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A large dynamic‐range, high dB‐linearity VGA using switch arrays and second‐order mismatch‐shaping DEM technique
Author(s) -
Li Di,
Yang Yintang,
Shi Zuochen,
Jing Zhan
Publication year - 2016
Publication title -
international journal of circuit theory and applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.364
H-Index - 52
eISSN - 1097-007X
pISSN - 0098-9886
DOI - 10.1002/cta.2101
Subject(s) - video graphics array , linearity , variable gain amplifier , cascade , electronic engineering , dynamic range , amplifier , cmos , voltage , wide dynamic range , converters , high dynamic range , computer science , electrical engineering , engineering , operational amplifier , chemical engineering
Summary A new large dynamic‐range variable gain amplifier (VGA) with improved dB linearity is presented. The traditional cascade VGA has the disadvantages of gain mismatch between sub‐stages and difficulty of employing mismatch cancelation or suppression algorithms. In this paper, switch arrays were used to make the sub‐stages or called gain cells in the coarse‐tuning stage (CTS) work independently and therefore prevent the integral operation of the gain errors. Then, a second‐order mismatch‐shaping DEM was applied conveniently to the CTS and shown to be a useful design technique in improving the dB‐linearity performance. The cascade VGA and its second‐order mismatch‐shaping DEM had been integrated in a 2.4‐GHz receiver chip which was fabricated in a 0.18‐µm CMOS technology with a supply voltage of 1.8 V. Measurement results showed that the gain errors were significantly reduced with second‐order mismatch‐shaping DEM with respect to the traditionally thermometric decoding over a temperature range of [−40, 80] °C. Copyright © 2015 John Wiley & Sons, Ltd.