Patent ID: 8233070
Filing Date: 2012-07-31
Classification: H01L,H04N

Abstract:
1. A pixel sensor cell circuit comprising: a photodiode coupled in series with a first source/drain region of a transfer gate transistor; a floating diffusion coupled in series with a second source/drain region of the transfer gate transistor; a column circuit output coupled to the floating diffusion through a gate of a source follower transistor connected to the floating diffusion, the source follower transistor coupled in series with a row select transistor whose source/drain region provides the column circuit output; and a column circuit connected to the column circuit output, the column circuit including a first set of two pass gate transistors and a second set of two pass gate transistors, each pass gate transistor of said first set and second set having a first source/drain region connected in parallel to the column circuit output, each of said two pass gate transistors of each respective said first and second set further having a second source/drain region connected in series to a separate data storage capacitor, wherein said first set of two pass gate transistors is configured for a correlated double sampling mode to obtain a respective first reference charge and a first signal charge from the floating diffusion with the transfer gate transistor off; and said second set of two pass gate transistors is configured for an uncorrelated double sampling mode to obtain a respective second reference charge and a second signal charge different from the first signal charge from the floating diffusion with the transfer gate transistor on.