ADC for cancelling column fixed pattern noise and CMOS image sensor using it

摘要

This invention relates to the ADC for removing fixed pattern noise, the input voltage (V _IN ) and compared to a constant increase ramp (Ramp) input has a slope with time, and a comparison unit for comparing the results output to the sync shift output; Sync shift unit for shifting the block sync signal on the basis of C-FPN C-FPN removal information received from the memory for the removal and the comparison result of the comparison section; n-bit counter which outputs a memory for the n-bit digital counter output value of the n-bit memory or C-FPN elimination; n-bit memory for storing the sync signal by using the shifted digital counter output value of the n-bit counter; And a digital counter output value of the n-bit counter corresponding to the reference voltage comprises a C-FPN removal for a memory block to provide the sync shift unit, characterized in that the sync signal is a signal used to determine the output value of the n-bit digital counter counter with and, by solving the transformation characteristic difference between the column ADC, may implement the enhanced image can be removed from the C-FPN properties of CIS. ;