Patent Document ID: 9494628
Application ID: 14037098
Patent Flag: 1

Claim One:
1. A capacitance measurement circuit comprising: a capacitance to current conversion circuit configured to operate in a self capacitance mode in a first operational state and configured to operate in a mutual capacitance mode in a second operational state; and a current to code conversion circuit configured to output a digital value representative of a current generated by the capacitance to current conversion circuit; wherein: when the capacitance to current conversion circuit is configured to operate in the self capacitance mode, the capacitance to current conversion circuit comprises a sense capacitor between a first voltage potential and a plurality of switches, wherein the plurality of switches are configured to couple the sense capacitor alternately to a second voltage potential and to the current to code conversion circuit; and when the capacitance to current conversion circuit is configured to operate in the mutual capacitance mode, the capacitance to current conversion circuit comprises a sense capacitor between a first electrode and a second electrode, the first electrode is coupled to an alternating voltage signal, and the second electrode is coupled to the current to code conversion circuit.