Fly-Back原边控制芯片中负电流的影响和防护

The influence and protection of negative current in Fly-Back primary controller

首先阐述了在Fly-Back原边控制芯片中负电压和负电流的产生机理,以及芯片内部寄生双极晶体管对负电流的连锁反应机理,并以NPN带隙基准电压源为例分析了负电流对芯片可能造成的影响,最后提出了一系列在芯片内部可以采取的防护措施。

Firstly, described the generation theory of negative voltage and negative current in Fly-Back primary controller, and the theory of chain reaction caused by inner parasitic bipolar transistor; and then analyzed the influence of negative current in chip level with an example of NPN bandgap voltage reference; finally, proposed a series of action list of how to protect negative current in chip level.