Open AccessCDS circuit with 0 to 18 dB, 9‐bit VGA functionality
Author(s) -
Zhuang Haoyu,
Zhu Zhangming,
Yang Yintang,
Liu Lianxi
Publication year - 2014
Publication title -
electronics letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.375
H-Index - 146
eISSN - 1350-911X
pISSN - 0013-5194
DOI - 10.1049/el.2013.2133
Subject(s) - video graphics array , variable gain amplifier , linearity , electronic engineering , computer science , noise (video) , engineering , amplifier , operational amplifier , cmos , image (mathematics) , artificial intelligence
For processing charge coupled device (CCD) signals, a correlated double sampling (CDS) circuit must be used to eliminate noise. Usually, the amplitude of the CCD signals is uncertain, either too small or too large, hence a variable‐gain amplifier (VGA) is also needed to amplify the CCD signals. Traditionally, the CDS and the VGA are separated, each of which consumes much energy and large area. If only the CDS and the VGA would be combined together, much energy and area could be saved. Hence, a CDS with VGA functionality is proposed to achieve this goal. Besides, the VGA functionality provides a gain range of 0–18 dB, programmable with a 9 bit resolution, which is far better than the traditional ones. Also, the VGA gain curve follows a linear‐in‐dB characteristic, hence the VGA functionality has rather good linearity. Finally, the VGA gain curve demonstrates the good performance of the VGA functionality.