DT Modeling of Clock Phase Noise Effects in LP CT Delta-Sigma ADCs with RZ Feedback

Summary, in English

The performance of continuous-time (CT) Delta Sigma modulators is limited by their sensitivity to clock phase noise (PN). The clock PN-induced in-band noise (IBN) is dependent on the magnitude and frequency of both the desired in-band signals and the out-of-band signals, as well as the shape of the clock PN spectrum. This brief presents a discrete-time (DT) model of the dominant clock PN-induced errors. It enables fast and accurate simulations of the clock PN effects with arbitrary input signals, PN spectra, and noise-transfer functions. The model has been verified by CT simulations and measurements on a second-order low-pass CT Delta Sigma modulator with return-to-zero feedback. The flexibility and usefulness of the DT model are demonstrated, and the two dominant clock PN effects are compared by means of simulations with orthogonal frequency-division multiplexing input signals and various PN specifications.

• Author: Martin Andersson; Lars Sundström
• Department/s: Department of Electrical and Information Technology; Departments at LTH
• Publishing year: 2009
• Language: English
• Pages: 530-534
• Publication/Series: IEEE Transactions on Circuits and Systems II: Express Briefs
• Volume: 56
• Issue: 7
• Links: http://dx.doi.org/10.1109/TCSII.2009.2020950
• Document type: Journal article
• Publisher: IEEE - Institute of Electrical and Electronics Engineers Inc.
• Topic: Electrical Engineering, Electronic Engineering, Information Engineering
• Status: Published
• Research group: Analog RF; Data converters & RF
• ISBN/ISSN/Other: ISSN: 1549-7747