Abstract
A CMOS cascadable variable gain amplifier (VGA) with exponential gain control characteristic is presented. The pseudo-exponential gain control function is realized by a source-coupled pair with diode-connected loads. It is suitable for low supply and high speed applications. Using 0.5 μm CMOS technology, experimental results show the bandwidth of the proposed amplifier is larger than 150 MHz with a gain control range of 15 dB. The power consumption is 12.5 mW from a 3.3-V power supply.