Apple Inc.
Multiple Controllers for a Capacitive Sensing Device

Abstract:

A capacitive sensing device can include multiple capacitive sensors. A first device controller is operatively connected to a portion of the capacitive sensors, while a second device controller is operatively connected to another portion of capacitive sensors. A common node or shield can be connected between the first device controller and the second device controller. Charging and discharging events of selected drive lines in the capacitive sensing device and/or of the common node or shield can be synchronized to reduce undesirable effects such as noise and/or to prevent the charging events and the discharging events from overlapping with each other. One or more reference capacitive sensors can be shared by the multiple device controllers.