Improved Delta Sigma Analog to Digital Converter

Abstract

This paper describes an analog-to-digital converter which combines multiple delta-sigma modulators in parallel so that time over sampling may be reduced or even eliminated. By doubling the number of Lth-order delta-sigma modulators, the resolution of this architecture is increased by approximately L bits. Thus, the resolution obtained by combining M delta- sigma modulators in parallel with no over sampling is similar to operating the same modulator with an over sampling rate of M. A parallel delta-sigma A/D converter implementation composed of two, four, and eight second-order delta-sigma modulators is described that does not require over sampling.