Patent ID: 6148670
Filing Date: 2000-11-21
Classification: G01P

Abstract:
A method for measuring changing capacitance of a plurality of differential capacitors, wherein common electrodes of each differential capacitor are coupled, the method comprising the steps of, for each of the plurality of differential capacitors:applying a first input voltage to a first non-common electrode of each differential capacitor and a second input voltage to a second non-common electrode of each differential capacitor;latching a first output voltage of the common electrodes onto one of a plurality of demodulators;applying the first input voltage to the second non-common electrode of a selected one of the differential capacitors, and applying the second input voltage to the first non-common electrode of the selected differential capacitor;applying a second output voltage of the common electrodes to the demodulator; anddetermining the change in capacitance of the differential capacitor from the first output voltage and the second output voltage;wherein a different demodulator is activated for each of the plurality of differential capacitors.