Low-power 42 dB-linear single-stage digitally-controlled variable gain amplifier

Abstract

A compact digitally-controlled single-stage variable gain amplifier (VGA) is introduced, which doubles the dB-linear range through the reconfiguration, saves power by 50% while maintaining the same linearity performance compared to those of the previous design. Implemented in 0.18 mu m CMOS technology, the 5-bit digitally-controlled VGA achieves dB-linear gain range of 42 dB ( 221 to 21 dB) with gain error less than +/- 0.55 dB, bandwidth of 84 MHz at maximum gain of 21 dB and maximum IIP3 of 14 dBm while consuming only 760 mu A from a 1.8 V supply.