阅读说明：本技术 一种新型mosfet驱动电路 (Novel MOSFET drive circuit ) 是由 蒋东方 于 2020-05-14 设计创作，主要内容包括：本发明属于汽车充电机领域,具体公开了一种新型MOSFET驱动电路,包括驱动变压器T1、二极管D21,D22,D23,D24、三极管Q2,Q3,Q4,Q5以及稳压二极管D42,D44,D46,D47；驱动变压器T1的次级10脚连接电阻R50的第一端,驱动变压器T1的次级6脚连接二极管D23的3-3脚；电阻R50的第二端连接二极管D22的负极,二极管D22的正极连接驱动变压器T1的次级9脚。本发明的驱动电路具有驱动电压转换快,关断损耗小的优点,同时降低了成产成本,以及故障发生率,从驱动变压器过来的正脉冲带有很多尖刺,通过二极管D21的1脚处的电容C78和电阻R55、R70构成的电路可以吸收那些尖刺,让到达DRVH处的脉冲波形更加纯净。(The invention belongs to the field of automobile chargers, and particularly discloses a novel MOSFET (metal oxide semiconductor field effect transistor) driving circuit which comprises a driving transformer T1, diodes D21, D22, D23, D24, triodes Q2, Q3, Q4, Q5, voltage-stabilizing diodes D42, D44, D46 and D47; the secondary 10 pin of the driving transformer T1 is connected with the first end of the resistor R50, and the secondary 6 pin of the driving transformer T1 is connected with the 3-3 pins of the diode D23; the second end of the resistor R50 is connected to the cathode of the diode D22, and the anode of the diode D22 is connected to the secondary 9-pin of the driving transformer T1. The driving circuit has the advantages of fast driving voltage conversion and small turn-off loss, simultaneously reduces the production cost and the failure occurrence rate, positive pulses from the driving transformer have a plurality of spikes, and the circuit formed by the capacitor C78 at the 1 pin of the diode D21 and the resistors R55 and R70 can absorb the spikes, so that the pulse waveform reaching the DRVH part is cleaner.)

1. A novel MOSFET driving circuit is characterized by comprising a driving transformer T1, diodes D21, D22, D23, D24, a triode Q2, Q3, Q4, Q5, voltage stabilizing diodes D42, D44, D46 and D47, wherein a pin 10 of the secondary side of the driving transformer T1 is connected with a first end of a resistor R50, and a pin 6 of the secondary side of the driving transformer T1 is connected with pins 3-3 of a diode D23; the second end of the resistor R50 is connected with the cathode of a diode D22, and the anode of a diode D22 is connected with the secondary 9 pin of the driving transformer T1; the base of the triode Q3 is connected with the second end of the resistor R50, the emitter of the triode Q3 is connected with the second end of the resistor R60, the first end of the resistor R60 is connected with the second end of the resistor R69, and the first end of the resistor R69 is connected with the pin 3-2 of the diode D21; the pin 3-3 of the diode D21 is connected with the first end of the resistor R50, the pin 3-1 of the diode D21 is connected with the first end of the resistor R55, and the second end of the resistor R55 is connected with the anode of the diode D22; the second end of the resistor R70 is connected to the second end of the resistor R55, the first end of the resistor R70 is connected to the second end of the capacitor C78, and the first end of the capacitor C78 is connected to the first end of the resistor R55.

2. The novel MOSFET driver circuit of claim 1, wherein: the base electrode of the triode Q3 is connected with the negative electrode of the diode D22, the collector electrode of the triode Q2 is connected with the collector electrode of the triode Q3, the base electrode of the triode Q2 is connected with the second end of the resistor R60, and the emitter electrode of the triode Q2 is connected with the first end of the resistor R60.

3. The novel MOSFET driver circuit of claim 1, wherein: the cathode of the zener diode D42 is connected with the emitter of the triode Q2, the anode of the zener diode D42 is connected with the second end of the capacitor C53, and the first end of the capacitor C53 is connected with the collector of the triode Q2; the anode of the zener diode D44 is connected to the first end of the capacitor C53, and the cathode of the zener diode D44 is connected to the second end of the capacitor C53.

