再指出一个概念上的问题：

"确实死区时间是为了防止共态，也确实是防止体二极管损坏"
死区时间是防止MOSFET上下桥臂共态导通 不是防止体二极管损坏
反而过大的死区时间会使没有被屏蔽的体二极管流过过大电流
同时加上体二极管的较慢回复特性 会让体二极管共态损坏

引用一段作者原文：
A high Q resonant circuit such as a Tesla Coil is capable of storing considerable energy in its inductance and self capacitance. Under certain tuning conditions, this causes the current to "free-wheel" through the internal body diodes of the MOSFET devices as one MOSFET turns off and the other device turns on. This behaviour is not a problem in itself, but a problem arrises due to the slow turn-off (or reverse recovery) of the internal body diode when the opposing MOSFET tries to turn on.

MOSFET body diodes generally have a long reverse recovery time compared to the performance of the MOSFET itself. If the body diode of one MOSFET is conducting when the opposing device is switched on, then a "short circuit" occurs similar to the shoot-through condition described above.

This problem is usually eased by the addition of two diodes surrounding each MOSFET. Firstly, a Schottky diode is connected in series with the MOSFET source. The schottky diode prevents the MOSFET body diode from ever being forward biased by the free-wheeling current. Secondly, a high speed (fast recovery) diode is connected in parallel to the MOSFET/Schottky pair so that the free-wheeling current bypasses the MOSFET and Schottky completely.

This ensures that the MOSFET body diode is never driven into conduction. The free-wheel current is handled by the fast recovery diodes which present less of a "shoot-through" problem.

原文中黑体字明确指出 MOSFET的体二极管有着较慢的恢复时间
这样会直接导致上下桥臂的短路

所以作者在这里 使用了串联肖基特 并联快恢复二极管的方式 大大减小了反向电流通过MOSFET的体二极管
防止了MOSFET损坏 实际证明这是在大功率感性负载下很好的提高MOSFET性能的方式
原理图如下：



同时关于过大的死区时间带来的另一个问题 下楼列出