Patent ID: 7199349

Claim:
A method of obtaining a signal from a pixel cell comprising: generating charges with a photodetector during an integration period; resetting a charge storage node that receives charges generated by said photodetector to a reset level; resetting a capacitive transimpedance amplifier associated with the pixel cell; biasing the capacitive transimpedance amplifier with a first voltage level to place the amplifier in a high power operating mode; with the storage node at the reset level, reading and sampling a first output signal from the capacitive transimpedance amplifier having an input coupled to said storage node; biasing the capacitive transimpedance amplifier with a second voltage level to place the amplifier in a low power operating mode; receiving charges at said charge storage node generated by said photodetector during the integration period; biasing the capacitive transimpedance amplifier with the first voltage level to place the amplifier in the high power operating mode; and reading and sampling a second output signal from said capacitive transimpedance amplifier after said integration period.