Patent ID: 11172157

Abstract:
Techniques are described for digital conversion of pixel signals in a CMOS image sensor (CIS). The CIS includes column-parallel analog-to-digital converters (ADCs), each having a programmable gain amplifier (PGA) supporting N gain settings. Each ADC can execute, for each gain setting (Gn) of the N gain settings, a respective reset phase conversion to obtain a respective baseline offset (BOn) associated with the Gn. A pre-decision value can be determined as a function of a pixel signal, the pre-decision value corresponding to a selected one of the gain settings (Gs). The pixel signal can be converted by using the pre-decision value to set a gain of the PGA to the Gs and obtaining a signal offset (SO). A digital pixel output can be computed for the pixel signal as a function of the SO and the BOs, wherein the BOs is the BOn corresponding to the Gs.