Patent ID: 11954286
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 array integrated with a display panel, the touch panel array having a plurality of channels, each having a respective channel self-capacitance that includes a respective base self-capacitance corresponding to display noise capacitively coupled onto the channel from the display panel and a respective touch capacitance that changes responsive to presence of a touch event local to the channel, the system comprising:
a voltage input (Vin) node coupled with a channel of the plurality of channels, such that Vin represents a voltage across the respective self-capacitance (Ci) of the channel;
a discharge stage configured to couple the Vin node with a locally noise-suppressed discharge current (Iout) for a discrete discharge time during a discharge phase to discharge the Vin node to a discharge voltage level, such that the discharge voltage level is a first voltage level in absence of a touch event local to the channel and is a second voltage level in presence of the touch event local to the channel,
wherein the Iout is generated by iterating sequentially through M configurations of M current sources, M being an integer greater than 1, and in each mth configuration of the M configurations, generating the Iout based on a sum of currents through M−1 of the M current sources other than an mth of the M current sources; and
a sensing stage coupled with the discharge stage to output a voltage output (Vout) for the channel by passively mixing at least the discharge voltage level to produce a pair of up-converted channel signals, sampling the pair of up-converted channel signals to obtain a differential voltage sample, and amplifying the differential voltage sample to generate the Vout as indicating absence or presence of the touch event local to the channel.