Please help me analyze the working principle of MOSFET drive circuit

Larry.xu

Please help me analyze the working principle of MOSFET drive circuit [Copy link]

I need an expert to analyze the working principle of MOSFET drive circuit. My analog electronics knowledge is too poor.

maychang

There are two "grounds" in this figure, one is marked as "PGND", and the other is not marked (connected to pin 4 of the chip), which is the negative terminal of the +15V power supply. These two "grounds" must be electrically connected together.

天天1

maychang posted on 2018-9-16 12:02 There are two "grounds" in this picture, one is marked as "PGND", and the other is not marked (connected to the chip's 4th pin), which is the negative end of the +15V power supply. These two " ...

May I ask what this R79 10 ohm electronic is for? I don't understand it

maychang

天天1 Published on 2018-9-16 16:06 May I ask what this R79 10 ohm resistor is for? I don't understand it

This 10 ohm resistor can usually be left unused (short circuit). In each switching power cycle, when the output terminal (AX) changes from a high level (close to 48V) to a ground level, the 15V power supply will charge the capacitor CAH1 through R79 and D1. The purpose of R79 is to limit the charging current of the first charge. Usually, D1 will not use a diode as small as 1N4148, and CAH1 will not use a diode as large as 47uF, so there is no need to limit the first charge current.

qwqwqw2088

The OP uses a domestic half-bridge MOS gate driver. HIN input high level HO output high level LIN input low level LO output low level Please refer to the chip manual for details.

Larry.xu

maychang posted on 2018-9-16 12:02 There are two "grounds" in this figure, one marked as "PGND", and the other is not marked (connected to the chip's 4th pin), which is the negative end of the +15V power supply. These two " ...

PGND is the ground of the power part, connected to GND with constantan wire