Abstract: A system for controlling a touch screen. A touch screen element having a plurality of contacts, such as one contact electrode at each of four corners. A multiplexer coupled to the touch screen element for forming a plurality of connections, such as various combinations of the contact electrodes to allow measurements to be made of the impedance of the touch screen element from the left side to the right side, from the top to the bottom, and do forth. A touch screen processor coupled to the touch screen element for determining an oscillation frequency of the touch screen element as a function of the electrode connections.

Abstract: A buffer amplifier and an associated method have been provided for slew rate and swing level control in the buffering of a signal. The method accepts an input signal having a voltage swing, a swing control signal, and a slew rate control signal. The voltage swing for each output in a set of serially-connected buffer stages is selected in response to the swing control signal. The selected voltage swing for a subset of buffer stages is modified in response to the slew rate control signal. Selecting the voltage swing for each output entails selecting a source current for each buffer stage. A bias current is generated and mirrored through a current source connected to each buffer stage. Modifying the selected voltage swing for each of the subset of buffer stages includes modifying the bias current to the subset of buffer stages.

Abstract: A buffer amplifier and an associated method have been provided for slew rate and swing level control in the buffering of a signal. The method accepts an input signal having a voltage swing, a swing control signal, and a slew rate control signal. The voltage swing for each output in a set of serially-connected buffer stages is selected in response to the swing control signal. The selected voltage swing for a subset of buffer stages is modified in response to the slew rate control signal. Selecting the voltage swing for each output entails selecting a source current for each buffer stage. A bias current is generated and mirrored through a current source connected to each buffer stage. Modifying the selected voltage swing for each of the subset of buffer stages includes modifying the bias current to the subset of buffer stages.