A high performance ROIC for a standalone monitoring system in IOT environments

Abstract

This chapter presents a low power consumption Read Out Integrated Circuit (ROIC) for conditioning and acquiring capacitive sensor signals that interfaces with a supervising system using frequency processing based architecture with high efficient frequency-to-digital converters with programmable resolution. The supervising system communicates with the world using an Ethernet bus interface. The precision module of the system is constituted by the ROIC that is designed using a temperature compensated voltage reference circuit (bandgap) coupled to a low power capacitance to frequency converter (CtoF). A controlled compensation of the channel length modulation effect and the suppression of mobility dependence reduce the consumption of the ROIC down to 26μA at half power supply. Furthermore, the temperature dependent coefficient achieved is only 16 ppm/ ◦C.