HIGH-SPEED 8-BIT A-D CONVERTER BASED ON A GRAY-CODE MULTIPLE FOLDING CIRCUIT

An A/D converter is described using a parallel structure to synthesize the multiple folding transfer characteristic for the Gray code. The number of comparators needed equals that of a purely sequential design. The performance is demonstrated by an 8 bit converter for video application, as well as a nonlinear version for PCM speech encoding. In both designs a 4 bit multiple folding circuit is followed by a 4 bit parallel block. Copyright © 1979 by The Institute Of Electrical And Electronics Engineers, Inc.