Patent ID: 8368409

Claim:
An apparatus comprising: a capacitive touch screen panel; and a touch screen panel controller having a precharge phase, a measurement conversion phase, wherein the touch screen panel controller includes: a capacitor bank that includes a plurality of weighted capacitors that are coupled in parallel with one another to a node; a first switching circuit that is coupled to the capacitive touch screen panel, wherein the first switching circuit is configured to precharge at least a portion of the capacitive touch screen panel during the precharge mode, and wherein the first switching circuit is configured to couple the portion of the touch screen panel to the capacitor bank during the measurement phase; a comparator that is coupled to the node; successive approximation register (SAR) logic that is coupled to the comparator; and a second switching circuit that is coupled to the first switching circuit and the capacitor bank, wherein the second switching circuit is controlled by the SAR logic during the conversion phase, and wherein at least a portion of the second switching circuit is activated during the precharge phase.