密勒运算跨导放大器的单粒子瞬变效应分析

Analysis of Single-Event Transients in Miller Operational Transconductance Amplifier

从2阶闭环系统的角度出发,推导并分析了单粒子瞬变(SET)电流在密勒运算跨导放大器(OTA)中的传导效应。通过理论分析,发现OTA两级跨导比例(Gm2/Gm1)的大小不仅决定了系统闭环的稳定性,也决定了SET电流在系统输出端电压响应的振动幅度和恢复时间。在标准0.18μm CMOS工艺下,通过改变两级跨导的比例值,对电路的两个有效节点进行电路级SET轰击实验,收集实验结果,给出抗SET效应运算放大器的设计建议。

Propagation of single-event transients （SET） in Miller operational transconductance amplifier （OTA） was extrapolated and analyzed based on a 2nd-order closed-loop system. It was found that the transconductance ratio of the two stages of OTA would affect damping factor, which affects not only stability of the OTA, but also swing of SET voltage response and recovery time at output of the OTA. Based on a standard 0. 18 μm CMOS process, SET simulations were made at circuit level by changing damping factor represented by transconductance ratio of the two stages. Experimental results were collected and recorded, which is helpful for radiation-hardening design of the OTA.