A low-distortion multi-bit sigma–delta ADC with mismatch-shaping DACs for WLAN applications. Issue 1 (January 2015)

• Record Type: Journal Article
• Authors: Li, Di; Yang, Yin-Tang; Shi, Zuo-Chen; Liu, Yang
• Is Part Of: Microelectronics journal. Volume 46:Issue 1(2015)
• Page Start: 52
• Page End: 58
• Publication Date: 2015-01
• Subjects: Microelectronics -- Periodicals; Microélectronique -- Périodiques; Microelectronics; Electronic journals; Journals - contents and abstracts; Periodicals; 621.3805
• DOI: 10.1016/j.mejo.2014.10.004
• Languages: English
• ISSNs: 0959-8324

Abstract

<abstract abstract-type="author" id="ab0005"> <title id="sect0005">Abstract</title> <sec> <p id="sp0055">A low-distortion feed-forward MASH2_4b-2_4b sigma–delta analog-to-digital converter (ADC) for wireless local area network (WLAN) applications was presented. The converter exhibits improved performances than the ADCs which have been presented to date by adding a feedback factor in the second stage and employing a 2nd-order noise-shaping dynamic element matching (DEM) scheme. The feedback factor induces a zero in the noise transfer function (NTF) and therefore improves the in-band signal to noise and distortion ratio (SNDR) of the modulator. The mismatch-shaping DEM was introduced and applied to the 4-bit DACs in this paper to improve the resolution and linearity of the ADC. Fabricated in a 0.18 μm CMOS process with single 1.8 V supply voltage, the converter achieves a peak SNDR of 85.4 dB over a 10 MHz bandwidth which implies an effective number of bits (ENOB) of 13.90-bit. The spurious free dynamic range (SFDR) is –94 dB for a 1.25 MHz@–6dBFS input signal at 160 MHz sampling frequency. The occupied area is 0.44 mm² and dissipation power 23.4 mW.</p> </sec> </abstract>