An 8 b CMOS vector A/D converter

Abstract

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.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>