Base capacitance compensation for a touchpad sensor

摘要

For a compensation to the sensed capacitive values of a touchpad sensor, the variance profile of the base capacitance or the sensed capacitive values of the traces in the touchpad sensor is determined, and then a firmware operation based on the variance profile is carried out to modify the sensed capacitive values or the position value when an object touches on the touchpad sensor, such that the touchpad sensor operates as a symmetrical touchpad sensor does.