According to one aspect, embodiments herein provide a unit cell comprising a photodiode, a MOSCap having an input node coupled to the photodiode, a reset switch selectively coupled between the MOSCap and a reset voltage, and a transistor coupled to the input node of the MOSCap, wherein, in a first mode of operation of the unit cell, the reset switch is configured in an open state and charge generated by light incident on the photodiode accumulates at the input node of the MOSCap in response to voltage at the input node being less than a threshold voltage, and wherein, in a second mode of operation of the unit cell, the reset switch is configured in the open state and the charge generated by the light incident on the photodiode accumulates on the MOSCap in response to the voltage at the input node being greater than the threshold voltage.