Cell-based variable-gain amplifiers with accurate dB-linear characteristic in 0.18 µm CMOS technology
Boon, Chirn Chye
Date of Issue2014
School of Electrical and Electronic Engineering
A simple and robust “cell-based” method is presented for the design of variable-gain amplifiers (VGAs). The proposed unit cell utilizes a unique gain compensation method and achieves accurate dB-linear characteristic across a wide tuning range with low power consumption and wide bandwidth. Several such highly dB-linear unit cells can be cascaded to provide the required gain range for a VGA. To prove the concept, single-cell, 5-cell, 10-cell and 15-cell reconfigurable VGAs were fabricated in a standard 0.18 μm CMOS technology. The measurement results show that the 10-cell VGA achieves a gain range of 38.6 dB with less than 0.19 dB gain error. The 15-cell VGA can either be used as reconfigurable VGA for analog control voltage or tunable PGA for digital control stream, with the flexibility of scaling gain range, gain error/step and power consumption. For the VGA at highest gain setting, it consumes 1.12 mW and achieves a gain range of 56 dB, gain error less than 0.3 dB.
DRNTU::Engineering::Computer science and engineering::Hardware::Integrated circuits
IEEE journal of solid-state circuits
© 2014 IEEE. This is the author created version of a work that has been peer reviewed and accepted for publication by IEEE Journal of Solid-State Circuits, IEEE. It incorporates referee’s comments but changes resulting from the publishing process, such as copyediting, structural formatting, may not be reflected in this document. The published version is available at: [Article URL/DOI: http://dx.doi.org/10.1109/JSSC.2014.2368132].