Patent ID: 6424375
Filing Date: 2002-07-23
Classification: H04N

Abstract:
A method of providing low noise readout from a pixel device in an image sensor, wherein the image sensor includes a reset circuit having a reset control loop for controlling the reset of the pixel device, the reset control loop including a compare module and a switch, the compare module having a first input for receiving a reset signal and a second input for receiving a feedback signal from a readout node, the readout node being coupled to outputs of the switch and pixel device, the readout node having a readout signal thereon, respectively, the method comprising the steps of:(a) comparing the reset signal with the feedback signal; (b) turning the switch on and off in response to a difference detected between the reset signal and the feedback signal; and (c) controlling the reset control loop with capacitance in the reset control loop in response to the switch turning off, wherein the feedback signal reduces noise at the readout node.