CMOS active pixel sensor with on-chip successive approximation analog-to-digital converter

Abstract

The first CMOS active pixel sensor (APS) with onchip column-parallel successive-approximation analog-to-digital converter (ADC) is reported. A 64 × 64 element CMOS APS implemented in a 1.2-μm n-well single-poly double-metal process with 24-μm pixel pitch is integrated with a 64 × 1 array of column parallel successive approximation 8-b ADC's. Good image quality was observed. The capacitively-coupled ADC's dissipate approximately 1 μW-s/ksample and occupy 0.05 mm2 of chip area. © 1997 IEEE.