Wednesday, December 01, 2010

CAT PUMA Pursues Image Sensor Applications

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.

4 comments:

  1. This kind of power savings will increase the injection of spikes into the supply/ground, so it will probably generate quite some artifacts in the image. If u really want to save current without spikes use a hybrid/soft version (sure at the cost of complexity).

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  2. but the precision is related to the ZCD's speed, better precision should use higher speed and more consumption. What is the real advantage of this? You can also use a dynamically biased OP-AMP.

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  3. very impressive work !!!!

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  4. @ "What is the real advantage of this?"

    If we just look on the numbers in the CAT's papers, they are not bad at all. Indeed, there guys present 10enob/100Msps ADC having 6.2mW power consumption and 12b-10enob/50Msps ADC consuming 4.5mW power. This is quite in-line with the best alternatives.

    If comparing with column-parallel approach, one needs to add a power of analog demux and PGA to make a fair comparison.

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