High dynamic range cmos image sensor pixel with reduced metal-insulator-metal lateral overflow integration capacitor reset settling

Abstract

A pixel circuit includes a transfer transistor coupled between a photodiode and a floating diffusion. A lateral overflow integration capacitor (LOFIC) includes an insulating region disposed between a first metal electrode coupled to a bias voltage source, and a second metal electrode selectively coupled to the floating diffusion. A multifunction reset transistor includes a gate, a drain, a first source, and a second source. The drain, the first source, and the second source are coupled to each other in response to a multifunction reset control signal turning the multifunction reset transistor on. The drain, the first source, and the second source are decoupled from one another in response to the multifunction reset control signal turning the multifunction reset transistor off. The drain is coupled to a reset voltage source, the first source is coupled to the first metal electrode, and the second source is coupled to the second metal electrode.