Many touch sensing devices utilize capacitive sensing technology to detect a presence of an object in contact with or proximate to a touch screen panel or button, for example, by identifying a change in capacitance in the touch screen panel or button associated with the presence of the object. There are two main types of capacitive touch sensing technology, mutual capacitance and self-capacitance. In mutual capacitive touch screen devices, every row-column pair in the touch screen panel may form a capacitive sensor that can be separately measured. For example, in measuring a 4-by-4 matrix of electrodes forming a mutual capacitive sensor array, each row can receive a separate excitation signal from a control device, and each column can output a separate signal corresponding to the capacitance of the respective capacitive sensors.
A self-capacitance sensing device can include one or more self-capacitive sensors to detect whether a conductive object is proximate to the self-capacitive sensor, for example, in a self-capacitive touch screen panel, each row and each column can be separate self-capacitive sensors. To detect a touch proximate to the self-capacitance device, the control device coupled to the self-capacitive sensors can separately sense a capacitance of each self-capacitive sensor. While self-capacitance and mutual-capacitance schemes can effectively resolve a touch condition on their corresponding touch screen panels or array of buttons, they both utilize a 1-to-1 sensor-to-pin ratio in their capacitance sensing operations. As a number of buttons supported by a control device increases, a number of pins that the control device utilizes to sense the capacitance of the capacitive sensors corresponding to the buttons also increases.