一类隔离驱动电路的“剩余驱动”问题

"Residual Driving" Problem of a Kind of Isolated Driving Circuits

讨论直流变换器中将脉宽调制器(PWM)输出与受控MOS管栅极连接的一类开关驱动电路.专注于分析它在PWM电路关闭后对栅极产生的驱动信号,被命名为"剩余驱动".描述这类剩余驱动的电气特性,说明它对变换器造成的危险,提出改进这类驱动电路以消除这些危险的4种方法.

We discussed a kind of isolated driving circuits for connecting the output of PWM integrated circuit with the gate of MOSFET controlled is discussed with the emphasis on analysis of the driving signal for the gate when the PWM has shuted down after normal operating.This driving signal is called ＂Residual Driving signal＂ in this paper.Its electrical characteristics are analyzed,the dangers of the signal to the converters are described.In order to eliminate these dangers,four methods for improving the driving circuits are proposed.The effects of these methods are observed by simulation,and have been adopted in our products.