A Programmable Capacitance-to-Voltage Converter for MEMS Capacitive Sensors

A Programmable Capacitance-to-voltage converter for MEMS capacitive sensors is proposed. The main circuit consists of balance capacitor arrays, capacitance transimpedance amplifier, sample/hold, low pass filter, and output buffer. Capacitance-to-voltage converter detects the change in capacitance between two capacitors and provides an output voltage proportional to it, with a capacitance resolution of 1.70 aF/√Hz at bandwidth of 500 Hz. The converter has advantages of tuning the gain, bandwidth, feedback capacitor, balance capacitor and output offset. It can be used as a general circuit for the application on a variety of MEMS capacitive sensors.