Design and Simulation of a MGy Radiation Tolerant Signal Conditioning Circuit for Resistive Sensors in 0.7 $\mu$ m CMOS

This paper presents the design and simulation results of a radiation tolerant configurable discrete time CMOS signal conditioning circuit for use with resistive sensors like strain gauge pressure sensors. The circuit is intended to be used for remote handling in harsh environments in the International Thermonuclear Experimental fusion Reactor (ITER) (experimental validation still needs to be performed). The design features a 5 V differential preamplifier using a Correlated Double Sampling (CDS) architecture at a sample rate of 20 kHz and a 24 V discrete time post amplifier. The gain is digitally controllable between 27 and 400 in the preamplifier and between 1 and 8 in the post amplifier. The nominal input referred noise voltage is only 8.5 $\mu {\rm V}_{\rm \rms}$ while consuming only 1 mW. The circuit has a simulated radiation tolerance of more than 1 MGy.