Design of AGC amplifier for CMOS Image Sensor

Abstract

This paper designed an automatic gain control(AGC) amplifier for CMOS Image Sensor. The AGC amplifier adopts translinear variable gain amplifier (VGA) to realize a good linearity. It detects valley to present the strength of signal, and uses a succinct adjustment circuit to control the gain of VGA. A bandgap reference not needing start-up circuit was designed for the whole system. Simulated in SMIC 0.35um CMOS, it can compressed the dynamic range of 100kHz signal from 55.32dB to 7.36dB.