Patent ID: 7864229
Filing Date: 2011-01-04
Classification: H03M,H04N

Abstract:
1. An analog to digital converting device, comprising: a first correlated double sampling (CDS) circuit configured to generate a first sampling signal by performing CDS on an active pixel output signal output from an active pixel and to generate a first comparison signal by comparing the first sampling signal with a reference signal, the first CDS circuit being configured to generate the first sampling signal in response to a ramp signal and the active pixel output signal; a second CDS circuit configured to generate a second sampling signal by performing CDS on an OB pixel output signal output from an optical black (OB) pixel and to generate a second comparison signal by comparing the second sampling signal with the reference signal, the second CDS circuit being configured to generate the second sampling signal in response to a DC signal and the OB pixel output signal; and a reference signal generator configured to output the second sampling signal or a signal related to the DC signal as the reference signal in response to a switching signal, wherein the reference signal generator includes: