CN1087884C

CN1087884C - Simple high-efficiency separated insulated-gate high-power component driving circuit

Info

Publication number: CN1087884C
Application number: CN95101392A
Authority: CN
Inventors: 陈亚宁; 魏顺长
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-02-15
Filing date: 1995-02-15
Publication date: 2002-07-17
Anticipated expiration: 2015-02-15
Also published as: CN1129373A

Abstract

The present invention provides an insulated-gate high-power device drive circuit which is isolated by a drive transformer. The driving circuit with no need of matching any external power supply unit can output drive pulses with steep front edges and steep back edges to drive a single tube circuit, a half-bridge or a full-bridge circuit, and simultaneously, the driving circuit has short responsible time.

Description

The driver for isolating of insulated gate device

The invention belongs to field of power supplies, relate to the power tube Driving technique in the Switching Power Supply.

The design one of power device drive circuit (driver) is to being one of key technology of field of power supplies in the Switching Power Supply.VMOS field effect transistor devices such as (and) IGBT insulated gate bipolar high power valves has the grid structure of insulation, thereby the static drive power interface is bordering on zero.But because they have bigger grid capacitance Cgs and because Miller effect is amplified the capacitance of drain Cdg be transformed into grid, thereby need bigger dynamic driving power.

Be the reliable insulated gate device that drives, at present existing a lot of ripe circuit, abroad introduced as file AN-937, the AN-978A of U.S.'s international rectifier (IR) company, domestic as 93 year November the tenth power supply association collection of thesis introduce, and the article of other many magazines is disclosed.

When modulation signal and power device did not need to isolate, the design of driver was fairly simple, at present some outstanding drive integrated circults has been arranged also, as IR2110.When the needs electrical isolation, two kinds of methods are arranged generally: adopt photoelectrical coupler, or utilize the pulsed drive transformer that electrical isolation is provided.

The shortcoming of first method: the reaction of A. photoelectrical coupler is slower, thereby has bigger time of delay (the high-speed type optocoupler is generally also greater than 1000ns), although existing now ultrahigh speed optocoupler, not only price is more expensive, and speed is still not as good as circuit of the present invention; B. the output stage of the photoelectrical coupler accessory power supply power supply that also needs to isolate.

The ball bearing made using of second method is to be example with the half-bridge circuit as shown in Figure 1 here.This method is very simple, does not also need independent driving power, but shortcoming is to drive the very little low-power device of grid source capacitor C gs.If insulated gate device T4, T5 are high power device, so capacitor C gs is bigger in its grid source, cause the serious distortion of waveform Vgs between the grid source electrode, unless change elementary input signal into certain power large-signal, respective drive transformer B1 also should get larger volume.

At present in order to drive high power device, all be to insert amplifying unit between the secondary and power tube, and provide power supply in addition to it at driving transformer with isolating transformer.Chinese patent CN1070069A " a kind of power VMOS tube double isolation driving circuit " has announced a kind of new effective ways, and principle as shown in Figure 2.Wherein unit 5 is for there being the buffer circuit of four pipes; Unit 6 is for there being the drive part of three pipes and a comparator, and this part has independent accessory power supply in addition.This patent has solved isolation and speed issue, but circuit is complicated and need other stand-by power source.

The purpose of this invention is to provide a kind of transformer isolation formula insulated-gate power device driver that does not need accessory power supply and export to have to hang down delay and precipitous triggering along driving pulse.

Technical scheme of the present invention is: coupling pulse transformer (1) and amplifying unit (3) are arranged in the part of driver, and wherein transformer (1) is made of miniature ferrite pulse transformer, and elementary is input of the present invention, receives in the output of prime; Secondary lower end is common port COM, and the upper end is output Vt.Amplifying unit (3) can be any active plug-type amplifying circuit, and it has signal input part Si and output end vo, and common port COM and power end Vcc are also arranged certainly.The effect of transformer (1) is an electrical isolation, and the effect of amplifying unit (3) is that the pulse-modulated signal that transformer (1) transmits is amplified to drive insulated-gate power device (4).Transformer (1) secondary output end Vt links to each other with the input Si of amplifying unit (3), and the output end vo of amplifying unit (3) links to each other with the grid G of driven insulated-gate power device (4).

