Patent ID: 8642938

Claim:
An apparatus, comprising: a photodiode to accumulate charge in response to light incident upon the photodiode; a first charge storage device; a first transfer transistor coupled between the photodiode and the first charge storage device to selectively transfer charge to the first charge storage device from the photodiode; a second charge storage device; a second transfer transistor coupled to between the photodiode and the second charge storage device to selectively transfer charge to the second charge storage device from the photodiode; an enable transistor coupled between the first charge storage device and a readout node coupled to the second charge storage device to selectively couple the first charge storage device to the readout node; and an amplifier transistor having a gate coupled to the readout node; wherein a signal at the readout node is representative of a sum of total charge stored in the first charge storage device and a total charge stored in the second charge storage device when the enable transistor is ON.