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

Claim 0:
1. A system for self-capacitor sensing in a touch panel, the system comprising:
a touch panel interface to couple with a self-capacitor of a touch panel, 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;
a ramp-controlled current source;
an amplifier block; and
a phased switch controller coupled with a plurality of switches to:
control a first one or more switches, for a first time period, to charge the self-capacitor based on a source voltage;
control a second one or more switches, for a second time period subsequent to the first time period, to discharge the self-capacitor to a discharge level by biasing a 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.