Mark Vesterbacka, K. Ola Andersson, Niklas U. Andersson, J. Jacob Wikner
USING DIFFERENT WEIGHTS IN DACs
In this paper we discuss some properties of different codes with their respective sets of weights to be used in digital-to-analog converters (DACs). The thermometer (unratioed) code is widely used instead of a binary code in the most significant bits of a segmented DAC to reduce errors due to weight and timing mismatch. The binary and thermometer codes are two extremes, where the first offers a small digital hardware cost and the latter a large cost. We have investigated some of the properties of these codes and codes with properties in-between; such as linear, polynomial, and segmented codes. Some new ideas and results on using different sets of weights and how to generate them are presented. We present simulation results for some low-order polynomial codes.