An 0.08e–·pJ/Step 14-bit Gain-Adaptive Single-Slope Column ADC with Enhanced HDR Function for High-Quality Imagers

Abstract

We developed a high-speed, power-efficient single-slope column ADC. The ADC detects and attenuates the bright signals before conversion. A 7.1 Mpixel stacked prototype CMOS image sensor implementing the new ADC attains 14-bit, 224 fps with good characteristics. The ADC also works efficiently with pixel dual-conversion gain readout, achieving a dynamic range of 91 dB.