Patent ID: 7663379

Claim:
A method of capacitance-to-voltage conversion with an external sensor capacitor and a capacitance-to-voltage converter implemented on an integrated readout circuit that includes a reference capacitor, a sampling capacitor and a sampling amplifier and has input terminals to which the sensor capacitor is connected to be in series with the reference capacitor, comprising the steps of: a) applying a reference voltage to the series connected sensor capacitor and reference capacitor, and charging the sampling capacitor to the potential at an interconnection node between the sensor capacitor and the reference capacitor; b) connecting the sampling capacitor to inputs of the sampling amplifier; c) applying the reference voltage to the series connected sensor capacitor and reference capacitor with a polarity opposite to that in step a), and charging the sampling capacitor to the potential at the interconnection node between the sensor capacitor and the reference capacitor; and d) connecting the sampling capacitor to the inputs of the sampling amplifier in a polarity opposite to that in step b).