An interfacing circuit for differential capacitive sensor and its performance analysis

Abstract

This paper presents an interface circuit to measure various parameters in voltage mode by very small capacitance change in capacitive sensors. Differential capacitance comprises a capacitance-to-voltage conversion with low power, high speed and greater accuracy. Differential capacitance operation principle yields a high-precision measurement for capacitive sensors with increased signal-to-noise immunity. Double differential operating principle minimizes error caused by parasitic capacitance and stray capacitance of the sensor probes. Differential capacitance measurement comprises a capacitance-to-voltage conversion with low power, high speed and greater accuracy. Differential capacitance operation principle yields a high-precision measurement for capacitive sensors with increased signal-to-noise immunity. Double differential operating principle can also minimizes error caused by parasitic capacitance and stray capacitance of the sensor probes.