Patent ID: 8854059

Claim:
An apparatus comprising: a capacitive touch screen panel; an active gain control circuit having: an amplifier that is coupled to the capacitive touch screen panel; a switch that is coupled to the capacitive touch screen panel; and a first switching circuit that is coupled to the amplifier and the switch; a successive approximation register (SAR) analog-to-digital converter (ADC) having: a capacitor bank that is coupled to the first switching circuit, wherein the capacitor bank includes a plurality of weighted capacitors that are coupled in parallel with one another between the first switching circuit and a node, wherein the node is located within the SAR ADC; a comparator that is coupled to the node; SAR logic that is coupled to the comparator; and a second switching circuit that is coupled to the first switching circuit and that is controlled by the SAR logic; and an active gain, wherein the node further comprises a first node, and wherein the capacitive touch screen panel further comprises a plurality of sensing capacitors that are arranged in an array having a plurality of rows and a plurality of columns, wherein each column is associated with at least one of a plurality of second nodes, and wherein each sensing capacitor for each column is coupled to its associated second node, wherein the first switching circuit further comprises: a plurality of first switches, wherein each first switch is coupled between at least one of the second nodes and a third node; and a plurality of second switches, wherein each second switch is coupled between the third node and at least one of the plurality of weighted capacitors, wherein the third node is part of the capacitive touch screen panel.