Patent ID: 7265706
Filing Date: 2007-09-04
Classification: H03M,H04N

Abstract:
1. A method of operating an image sensor, said method comprising: holding a first analog input signal at the output of a digital-to-analog converter, said first analog input signal including a floating diffusion reset voltage; applying said first analog input signal from the output of said digital-to-analog converter to an operational amplifier having a first input line and a second input line, the floating diffusion reset voltage being applied to the second input line to generate an operational amplifier output; applying the operational amplifier output to a first side of a sample and hold capacitor; applying a second analog input signal to a second side of the sample and hold capacitor to generate an adjusted input voltage across said sample and hold capacitor, wherein the adjusted input voltage is the difference between the voltage at the first side of said sample and hold capacitor and the voltage at the second side of said sample and hold capacitor; and applying the adjusted input voltage to the first input line of said operational amplifier.