33.1 Overview

The Peripheral Touch Controller (PTC) acquires signals to detect a touch on the capacitive sensors. The external capacitive touch sensor is typically designed as part of the printed circuit board (PCB) layout, and the sensor electrodes are connected to the analog front end of the PTC through the I/O pins of the device. The PTC supports both self and mutual capacitance sensors.

In the Mutual Capacitance mode, sensing is done using capacitive touch matrices in various X-Y configurations, including indium tin oxide (ITO) sensor grids. The PTC requires one pin per X-line and one pin per Y-line.

In the Self Capacitance mode, the PTC requires only one pin (Y-line) for each touch sensor.

The number of available pins and the assignment of X- and Y-lines is depending on both package type and device configuration. Refer to the Configuration Summary and I/O Multiplexing and Considerations sections for further details.