桥式驱动功率MOSFET的电磁干扰与抑制

为解决功率MOSFET因栅极驱动信号振荡产生的过热损坏问题，从MOSFET的模型入手，给出了考虑驱动电路各寄生参数的半桥逆变电路等效模型．深入分析了栅极振荡的产生机理，推导了各参数与振荡之间的关系表达式，绘制了以各参数为自变量的振荡三维时域暂态关系曲线，并以此为依据进行参数优化设计，通过增加MOSFET开通时间，最大程度地抑制振荡。理论分析和实验结果表明，改进后的驱动电路简单、实用，实现了系统的安全稳定运行。

Electromagnetic Interference of Power MOSFET with Bridge Drive and Its Suppression

In order to eliminate the osc il lation of the MOSFET gate, a circuit model of the half-bridge inverter consider ing stray parameters of the drive circuit is put forward based on the MOSFET mod el. By analyzing the circuit topology the oscillation is caused by the high d v /d t produced during the power MOSFET switching and junction capacitance a nd distributed inductance. The drive circuit parameters are devised according to the transient timing domain three-dimensional relationship curves of parameter s responding to the oscillation. The oscillation can be obviously suppressed wit h enhancing MOSFET turn-on time. Both the theoretical analysis and experimental results indicate that the improved circuit can meet the MOSFET drive requiremen t.