Front-end interfacing circuit for capacitive sensor

This paper presents an interfacing circuit for capacitive sensor using charge amplifier formed a capacitance-to-voltage converter. The proposed circuit is suitable for the front-end analog-to-digital converter (ADC) and wide variable range of sensing capacitance. The achieved output voltage provides a linear transfer characteristic and fast response. The circuit configuration is implemented using only commercially available devices. The performances of proposed circuit are confirmed by experimental results.