Low voltage fully differential CMOS voltage mode digitally controlled variable gain amplifier

摘要

In this paper, a voltage mode variable gain amplifier (VGA) is presented. A fully differential implementation is used to suppress the common mode noise and increase the dynamic range. The gain of the proposed VGA can be digitally controlled from 0 to 53 dB, with a 1 dB resolution. The gain control is performed in two stages; coarse control with a 6 dB resolution and fine control with a 1 dB resolution. Simulation shows that the bandwidth is about 15 MHz at the maximum gain (53 dB). The differential output third intercept point (OIP3) is 4 V.