Ultra-low temperature dependent ROIC for capacitive sensing platforms

This paper presents a very low power consumption readout integrated circuit (ROIC) for conditioning and acquiring raw sensors signals for a frequency based converter platform with high resolution. The platform consists of specific circuits designed to interface capacitive sensors with high efficient frequency to code converters powered by a high performance voltage reference circuit. Thanks to a controlled compensation of the channel length modulation effect and the suppression of mobility dependence, it presents a low power consumption (26 μA at half power mode) and the temperature dependent coefficient achieved is only 16 ppm/°C. In frequency acquisition techniques the ROIC is precise and versatile. In scalable signal sensor acquisition structures, it improves the system reliability and performance.