US 12,436,644 B2
Capacitive sensor driving scheme for minimizing peak-to-average-power ratio
Tracy Scott Dattalo, Los Gatos, CA (US)
Assigned to Synaptics Incorporated, San Jose, CA (US)
Filed by Synaptics Incorporated, San Jose, CA (US)
Filed on Mar. 6, 2024, as Appl. No. 18/597,034.
Prior Publication US 2025/0284364 A1, Sep. 11, 2025
Int. Cl. G06F 3/041 (2006.01); G06F 3/044 (2006.01)
CPC G06F 3/0418 (2013.01) [G06F 3/044 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A system, comprising:
a plurality of sensor electrodes; and
a processing system, wherein the processing system is configured to:
drive sensor electrodes of the plurality of sensor electrodes with sensing signals corresponding to a plurality of frequencies;
adjust, while driving the sensor electrodes of the plurality of sensor electrodes with the sensing signals, instantaneous phases of the sensing signals, wherein adjusting the instantaneous phases of the sensing signals comprises increasing a phase of a first phasor corresponding to a first sensing signal for a first transmitter electrode of a pair of sensor electrodes while decreasing a phase of a second phasor corresponding to a second sensing signal for a second transmitter electrode of the pair of sensor electrodes; and
obtain, via at least one sensor electrode of the plurality of sensor electrodes, resulting signals corresponding to the sensing signals, wherein the resulting signals are indicative of one or more of presence, position, motion, or features of one or more input objects;
wherein the processing system is configured to constrain a sum of the first and second phasors to be within a maximum magnitude;
wherein the processing system is configured to adjust the instantaneous phases of the sensing signals such that, while driving the sensor electrodes with the sensing signals, the first phasor rotates clockwise while the second phasor rotates counterclockwise;
wherein the processing system is further configured to adjust the instantaneous phases of the sensing signals such that, while driving the sensor electrodes with the sensing signals, the first and second phasors each reverse rotation upon a sum of the first and second phasors reaching the maximum magnitude at a point where the first and second phasors have the same phase;
wherein prior to the first and second phasors reversing rotation, the clockwise rotation of the first phasor and the counterclockwise rotation of the second phasor causes the sum of the first and second phasors to increase; and
wherein after the first and second phasors reverse rotation, the first phasor rotates counterclockwise and the second phasor rotates clockwise, and the counterclockwise rotation of the first phasor and the clockwise rotation of the second phasor causes the sum of the first and second phasors to decrease.