4. The novel MOSFET driver circuit of claim 1, wherein: a pin 3-2 of the diode D23 is connected with a first end of the resistor R65, a pin 3-1 of the diode D23 is connected with a first end of the resistor R46, second ends of the resistor R65 and the resistor R46 are respectively connected with a first end of the resistor R68 and an anode of the diode D24, a pin 7 of a secondary pole of the driving transformer T1 is connected with an anode of the diode D24, a cathode of the diode D24 is connected with a second end of the resistor R66, and a first end of the resistor R66 is connected with a pin 3-3 of the diode D23; the first end of the resistor R68 is connected with the emitter of the triode Q4, the base of the triode Q4 is connected with the cathode of the diode D24, and the collector of the triode Q4 is connected with the second end of the resistor R45; the first end of the resistor R45 is connected with the second end of the capacitor C79, the second end of the resistor R45 is connected with the second end of the resistor R46, and the first end of the capacitor C79 is connected with the first end of the resistor R46.

5. The novel MOSFET driver circuit of claim 4, wherein: the emitter of the triode Q4 is connected with the first end of the resistor R68, the base of the triode Q4 is connected with the emitter of the transistor Q5, and the collector of the triode Q4 is connected with the collector of the triode Q4.

6. The novel MOSFET driver circuit of claim 1, wherein: the cathode of the zener diode D47 is connected with the emitter of the triode Q4, the anode of the zener diode D47 is connected with the second end of the capacitor C54, the first end of the capacitor C54 is connected with the collector of the triode Q4, the first end of the zener diode D46 is connected with the first end of the capacitor C54, and the second end of the zener diode D46 is connected with the second end of the capacitor C54 and grounded.

Technical Field

The invention relates to the field of automobile chargers, in particular to a novel MOSFET (metal-oxide-semiconductor field effect transistor) driving circuit.

Background

In recent years, environmental pollution is serious, environmental protection and energy conservation become popular topics, and the rising of some new energy industries including new energy electric automobiles is promoted. The reliability is one of important indexes for measuring the performance of the charger, and in the charger, an LLC driving circuit is a vital part, and the working state of the LLC driving circuit can directly influence the normal output of the whole charger. Efficient and low cost solutions for LLC driver circuits are therefore sought. At present, half-bridge LLC resonance or full-bridge converters are widely applied, and driving circuits of the half-bridge LLC resonance or full-bridge converters are various, but most of the driving circuits are difficult in type selection, high in cost, slow in driving turn-off, large in turn-off loss and low in efficiency. In order to solve the technical problems, the invention provides a driving circuit with fast driving voltage conversion and small turn-off loss.

Disclosure of Invention

The present invention is directed to a novel MOSFET driving circuit to solve the above-mentioned problems.

In order to achieve the purpose, the invention provides the following technical scheme: a novel MOSFET driving circuit comprises a driving transformer T1, diodes D21, D22, D23, D24, a triode Q2, Q3, Q4, Q5, voltage stabilizing diodes D42, D44, D46 and D47, wherein a secondary 10 pin of the driving transformer T1 is connected with a first end of a resistor R50, and a secondary 6 pin of the driving transformer T1 is connected with pins 3-3 of a diode D23; the second end of the resistor R50 is connected with the cathode of a diode D22, and the anode of a diode D22 is connected with the secondary 9 pin of the driving transformer T1; the base of the triode Q3 is connected with the second end of the resistor R50, the emitter of the triode Q3 is connected with the second end of the resistor R60, the first end of the resistor R60 is connected with the second end of the resistor R69, and the first end of the resistor R69 is connected with the pin 3-2 of the diode D21; the pin 3-3 of the diode D21 is connected with the first end of the resistor R50, the pin 3-1 of the diode D21 is connected with the first end of the resistor R55, and the second end of the resistor R55 is connected with the anode of the diode D22; the second end of the resistor R70 is connected to the second end of the resistor R55, the first end of the resistor R70 is connected to the second end of the capacitor C78, and the first end of the capacitor C78 is connected to the first end of the resistor R55.

Preferably, the base of the transistor Q3 is connected to the cathode of the diode D22, the collector of the transistor Q2 is connected to the collector of the transistor Q3, the base of the transistor Q2 is connected to the second terminal of the resistor R60, and the emitter of the transistor Q2 is connected to the first terminal of the resistor R60.

