粒子探测器读出电路漏电流自适应补偿结构

An Adaptive Leakage Current Compensation Structure for Particle Detector Readout Circuit

在深亚微米工艺下,用于粒子探测器信号读出的电荷灵敏放大器(CSA)存在栅极漏电流,这不仅会增加噪声,还会影响CSA输出端的直流工作电压。对以反馈电流镜为基础的CSA输入漏电流补偿电路进行改进。采用基于电流匹配的自适应电流偏置方式,该CSA能够自适应调节漏电流,补偿反馈管的偏置电流。将工作点锁定在预设值,使CSA输出端直流电压仅由片外设定值决定,不受漏电流的影响。该方法解决了外部调节带来的不便和调节过于灵敏的问题。

Gate leakage of charge sensitive preamplifier（CSA）for particle detector signal readout in deep submicron process not only increases the noise but also impacts the DC voltage of the amplifier output.A CSA input leakage current compensation circuit structure based on feedback current mirror had been improved.The bias current of the feedback MOSFET in the input leakage current compensation structure could be adjusted adaptively by means of an adaptive adjusting technique based on current matching.The operating point could be locked at the required value,so that the CSA output DC voltage was decided only by the external bias and not sensitive to the leakage current.This method had solved the problems of the inconvenience and too high sensitivity with respect to the external adjustment.