Patent ID: 6809768
Filing Date: 2004-10-26
Classification: H04N

Abstract:
An active pixel sensor disposed on a semiconductor substrate comprising:a first photodiode having a first terminal coupled to a fixed potential and a second terminal, said first photodiode having a first size; a second photodiode having a first terminal coupled to a fixed potential and a second terminal, said second photodiode having a second size smaller than said first size; a first semiconductor reset switch having a first terminal coupled to said second terminal of said first photodiode and a second terminal coupled to a first reset potential that reverse biases said first photodiode; a second semiconductor reset switch having a first terminal coupled to said second terminal of said second photodiode and a second terminal coupled to a second reset potential that reverse biases said second photodiode; a first semiconductor source-follower amplifier having an input coupled to said second terminal of said first photodiode and an output; a second semiconductor source-follower amplifier having an input coupled to said second terminal of said second photodiode and an output coupled to the output of said first semiconductor source-follower amplifier; said first and second semiconductor reset switches each having a control element coupled to a control circuit for selectively activating said first and second semiconductor reset switches.