Preferably, the cathode of the zener diode D42 is connected to the emitter of the transistor Q2, the anode of the zener diode D42 is connected to the second end of the capacitor C53, and the first end of the capacitor C53 is connected to the collector of the transistor Q2; the anode of the zener diode D44 is connected to the first end of the capacitor C53, and the cathode of the zener diode D44 is connected to the second end of the capacitor C53.

Preferably, a pin 3-2 of the diode D23 is connected to a first end of the resistor R65, a pin 3-1 of the diode D23 is connected to a first end of the resistor R46, second ends of the resistor R65 and the resistor R46 are respectively connected to a first end of the resistor R68 and an anode of the diode D24, a pin 7 of the secondary winding of the driving transformer T1 is connected to an anode of the diode D24, a cathode of the diode D24 is connected to a second end of the resistor R66, and a first end of the resistor R66 is connected to a pin 3-3 of the diode D23; the first end of the resistor R68 is connected with the emitter of the triode Q4, the base of the triode Q4 is connected with the cathode of the diode D24, and the collector of the triode Q4 is connected with the second end of the resistor R45; the first end of the resistor R45 is connected with the second end of the capacitor C79, the second end of the resistor R45 is connected with the second end of the resistor R46, and the first end of the capacitor C79 is connected with the first end of the resistor R46.

Preferably, an emitter of the transistor Q4 is connected to the first end of the resistor R68, a base of the transistor Q4 is connected to an emitter of the transistor Q5, and a collector of the transistor Q4 is connected to a collector of the transistor Q4.

Preferably, the cathode of the zener diode D47 is connected to the emitter of the transistor Q4, the anode of the zener diode D47 is connected to the second terminal of the capacitor C54, the first terminal of the capacitor C54 is connected to the collector of the transistor Q4, the first terminal of the zener diode D46 is connected to the first terminal of the capacitor C54, and the second terminal of the zener diode D46 is connected to the second terminal of the capacitor C54 and grounded.

Compared with the prior art, the invention has the beneficial effects that:

the driving circuit has the advantages of fast driving voltage conversion and small turn-off loss, simultaneously reduces the production cost and the failure occurrence rate, positive pulses from the driving transformer are provided with a plurality of sharp spines, and the circuit formed by the capacitor C78 at the 1 pin of the diode D21 and the resistors R55 and R70 can absorb the sharp spines, so that the pulse waveform reaching the G pole of the DRVH (driving MOS transistor) is purer, the power consumption is reduced, and the reliability is improved.

Drawings

FIG. 1 is a driving circuit diagram of the present invention;

FIG. 2 is a circuit diagram of a driving MOS transistor according to an embodiment of the invention;

FIG. 3 is a drawing of an embodiment of the present invention;

fig. 4 is a circuit diagram of a driver chip according to an embodiment of the invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1, the present invention provides a technical solution: a novel MOSFET driving circuit comprises a driving transformer T1, diodes D21, D22, D23, D24, a triode Q2, Q3, Q4, Q5, voltage stabilizing diodes D42, D44, D46 and D47, wherein a secondary 10 pin of the driving transformer T1 is connected with a first end of a resistor R50, and a secondary 6 pin of the driving transformer T1 is connected with pins 3-3 of a diode D23; the second end of the resistor R50 is connected with the cathode of a diode D22, and the anode of a diode D22 is connected with the secondary 9 pin of the driving transformer T1; the base of the triode Q3 is connected with the second end of the resistor R50, the emitter of the triode Q3 is connected with the second end of the resistor R60, the first end of the resistor R60 is connected with the second end of the resistor R69, and the first end of the resistor R69 is connected with the pin 3-2 of the diode D21; the pin 3-3 of the diode D21 is connected with the first end of the resistor R50, the pin 3-1 of the diode D21 is connected with the first end of the resistor R55, and the second end of the resistor R55 is connected with the anode of the diode D22; the second end of the resistor R70 is connected to the second end of the resistor R55, the first end of the resistor R70 is connected to the second end of the capacitor C78, and the first end of the capacitor C78 is connected to the first end of the resistor R55.

In this embodiment, the base of the transistor Q3 is connected to the cathode of the diode D22, the collector of the transistor Q2 is connected to the collector of the transistor Q3, the base of the transistor Q2 is connected to the second terminal of the resistor R60, and the emitter of the transistor Q2 is connected to the first terminal of the resistor R60.

