Magnetic isolation grid driver

Abstract

A magnetic isolation grating driver includes a driver generating pulse width variable signals, a pulse isolation transformer, an input capacitor serial to the input of the transformer, an output capacitor serial to output of the transformer, an output diode parallel to the output of the magnetic isolation grating driver, output small power MOS fieldistor serial to the capacitor of the output which source is connected with a terminal of the transformer output and the grating to the other, the transformer output , the output capacitor, the diode and the MOS fieldistor make up of a serial circuit.

Description

(1) Technical field [0001] The invention relates to a magnetically isolated driver, in particular to a magnetically isolated gate driver provided with a power metal oxide semiconductor field effect transistor so as to have better transient characteristics. (2) Background technology [0002] Magnetically isolated drivers can be used to drive high-end power MOSFETs. A commonly used driver circuit such as figure 1 shown. The capacitor C1 is the DC isolation capacitor at the input terminal, and the reference direction of the capacitor voltage is as follows: figure 1 As shown, T1 is an isolation transformer, QM is a driven MOSFET, and C3 is an equivalent input capacitance of QM. S1 is the output signal waveform of the pulse width modulation driver (PWM Driver), S2 is the waveform at the input end of the transformer, and S3 is the output waveform of the magnetic isolation driver. figure 1 For the working waveform of the circuit shown, please refer to figure 2 As shown, assum...

AI Technical Summary

Problems solved by technology

Therefore, this kind of drive circuit does not have better transient characteristics, and when the power supply is turned on and off, it will cause false conduction of the switch tube, which may cause the failure of the entire power supply.

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