Chip Estimate: Cambridge Analog Technologies (CAT) has developed Precision Ultra Micro-power Amplification (PUMA) technology-based ADC IP applicable to image sensor applications. The company implements MIT-developed low-power switched capacitor techniques. While most switched cap circuits rely on op-amps, CAT uses zero-cross detectors (ZCD) to switch on/off capacitor charging sources:
The ZCD-based circuits are said to consume one to two orders of magnitude less power than op-amp for the same settling time and accuracy. Now power numbers are given in the article, while white papers published on the company's site suggest much smaller savings.