Noise-cancelling image sensors

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.