Low power voltage sensing through capacitance to digital conversion

Abstract

Capacitance sensors are widely used for sensing physical parameters. Conventional capacitance to digital methods use complex analog ADC techniques which are power hungry. Recently a fully digital solution was proposed with improved power consumption. This paper describes a number of problems in that solution, analyzes these problems, and proposes a new design free of these problems. A voltage senor as an example was designed based on the proposed capacitance to digital conversion in this paper. The new method achieves the same accuracy with less than half the circuit size, and 25% and 33% savings on power and energy consumption.