A low-power decibel-linear CMOS Automatic Gain Control

This paper presents an all CMOS decibel-linear Automatic Gain Control (AGC). This AGC achieves large dynamic range with low power consumption. By applying digital switches to change exponential approximation function, four dynamic ranges (62, 50, 33, 26 dB) are realized. This AGC is implemented in TSMC 0.18-μm CMOS RF process. Measurement results show that this AGC achieves 60 dB linear range with linearity error less than 1 dB. The whole circuit consumes 3.6 mA from 2-V supply.