A low-voltage low-power wide-range CMOS variable gain amplifier

摘要

In this paper, a compact low-power (LP) low-voltage (LV)nmetal-oxide-semiconductor-only (MOS-only) variable gain amplifier (VCA)nis introduced. This amplifier based on complementary MOS (CMOS)ntransistors operating in strong inversion is composed of anpseudo-exponential current-to-voltage converter, analog multiplier, andnoutput stage. The gain of the amplifier is controlled exponentially by annovel wide-range pseudo-exponential current-to-voltage converternimplemented with two back-to-back connected current mirrors exhibitingnsuperb exponential characteristic. Also, a new LV/LP compositentransistor is introduced to increase the input dynamic range of thenmultiplier. The amplifier is fabricated using a 2-Μm MOSIS n-wellnprocess, and its simulation and measurement results are shown in detail