Ignition driving circuit

Abstract

The invention provides an ignition driving circuit, which comprises an input end, a photocoupler U1 and a VDMOS tube Q1, wherein an input signal of the input end is connected in series with a diode D1and a diode D2 via a resistor R1 and then connected to the positive end of a light emitting tube of the photocoupler U1, and the negative terminal of the light emitting tube is connected with the signal ground; a power source is connected in series with the resistor R2 and the resistor R3 and is connected to a photosensitive tube collector of the photocoupler U1, and the emission electrode of thephotosensitive tube is connected with the power ground; meanwhile, the power supply is subjected to voltage division through the resistor R2 and the resistor R3 and drives the grid electrode of the VDMOS tube Q1, and two reverse voltage regulators D3 and D4 are connected in series between the grid electrode and the source electrode of Q1; and a load resistor RL is connected in series between thedrain electrode of the VDMOS tube Q1 and the power ground. The ignition driving circuit in the invention is directed to the specific use requirements of the ignition system and the situation of the load grounding end, considering the isolation between the front and rear stages to improve the anti-interference ability of the circuit and designing an ignition circuit and the like with small packagesize and strong driving capability.

Description

technical field [0001] The invention relates to the design technology of a semiconductor hybrid integrated circuit, in particular to an ignition drive control type hybrid integrated circuit. Background technique [0002] The traditional ignition circuit is a contact ignition system, which has large size, low reliability, and poor anti-interference ability. The ignition status is greatly affected by the speed and technical status of the contacts, and requires frequent maintenance and adjustment. Therefore, it is of great significance to design an ignition drive circuit with small size, high reliability and strong anti-interference ability. [0003] The characteristic of the ignition drive control system is that the ignition work is realized by controlling the output pulse large current of the rear stage through the small signal of the front stage. In order to prevent the circuit from overheating and reduce the power consumption of the circuit, high-power tubes with large dri...

AI Technical Summary

Problems solved by technology

[0005] 1. There is no isolation between the input and output stages, and the anti-interference ability is poor

[0006] There is no electrical isolation between the input and output stages of the traditional ignition drive circuit, and the output of the latter stage generally has a large current, which is easy to interfere with the small signal control part of the previous stage, resulting in misoperation of the ignition system

[0007] 2. If the output uses a high-power three-stage tube, the switching dynamic loss is relatively large

[0008] The traditional ignition circuit uses a high-power three-stage tube as the output. The saturated conduction state has a large pressure drop, low work efficiency, and rapid temperature rise. It is necessary to install a heat sink to ensure its normal operation.

[0009] 3. When the N-channel VDMOS tube is output, it cannot meet the requirements of the load ground terminal

[0010] The power supply of the optocoupler-isolated output terminal is the same power supply as the output power supply. If the N-channel VDMOS tube structure is used as the output, the load is grounded, and the voltage between the gate and the source at the moment of conduction will not be able to maintain its conduction state.

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