Noise Coupling Analysis from High Voltage Capacitor Discharging Circuit in an Electronic Safety and Arming Device

摘要

An electronic safety and arming (ESAD) system has a capacitor discharging circuit (CDC) to detonate a fuse. The CDC uses over thousands voltage to ensure the reliability of detonation. When a capacitor of CDC is discharged, a very high and broadband current discharged from the CDC causes noise coupling to noise-sensitive peripheral circuits. Therefore, in order to guarantee operational reliability of the ESAD, it is necessary to analyze noise coupling from the high current generated by the CDC. In this paper, we analyze noise coupling in the ESAD system. Noise coupling paths between CDC and trigger circuit are analyzed with full wave 3D-electromagnetic (EM) simulation. Also, simulation in the time domain is conducted to verify the voltage noise induced on the trigger circuit. We propose two ground designs to suppress noise coupling from the CDC. The effectiveness of the different ground designs is compared with time domain simulation. As a result, the proposed ground designs suppress the voltage noise induced on the trigger circuit up to 56 %.