Innovation of the present invention is: also comprise self-supporting power (2) in the composition of driver, thereby no longer need the accessory power supply of any peripheral hardware.Self-supporting power (2) is formed the halfwave rectifier filter by diode D1 and capacitor C 1.The positive pole of D1 is as the input Pi of self-supporting power (2), also the secondary output end Vt with transformer (1) joins, join as the output Po of self-supporting power (2) and the power end Vcc of amplifying circuit (3) behind the negative pole of the last termination D1 of C1, the lower end of C1 is as the common port COM of circuit.

Amplifying unit (3) is made up of triode T1, T2 and diode D2, D3, and the level of penetrating of NPN pipe T1 and PNP pipe T2 is connected together as amplifying unit (3) that is output end of driver Vo of the present invention; The negative pole of D2 is connected with the base stage of T1, and the positive pole of D2 and the base stage of T2 connect together as the input Si of amplifying unit (3); The collector electrode of T1 is as the power end Vcc of amplifying unit (3); The positive pole of D3 is connected with the collector electrode of T2, and the negative pole of D3 is common port COM.

The rectangular pulse modulation signal of prime output is added in the elementary of transformer (1), through transformer (1) isolate the back, modulation intelligence (being the rising edge and the trailing edge information of rectangular pulse) in its pulse signal is exaggerated unit (3) and receives, after amplifying in order to driving insulated-gate power device (4).Most of energy in the pulse signal of prime output, was received the back by self-supporting power (2) and uses for amplifying unit (3) by the isolation transmission of transformer (1) in the flat-top stage of rectangular pulse

Compared with prior art, advantage of the present invention is:

[1]. do not need independent power supply;

[2]. circuit is simple;

[3]. because circuit is simple, can accomplish the time of delay of driving in tens ns;

[4], output stage belongs to active push-pull structure, thereby has precipitous rising edge and trailing edge, when driving four IRF360, only needs tens ns can open them;

[5]. because circuit is simple, excess loss is little, thereby efficient height just can drive four high-power V metal-oxide-semiconductors the IRF360 by a pulsewidth modulated intergrated circuit (as SG3525 etc.).

Accompanying drawing 1 is the half-bridge driver that only is suitable for driving the transformer isolation of small-power insulated gate device, and this is a known prior art.

Accompanying drawing 2 is block diagrams of the isolated VMOS insulated-gate power device driver of Chinese patent CN1070069A announcement.

Accompanying drawing 3 is one embodiment of the present of invention.

The present invention is described in further detail below in conjunction with the indefiniteness embodiment of accompanying drawing 3.

The pulse transformer (1) that is coupled among Fig. 3 is made of miniature ferrite transformer, and input signal is added in the elementary of it, and secondary lower end is common port COM, and the upper end is the output (Vt) of transformer (1).Self-supporting power (2) is formed the halfwave rectifier filter by diode D1 and capacitor C 1, and just very self-supporting power (2) the input Pi of D1 links to each other with the secondary output end Vt of transformer (1); The upper end of C1 is connected the output Po of back as self-supporting power (2) with the negative pole of D1; The lower end of C1 also is common port COM.Amplifying unit (3) is made up of triode T1, T2 and diode D2, D3, and the level of penetrating of NPN pipe T1 and PNP pipe T2 is connected together as amplifying unit (3) that is output end of driver Vo of the present invention; The negative pole of D2 is connected with the base stage of T1, and the positive pole of D2 and the base stage of T2 connect together as the input Si of amplifying unit (3), and this end also links to each other with the secondary output end Vt of transformer (1); The collector electrode of T1 is as the power end Vcc of amplifying unit (3), with the output of self-supporting power (2) just the upper end Po of capacitor C 1 link to each other; The positive pole of D3 is connected with the collector electrode of T2, and the negative pole of D3 also is common port COM.Load unit (4) is driven VMOS pipe, and its grid G links to each other with the output end vo of amplifying unit (3), and its source electrode also is common port COM.The common port COM of unit 1 to 4 connects together.In amplifying unit (3), triode T1 and T2 constitute complementary plug-type amplifying circuit, and two Guan Jun work in the emitter follower state; Diode D2 and D3 are the reverse isolation pipe, when the signal of the secondary output end Vt of pulse transformer (1) output when negative, D2 prevent T1 pipe emitter junction reverse breakdown may, D3 prevents the collector junction forward conduction of T2 pipe.

