US 12,476,621 B2
Photoelectric sensing device for cancellate crosstalk
Dar-Chang Juang, Hsinchu (TW); and Hung-Jui Ting, Hsinchu (TW)
Assigned to ELITE SEMICONDUCTOR MICROELECTRONICS TECHNOLOGY INC., Hsinchu (TW)
Filed by ELITE SEMICONDUCTOR MICROELECTRONICS TECHNOLOGY INC., Hsinchu (TW)
Filed on Nov. 13, 2023, as Appl. No. 18/507,118.
Claims priority of application No. 112112230 (TW), filed on Mar. 30, 2023.
Prior Publication US 2024/0333264 A1, Oct. 3, 2024
Int. Cl. H03K 19/00 (2006.01); H03K 3/013 (2006.01); H03K 3/0233 (2006.01); H03K 17/96 (2006.01); H03K 19/0185 (2006.01)
CPC H03K 3/013 (2013.01) [H03K 3/02337 (2013.01); H03K 17/96 (2013.01); H03K 19/018514 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A photoelectric sensing device for canceling crosstalk, comprising:
a first capacitor;
a first switch coupled between a current source and the first capacitor and configured to turn on according to a driving signal and enable the current source to charge the first capacitor to generate a first capacitor voltage;
a second switch coupled between the first capacitor and an input terminal and configured to turn on according to a cancellation signal; and
a current-voltage conversion circuit coupled to the second switch and configured to receive an input current corresponding to a crosstalk signal and a non-crosstalk signal to generate a crosstalk voltage corresponding to the input current,
wherein, when the second switch turns on, the crosstalk voltage is subtracted from the first capacitor voltage to cancel the crosstalk signal, so as to output a sensing voltage;
wherein the current-voltage conversion circuit further comprises:
an operational amplifier having an inverting input terminal, a non-inverting input terminal and an amplified output terminal, the inverting input terminal being coupled to the second switch, and the non-inverting input terminal being coupled to a rated voltage;
a third switch coupled between the inverting input terminal and the amplified output terminal and configured to turn on or turn off according to a state of a reset signal; and
a second capacitor coupled between the inverting input terminal and the amplified output terminal and configured to generate the crosstalk voltage; and
wherein the amplified output terminal is further coupled to a sample-and-hold circuit comprising a fourth switch coupled between the amplified output terminal and a third capacitor, and the fourth switch turns on or turns off according to a state of a sample-and-hold signal to convert the sensing voltage into a digital signal.