An 8 b CMOS vector A/D converter

A vector A/D (analog-to-digital) converter is described. The IC stores a codebook of vectors on-chip, accepts a 16-element analog vector at the input, and calculates the Euclidean distance between the input and all codevectors (referred to as global search) to produce an 8-b code indexing the codevector closest to the input prompt. At 5-MHz clock rate, the chip dissipates less than 50 mW quantizing a new 16-element analog vector every 10 clock periods, which means that it can encode an entire 512*512 pixel gray-scale image in 4*4 blocks at 30-Hz frame rate.<
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