Abstract: The present invention is directed at improving charge transfer based measurement techniques. This may be done through the use of a sigma-delta like sensing circuit that continually removes a specific amount of charge from an accumulator to produce a binary bit output stream reflective of the state of a connected sensor. Further techniques include detection of a charge transfer measurement residual through a controlled, multi-step charge removal until a trip event is cleared, as well as the reuse of a voltage threshold with a plurality of charge transfers measurements of different resolution.

Abstract: An integrated circuit for compensating for parasitic capacitance in a capacitive measuring apparatus wherein a capacitance measurement is done by repeatedly transferring charge from a capacitor to be measured to a reference capacitor.

Abstract: A capacitive sensing circuit which has a uniformly resistive sense plate, a charge transfer measurement circuit connected to one side of the sense plate and a dummy load which is only connected to another side of the sense plate during some measurement cycles.