Improved differential linearity performances of high speed Wilkinson-Recursive Subranging converters

Abstract

The paper presents a new method for Wilkinson Recursive Subranging (W-RS) conversion that ensures a high conversion rate and improved performance of differential and integral linearity. Starting from basic principles of W-RS conversion, which have been studied and presented by the author in other papers, we can reduce the conversion time from 2n+m steps, corresponding to Wilkinson conversion, to 2n + + 2m steps corresponding to the recursive conversion method which maintains performances of differential linearity specific to Wilkinson conversion. We have implemented a converter with a number of 32,000 conversion channels, for a medium conversion time of 2 MSPS with a 0.7% improved differential linearity by choosing for both steps an 8-bit conversion and taking into account the overlap of a bit for each step of the conversion used to perform digital connection. The new method presented in this paper is patented by the author.