Just like the old song, the road of data conversion is long with many a winding turn. As to where it leads … Well, for high performance architectures, the choice of data converter comprises three main categories: successive approximation register (SAR); sigma delta (SD); and pipeline.
Each represents a different trade off between speed, resolution, power consumption and cost. Pipeline converters keep the speed freaks happy, whereas in direct contrast, delta sigma converters offer slow, steady and precise measurements and are therefore suitable for high resolution applications. SAR, meanwhile, is a proverbial ‘Jack of all trades’, straddling the middle ground between pipeline and delta sigma converters in terms of speed and accuracy.
However, there’s now a revelation in data conversion – continuous time sigma delta (CTSD). Major process changes have helped to put this technology at the forefront of industry applications like medical imaging.
CTSD technology has been the subject of university and industry research for more than 15 years but, with the launch of its first eight channel, 12bit, 50Msample/s CTSD a/d converter, National Semiconductor claims to be the first manufacturer to successfully transition CTSD technology from the research lab to the production line.
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