Wideband Distortion Contribution Analysis of analog circuits with differential signalling

Abstract

Distortion Contribution Analysis (DCA) is a simulation-based analysis in which the total output distortion generated by an analog electronic circuit is split into the contributions of each of its sub-circuits. Earlier work has shown that combining the Best Linear Approximation (BLA) with a classic noise analysis yields a DCA which uses a wideband excitation signal without requiring knowledge about the underlying technology. In this paper, the BLA-based DCA is augmented to be able to cope with circuits that use differential signalling. Transforming the Sparameters of the sub-circuits in the DCA into a representation that works on the differential and common-mode signals leads to distortion contributions which are easy to interpret when differential signals are present in the circuit. Additionally, an improved test is introduced to indicate the accuracy of the DCA.