Patent Document ID: 9166621
Application ID: 13917528
Patent Flag: 1

Claim One:
1. A method comprising: measuring a mutual capacitance on a sense element of a matrix-scanning device using a modulation circuit, wherein the matrix-scanning device comprises a plurality of drive lines and a plurality of sense lines and the sense element is located at an intersection of one of the plurality of drive lines and one of the plurality of sense lines, wherein the measuring the mutual capacitance comprises: applying a drive signal to the one of the plurality of drive lines using an excitation source; and sensing, by the modulation circuit, the drive signal on the one of the plurality of sense lines to measure the mutual capacitance of the sense element; and switching the sense element to be coupled and decoupled to a capacitor of the modulation circuit using a first plurality of switches, wherein the first plurality of switches are controlled by a clock; converting the mutual capacitance measured on the sense element to a first digital value; measuring a self-capacitance on at least one of the plurality of drive lines; switching the at least one of the plurality of drive lines to be coupled and decoupled to the capacitor using a second plurality of switches, wherein the second plurality of switches are controlled by the clock; and converting the self-capacitance measured on the at least one of the plurality of drive lines to a second digital value.