A Low-Voltage Low-Power Wide-Range CMOS Variable Gain Amplifier

caroline11

Abstract—In this paper, a compact low-power (LP) low-voltage (LV) metal–oxide–semiconductor-only (MOS-only) variable gain amplifier (VGA) is introduced. This amplifier based on complementary MOS (CMOS) transistors operating in strong inversion is composed of a pseudo-exponential current-to-voltage converter, Analog multiplier, and output stage. The gain of the amplifier is controlled exponentially by a novel wide-range pseudoexponential current-to-voltage converter implemented with two back-to-back connected current mirrors exhibiting superb exponential characteristic. Also, a new LV/LP composite transistor is introduced to increase the input dynamic range of the multiplier. The amplifier is fabricated using a 2-m MOSIS n-well process, and its simulation and measurement results are shown in detail.