Low gain error, linear-in-dB variable gain amplifier with programmable gain range and gain steps

This paper presents a linear-in-dB variable gain amplifier (VGA) with programmable gain range and gain step, and low gain error. A 4-bit digitally controlled look-up-table and a “pre-calibration” method yield a maximum gain range of 47 dB with 10 programmable gain step options, while most gain errors are kept below ±0.3dB. The proposed VGA occupies an active area of 0.011mm2 in a standard 0.18μm CMOS process and consumes 1.42 mW from a 1.8-V supply.