Patent ID: 8451348

Claim:
An image sensor, comprising: a photodetector; an output transistor having a gate coupled to receive a signal from said photodetector; a reset transistor having a drain coupled to reset a gate of said output transistor; a transfer transistor coupled to transfer said signal from said photodetector to said gate; a sample circuit coupled to receive an output signal from said output transistor; and, a control circuit that has a number of configurations including: a first configuration to switch said reset transistor to a first triode region such that said output transistor provides a sampled first reference output signal; a second configuration to switch said reset transistor to a first OFF state and said transfer transistor to a second triode region such that said output transistor provides a sampled common reset output signal; a third configuration to switch said transfer transistor into a second OFF state so that said output transistor provides a sampled first sense-node reset output signal; a fourth configuration to switch said sample circuit to sample and store said sampled first reference output signal when said reset transistor is in said first triode region; a fifth configuration to switch said sample circuit to sample and store said sampled common reset output signal when said transfer transistor is in said second triode region; and, a sixth configuration to switch said sample circuit to sample and store said sampled first sense-node reset signal when said transfer transistor is in said second OFF state.