Design and Implementation of an Interfacing Circuit for
Capacitive Sensor

Abstract

Increasing demand for automation in the industry as well as in daily life usable things has boosted the use of the sensor. These mems based motion sensor, mainly the capacitive one is extensively adopted for the automation process. This is due to, they are comparatively smaller in size and consumes less power than others. We prefer capacitive sensor as a sensing element as it offers high sensitivity, low noise performance and possesses lower
sensitivity towards temperature variation. Sensors outputs are usually very low in amplitude as well as highly susceptible to the various form of noises imposed by surroundings and components used for interfacing circuit. Therefore, for further processing of sensor output and to extract useful information from it, An Interfacing circuit is used that comprises of signal conditioning and signal processing units. So Here we have designed a signal
conditioning circuit for capacitive sensors based on Chopper modulation and charge sharing sensing technique on “VIRTUOSO” EDA tool provided by cadence using CMOS technology as well as on breadboard (hardware implementation) with discrete components. We compare between results obtained by hardware implementation and software simulations of respectively used techniques.