Apple Inc.
Touch sensor panel with multi-power domain chip configuration

Abstract:

A touch sensing system is disclosed. The touch sensing system includes a guard signal generation chip operating in a first power domain referenced to a first voltage, the guard signal generation chip configured to generate a guard signal. A touch sensing chip operates in a second power domain, different from the first power domain, referenced to the guard signal, the touch sensing chip configured to sense touch at one or more touch electrodes included in a touch sensor panel operating in the second power domain referenced to the guard signal, and the touch sensing chip a different chip than the guard signal generation chip. A voltage regulator is configured to selectively regulate a voltage of the guard signal at the touch sensing chip.