Answer 5—If the dither is added at just one end of the A/D input range, the actual dither amount will vary with the signal level. Signals near the other reference level will have little or no dither. The correct way to apply the dither is to couple it simultaneously into both the upper and lower references of the A/D converter. Obviously, this requires a converter that makes both reference levels available externally.

Contributor: Dave Tweed

Published August 2003