US 12,216,861 B2
Capacitive touch control system with frequency booster
Sung-Han Wu, Hsin-Chu County (TW)
Assigned to PIXART IMAGING INC., Hsin-Chu County (TW)
Filed by PixArt Imaging Inc., Hsin-Chu County (TW)
Filed on Jul. 21, 2023, as Appl. No. 18/224,587.
Application 18/224,587 is a continuation of application No. 17/739,768, filed on May 9, 2022, granted, now 11,747,939.
Prior Publication US 2023/0359304 A1, Nov. 9, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. G06F 3/041 (2006.01); G06F 3/044 (2006.01)
CPC G06F 3/04166 (2019.05) [G06F 3/044 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A capacitive touch control system, comprising:
a touch panel;
an analog front end, configured to receive a low frequency signal from the touch panel, and comprising:
a frequency booster, configured to perform frequency adjustment on the low frequency signal using a reference frequency, wherein when the touch panel is touched by a touch pen, the reference frequency is controlled to be variable;
an operational amplifier, coupled to an output of the frequency booster, and having an inverting input end coupled to the frequency booster and a non-inverting input end; and
a gain capacitor coupled between the frequency booster and the inverting input end of the operational amplifier.