Mapping from phase to sine-amplitude in direct digital frequency synthesizers using parabolic approximation

Abstract

This paper describes a new approach in sine-amplitude approximation for sine-output direct digital frequency synthesizers, which provides an initial guess much closer to the target sine amplitude than previous approximations. Another important advantage of the proposed idea is that it can be simply implemented using full-digital circuitry. Gate- and transistor-level simulations demonstrate the feasibility of the idea, and the simulation results are in complete agreement with the experimental results for the implemented test architecture.