CDS circuit with 0 to 18 dB, 9-bit VGA functionality

• Published in: Electronics letters Vol. 50; no. 3; pp. 158 - 159
• Main Authors: Zhuang, Haoyu, Zhu, Zhangming, Yang, Yintang, Liu, Lianxi
• Format: Journal Article
• Language: English
• Published: Stevenage The Institution of Engineering and Technology 30.01.2014; Institution of Engineering and Technology; John Wiley & Sons, Inc
• Subjects: Amplification; amplifiers; analogue‐digital conversion; Applied sciences; Cadmium sulfides; CCD signal amplitude; CCD signal processing; CDS circuit; charge coupled device signal processing; Charge coupled devices; charge‐coupled device circuits; Circuit properties; Circuits; Circuits and systems; correlated double sampling circuit; Electric, optical and optoelectronic circuits; Electronic circuits; Electronics; Energy consumption; Exact sciences and technology; Gain; gain 0 dB to 18 dB; Imaging devices; integrated circuit noise; noise elimination; Noise levels; Sampling; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; signal conditioning circuits; Signal convertors; variable‐gain amplifier; VGA; word length 9 bit; CCD signal amplitude; integrated circuit noise; gain 0 dB to 18 dB; noise elimination; correlated double sampling circuit; CDS circuit; charge-coupled device circuits; signal conditioning circuits; analogue-digital conversion; VGA; charge coupled device signal processing; word length 9 bit; variable-gain amplifier; amplifiers; CCD signal processing; Charge coupled device; Uncertain system; Image sensor; Noise reduction; Linearity; Variable gain amplifier
• ISSN: 0013-5194; 1350-911X; 1350-911X
• DOI: 10.1049/el.2013.2133

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.