An analog front-end for remote sensor applications with high input common-mode rejection including a 16bit ΣΔ ADC in 0.35μm 3.3V CMOS process

Data acquisition through remote sensors can be exposed to very high electrical noise sources because sensor wiring acts like antennas for noise. Aircraft are particularly exposed to EMI, RFI radiations and I×R ground loops. The chip ´OctAD-16´ has been designed for digitizing various DC and AC signals coming from onboard sensors with reduced loss of accuracy even with 150 V and several 100 MHz electrical aggressions. A standard 3.3 V CMOS process, without high voltage option, has been chosen to insure a long production life of the chip. In this paper, we describe the design solutions we have used to cope with such stringent requirements.