Half-wave rectifying circuit is the rectification circuit of capacitor filtering, and this rectification circuit belongs to peak rectifier circuit, and promptly rectifier diode only just begins conducting during near peak value at input voltage.During operate as normal, maintain the slightly direct voltage of ripple on the capacitor C 1 of self-supporting power (2), its value is a little less than the peak value of the secondary output end output signal of pulse transformer (1).In the rising edge AB of input signal section, because the voltage on the capacitor C 1 is higher than the voltage on the secondary output end Vt of pulse transformer (1), not conducting of rectifier diode D1, input modulating signal only need provide the triggering signal of faint power, by pulse transformer (1), be sent to triode T1 through diode D2 again and amplify, export precipitous rising edge drive signal, open power tube T3.After the B point, the input signal amplitude is higher than the voltage on the capacitor C 1, diode D1 conducting, capacitor C 1 charging, provide amplifying circuit (3) required energy, the required energy of amplifying unit (3) is mainly provided by pulse transformer (1) by input modulating signal in the flat part CD of input signal section.In the trailing edge DE of input signal section, not conducting of D1, input modulating signal still only provides triggering signal, by transformer (1) make triode T2 conducting immediately and the grid capacitance Cgs of driven power tube T3 of releasing rapidly on electric charge, thereby switch-off power pipe T3.Crucial part of the present invention just is that at the rising edge and the trailing edge of input signal, input signal only provides the triggering signal of micropower by pulse transformer (1), thereby the output drive signal delay seldom, and distortion is atomic; The required energy of amplifying circuit is mainly provided by transformer (1) in the flat part CD of input signal section, because power output is arranged, waveform will slightly distort, but this segment signal has distortion that driving power pipe T3 is had no effect slightly.

The last thing that notes in some enforcement of mentioning again:

[1]. driven also can be other insulated-gate power device, and as IGBT (insulated gate bipolar power tube), at this moment, output end of driver Vo should connect the grid of IGBT pipe, and the common port COM of driver connects its emitter.

[2]. the diode D1 in the self-supporting power (2) can omit (disconnect, all the other connections need not become), and the rectifying tube utilization of self-supporting power is the series connection of collector junction and the diode D2 of triode T1 at this moment.

Claims

1. the driver for isolating of an insulated gate device, it provides isolation by coupling pulse transformer (1), is used to drive insulated-gate power device (4) after the triggering signal that transformer (1) is transmitted by amplifying unit (3) is amplified, and it is characterized in that:

The composition of driver also comprises a self-supporting power (2), it forms the halfwave rectifier filter circuit by diode D1 and capacitor C 1, wherein the positive pole of D1 is as the input Pi of self-supporting power (2) and meet the secondary output end Vt of transformer (1), as the output Po of self-supporting power (2), the lower end of C1 is as the common port COM of circuit behind the negative pole of the last termination D1 of C1;

The secondary output end Vt of transformer (1) not only with the input Pi of self-supporting power (2), be that the positive pole of diode D1 links to each other, also the input Si with amplifying unit (3) links to each other; The output Po of self-supporting power (2), be that the upper end of capacitor C 1 links to each other with the power end Vcc of amplifying unit (3); The output end vo of amplifying unit (3) links to each other with the grid G of driven insulated-gate power device (4).

2. the driver for isolating of insulated gate device according to claim 1 is characterized in that:

3. the driver for isolating of insulated gate device according to claim 1 and 2 is characterized in that:

Driven insulated-gate type device can also be the IGBT power tube except that the VMOS power field effect pipe; At this moment, output end of driver Vo should connect its grid, and the common port COM of driver connects its emitter.

4. the driver for isolating of insulated gate device according to claim 1 and 2 is characterized in that:

Rectifier diode D1 in the self-supporting power (2) also can save, and at this moment is to utilize the collector junction of the triode T1 in the amplifying unit (3) and the double rectifying tube of doing of polyphone of diode D2.