复杂电磁环境下RS422接口保护电路的实现

Design and Achieve for a Kid of Protection Electrocircuit to RS422 Interface

在复杂电磁环境下如果对422通信接口进行带电热插拔操作会引发高电压冲击,当热插拔瞬间放电电流大于串口芯片所能承受的最大电流时,串口通信接口电路会被烧毁,为了有效保护通信接口电路,介绍了一种的串口热插拔保护电路,它的原理是使用对地二极管将瞬态的高电压抑制下来,在不改动设备的前提下可以对422通信接口电路提供有效的保护。经实践证明对RS422接口电路有明显的保护作用,也可以应用于其他串行通信电路。

In the complicated electromagnetic environment,if the RS422 serial interface was disconnectted when it is working,it cause high voltage surge′s impact to the serial interface.When the voltage is higher than the voltage that the chip coule support,the chip will be injured.To protect the serial interface we design the electric circuit,Its principle is the function of Diode′s instantaneous inhibition to the Voltage.When the high voltage was happen,it put a efficacious protection to 422 interface and it will not bring change to the Equipment.After the electric circuit was used,the RS422 serial interface would not be injured and the electric circuit have the same function to other serial communication electric circuit.