A low distortion and fast settling automatic gain control amplifier in CMOS technology

This paper presents an automatic gain control (AGC) circuit with the improvement of the harmonic distortion and tracking time in CMOS technology. A configuration, which is comprised of V-V converters and a corner tracker, is proposed to extend the linear-in-dB range of the variable gain amplifier (VGA) and to increase the tolerance of the circuit to process corner variation. A new comparator technique is introduced to speed up the tracking time of the AGC circuit and to reduce the acquisition time of the system. The AGC consumes 8 mA current and has a 100 MHz 3-dB bandwidth in 0.35 /spl mu/m CMOS technology, which is suitable to the use in IF amplifier in modern wireless communication systems.