US Patent 11917316 Image sensor including pixel circuits

A circuit is provided and includes first to second switching units, a sensing unit, and first to second capacitive units. The first switching unit and the second switching unit are alternately turned on in response to, respectively, a first control signal and a second control signal that have different voltage levels. First terminals of the first and second switching units are coupled to each other. A sensing unit generates a sensing voltage, in response to light, at the first terminals of the first and second switching units. The first capacitive unit generates a first voltage, in response to the sensing voltage, at a second terminal of the first switching unit. The second capacitive unit generates a second voltage, in response to the generating the sensing voltage, at a second terminal of the second switching unit.