Patent ID: 11914831
Assignee: SHENZHEN GOODIX TECHNOLOGY CO., LTD.
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 14:
15. A method for self-capacitor sensing in a touch panel, the method comprising:
charging a self-capacitor of the touch panel for a first time period by coupling the self-capacitor to a source voltage, the self-capacitor having a first capacitance in absence of a local touch event on the touch panel and having a second capacitance in presence of the local touch event on the touch panel, the second capacitance being different from the first capacitance; and
discharging the self-capacitor to a discharge level for a second time period subsequent to the first time period by:
coupling the self-capacitor to a ramp-controlled current source; and
biasing the ramp-controlled current source to generate a discharge current that transitions from a high discharge current at a start of the second time period to a low discharge current at an end of the second time period based on a ramping transition profile,
such that the discharge level represents a first amount of remaining charge in absence of the local touch event and a second amount of remaining charge in presence of the local touch event, the first and second amounts of remaining charge being different; and

outputting a sense signal based on the discharge level for a third time period subsequent to the second time period.