High-Temperature 13-Bit Delta-Sigma ADC in Standard SOI CMOS Operating Up to 260°C

In this paper, we present a 1.8-V 2nd-order DeltaSigma ADC for high-temperature operation, featuring 13 bits of ENOB and 150 Hz of bandwidth at 260°C. The chip is designed with a 180-nm SOI CMOS process, pushed well beyond its temperature qualification limit of 175°C through ad-hoc design techniques. The junction and channel leakage currents dependence on the temperature are carefully assessed and their negative effects on circuit performance are compensated using clock boosting and dummy transistor techniques. The converter, which has been experimentally characterized up to 270°C, achieves excellent performance up to 260°C: a Signal-to-Noise Ratio of 86 dB and a Signal-to-Noise-and-Distortion Ratio of 82 dB have been measured within a bandwidth of 150 Hz and for an oversampling ratio of 512.