fact that other modes are adopted to absorb the reverse peak voltage is avoided;

3. meanwhile, on the aspect of considering the selection of the switching tubes Cgd and Cds, the matching selection difficulty is reduced, and more switching tubes with different specifications can be matched by adjusting the sizes of the capacitor C34, the capacitor C35, the capacitor C36 and the capacitor C37.

Drawings

100. A push-pull boost circuit module; 200. a control circuit module; 300. and a driving circuit module.

Fig. 1 is a schematic diagram of a push-pull boost circuit module according to a first embodiment of the present invention;

FIG. 2 is a schematic diagram of a control circuit module according to a second embodiment of the present invention;

FIG. 3 is a schematic diagram of a driving circuit module according to a second embodiment of the present invention;

fig. 4 is a schematic block diagram of a second embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly apparent, a push-pull boost circuit module and a push-pull boost circuit according to the present invention are described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the utility model and are not intended to limit the utility model.

Example one

It is understood that the miller effect refers to an effect that the distributed capacitance Cgd between the input and the output is amplified by the inverse amplification, so that the miller effect forms a miller platform. When Cgs reaches a threshold voltage, a MOSFET (metal oxide semiconductor field effect transistor) enters an on state; after the MOSFET is switched on, Vds begins to fall, Id begins to rise, and the MOSFET enters a saturation region; but due to the miller effect Vgs will not rise any longer for a period of time, at which time Id has reached a maximum, and Vds will continue to fall until the miller capacitance (Cgd) is fully charged, Vgs rises again to the value of the drive voltage, at which time the MOSFET enters the resistive region, Vds falls completely, and turn-on ends.

Referring to fig. 1, the present invention provides a push-pull boost circuit module, including: a push-pull transformer Tx, a switching tube Q3 and a switching tube Q4; the second end and the third end of the push-pull transformer Tx are both connected with an external input power supply, the drain electrode of the switching tube Q3 and the drain electrode of the switching tube Q4 are respectively connected to the first end and the fourth end of the primary winding of the push-pull transformer Tx, the source electrode of the switching tube Q3 and the source electrode of the switching tube Q4 are both grounded, and the grid electrode of the switching tube Q3 and the grid electrode of the switching tube Q4 are respectively connected with an external driving circuit module; a capacitor C34 is connected between the gate and the drain of the switching tube Q3, a capacitor C35 is connected between the gate and the drain of the switching tube Q4, a capacitor C36 is connected between the drain and the source of the switching tube Q3, and a capacitor C37 is connected between the drain and the source of the switching tube Q4. According to the charge pump, the capacitor C34 and the capacitor C35 are respectively connected between the grid electrode and the drain electrode of the switching tube Q3 and the switching tube Q4, so that the Mailer effect can be enhanced, the charging time is prolonged, and the loss time is prolonged. The capacitor C36 and the capacitor C37 are connected between the drain and the source of the switching tube Q3 and the switching tube Q4, so that the oscillation of the switching tube Vds in the miller effect can be reduced.

In this embodiment, the device further includes a resistor R13, a diode D5, a resistor R24, and a diode D10, wherein the resistor R13 is connected in parallel with the diode D5, and the resistor R24 is connected in parallel with the diode D10; the anode of the diode D5 and the anode of the diode D10 are respectively connected to the gate of the switching tube Q3 and the gate of the switching tube Q4, and the cathode of the diode D5 and the cathode of the diode D10 are respectively externally connected to the driving circuit module. As shown in the figure. When the OUTA or OUTB network terminal receives a high-level signal, the diode D5 and the diode 10 are not functioning, and the resistor R20 or the resistor R13 may increase the circuit impedance, so as to prevent the switching tube Q3 and the switching tube Q4 from breaking down due to an excessive voltage. When the OUTA or OUTB network terminal receives a low level signal, the diode D5 and the diode D10 short-circuit the resistor R20 or the resistor R13, respectively, so that the switch Q3 or the switch Q4 can be turned off quickly.

In this embodiment, the drain resistors R3 and R18 are respectively disposed between the gate and the source of the switching tube Q3 and between the gate and the source of the switching tube Q4, so as to provide bias voltages for the switching tube Q3 and the switching tube Q4, and since the resistance value between the G-S poles of the switching tube is very large, a very high voltage can be generated across the equivalent capacitor between the G-S poles as long as a small amount of static electricity exists, and if the small amount of static electricity is not discharged in time, the field effect transistor may malfunction, and even may break down the G-S poles. The leakage resistor R3 and the leakage resistor R18 can discharge the static electricity, thereby protecting the switching tube Q3 and the switching tube Q4.

In this embodiment, a driving resistor R6 is connected between the gate of the switching tube Q3 and the diode D5, and a driving resistor R20 is connected between the gate of the switching tube Q4 and the diode D10, so that the steepness of the front and rear edges of the gate input control pulse of the switching tube Q3 or the switching tube Q4 can be changed, the oscillation formed by the parasitic capacitance and the inductance can be prevented, the peak of the output voltage can be reduced, and the switching tube Q3 and the switching tube Q4 can be prevented from being burnt out.