In this embodiment, the cathode of the zener diode D42 is connected to the emitter of the transistor Q2, the anode of the zener diode D42 is connected to the second terminal of the capacitor C53, and the first terminal of the capacitor C53 is connected to the collector of the transistor Q2; the anode of the zener diode D44 is connected to the first end of the capacitor C53, and the cathode of the zener diode D44 is connected to the second end of the capacitor C53.

In this embodiment, pin 3-2 of diode D23 is connected to the first end of resistor R65, pin 3-1 of diode D23 is connected to the first end of resistor R46, the second ends of resistor R65 and resistor R46 are connected to the first end of resistor R68 and the anode of diode D24, respectively, pin 7 of the secondary winding of driving transformer T1 is connected to the anode of diode D24, the cathode of D24 is connected to the second end of resistor R66, and the first end of resistor R66 is connected to pin 3-3 of diode D23; the first end of the resistor R68 is connected with the emitter of the triode Q4, the base of the triode Q4 is connected with the cathode of the diode D24, and the collector of the triode Q4 is connected with the second end of the resistor R45; the first end of the resistor R45 is connected with the second end of the capacitor C79, the second end of the resistor R45 is connected with the second end of the resistor R46, and the first end of the capacitor C79 is connected with the first end of the resistor R46.

In this embodiment, the emitter of the transistor Q4 is connected to the first end of the resistor R68, the base of the transistor Q4 is connected to the emitter of the transistor Q5, and the collector of the transistor Q4 is connected to the collector of the transistor Q4.

In this embodiment, the cathode of the zener diode D47 is connected to the emitter of the transistor Q4, the anode of the zener diode D47 is connected to the second terminal of the capacitor C54, the first terminal of the capacitor C54 is connected to the collector of the transistor Q4, the first terminal of the zener diode D46 is connected to the first terminal of the capacitor C54, and the second terminal of the zener diode D46 is connected to the second terminal of the capacitor C54 and grounded.

The pulse signal of the invention has positive and negative two types. That is, when the pulse is positive, the high level of the positive pulse of the driving transformer T1 passes through the pin 3-2 of the diode D21, passes through the resistor R69, and reaches the driving MOS transistor.

Referring to fig. 1-2, fig. 2 shows a driving MOS transistor circuit of the present invention, the driving MOS transistor circuit is composed of a first secondary side T1A of a driving transformer T1, N-channel fets Q5 and Q6, capacitors C7 and C8, and diodes D7 and D8, the driving voltage of the fet Q5 as an upper tube is opposite to the driving voltage of the fet Q6 as a lower tube, and a dead zone exists between the Q5 and the Q6, so as to prevent the Q5 and the Q6 from being turned on simultaneously to cause damage, and ensure a correct timing, i.e., the dead zone exists, as shown in fig. 3.

In this embodiment, the driving circuit in fig. 1 has two kinds of positive and negative pulse signals, that is, when the pulse is positive, the level of the secondary 10 pin of the driving transformer T1 is higher than 9 pins, the high level of the positive pulse passes through the 3-2 pin of the diode D21 and the resistor R69, and then reaches the gate (DRV-a) of the driving MOS transistor Q5 in fig. 2, the positive pulse from the driving transformer has many spikes, the circuit formed by the capacitor C78 at the 1 pin of the diode D21 and the resistors R55 and R70 can absorb the spikes, so that the pulse waveform reaching the G pole (DRVH) of the driving MOS transistor is cleaner;

when the pulse is negative, the level of the secondary pin 10 of the driving transformer T1 is lower than that of the secondary pin 9, the base electrodes of the triodes Q2 and Q3 are low, at this time, the electricity at the DRVH (driving MOS tube G pole) can be quickly discharged through the triodes Q2 and Q3, the capacitor C53 and the zener diode D44 at the HS make a negative bias to quickly turn off the pulse, and the positive and negative pulse signals have two.

Referring to fig. 4, fig. 4 shows a driver chip circuit of the present invention, which is composed of a chip U5, resistors R16, R26, R75, R76 and capacitors C28 and C77, wherein the R76 and the capacitor C77 in the driver chip circuit are respectively connected to the primary 2 pin and the 4 pin of the driving transformer T1.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.