Example two

Referring to fig. 1-4, the present invention provides a push-pull boost circuit, including any one of the push-pull boost circuit modules 100 of the first aspect. In this embodiment, the device further includes a control circuit module 200 and a driving circuit module 300; the control circuit module 200 is connected to the driving circuit module 300, and the driving circuit module 300 is connected to the push-pull boost circuit module 100. The control circuit module 200 controls the driving circuit module 300 to make the driving circuit module 300 drive the push-pull boosting circuit module 100. The driving circuit module 300 has two sets, which are respectively used for driving the switching tube Q3 and the switching tube Q4 in the push-pull boost circuit module 100.

Specifically, the driving circuit module 300 includes an NPN transistor (i.e., shown as Q10 or Q11), a PNP transistor (i.e., shown as Q12 or Q13), and a field effect transistor (i.e., shown as Q14 or Q15); the grid electrode of the field effect transistor is connected with the control circuit module 200, the drain electrode of the field effect transistor is respectively connected with the base electrode of the NPN type triode and the base electrode of the PNP type triode, and the source electrode of the field effect transistor is grounded; the emitting electrode of the NPN type triode is connected with the emitting electrode of the PNP type triode, the collecting electrode of the NPN type triode is connected with an external power supply, and the collecting electrode of the PNP type triode is grounded.

During the circuit operation, the duty ratio of the control circuit module 200 controls the two sets of driving circuit modules 300 to alternately drive the switching tube Q3 and the switching tube Q4. If the field effect transistor of the first group of driving circuit modules is given a high level by the control circuit module, the field effect transistor is conducted, further the PNP type triode is conducted, the NPN type triode is cut off, at this time, the field effect transistor of the second group of driving circuit modules is given a low level by the control circuit module, the field effect transistor is cut off, the NPN type triode is conducted, further the PNP type triode is cut off, namely, the first group of driving circuit modules OUTA outputs a low level, the second group of driving circuit modules OUTB outputs a high level, at this time, the switch tube Q3 is turned off, and the switch tube Q4 is conducted. When the fets in the first group of driving circuit modules are given a low level by the control circuit module, the fets in the second group of driving circuit modules are given a high level by the control circuit module 200, and at this time, the switch Q3 is turned on, and the switch Q4 is turned off, which has the same principle as described above.

Preferably, the control circuit module 200 includes a CSU32P10 chip, and the CSU32P10 chip is an 8-bit RISC MCU and a high-performance single-chip with 12-bit ADC. A 2K × 14 bit OTP program memory is built in.

The utility model is not described in detail, but is well known to those skilled in the art.

It will be evident to those skilled in the art that the utility model is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the utility model being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Claims

1. A push-pull boost circuit module, comprising: a push-pull transformer Tx, a switching tube Q3 and a switching tube Q4;

a capacitor C34 is connected between the grid and the drain of the switching tube Q3, a capacitor C35 is connected between the grid and the drain of the switching tube Q4, a capacitor C36 is connected between the drain and the source of the switching tube Q3, and a capacitor C37 is connected between the drain and the source of the switching tube Q4.

2. The push-pull boost circuit module according to claim 1, further comprising a resistor R13, a diode D5, a resistor R24, and a diode D10, wherein the resistor R13 is connected in parallel with the diode D5, and the resistor R24 is connected in parallel with the diode D10;

the anode of the diode D5 and the anode of the diode D10 are respectively connected to the gate of the switching tube Q3 and the gate of the switching tube Q4, and the cathode of the diode D5 and the cathode of the diode D10 are respectively externally connected to the driving circuit module.

3. The push-pull boost circuit module according to claim 1, wherein a leakage resistor R3 and a leakage resistor R18 are respectively disposed between the gate and the source of the switching transistor Q3 and between the gate and the source of the switching transistor Q4.

4. The push-pull boost circuit module according to claim 2, characterized in that a driving resistor R6 is connected between the gate of the switching transistor Q3 and the diode D5, and a driving resistor R20 is connected between the gate of the switching transistor Q4 and the diode D10.

5. Push-pull boost circuit, characterized in that it comprises a push-pull boost circuit module (100) according to any of the previous claims 1-4.

6. The push-pull boost circuit according to claim 5, further comprising a control circuit module (200) and a driving circuit module (300);

the control circuit module (200) is connected with the driving circuit module (300), and the driving circuit module (300) is connected with the push-pull boosting circuit module (100).

7. The push-pull boost circuit according to claim 6, wherein the driving circuit module (300) has two sets for driving the switch Q3 and the switch Q4 of the push-pull boost circuit module (100), respectively.

8. The push-pull boost circuit according to claim 7, wherein the driving circuit module (300) comprises an NPN transistor, a PNP transistor, and a field effect transistor;

the grid electrode of the field effect tube is connected with the control circuit module (200), the drain electrode of the field effect tube is respectively connected with the base electrode of the NPN type triode and the base electrode of the PNP type triode, and the source electrode of the field effect tube is grounded;

and the emitter of the NPN type triode is connected with the emitter of the PNP type triode, the collector of the NPN type triode is connected with an external power supply, and the collector of the PNP type triode is grounded.

9. Push-pull boost circuit according to claim 6, characterized in that the control circuit block (200) comprises a CSU32P10 chip.