A Cross-Coupled Pair Regeneration Based dB-Linear Programable Gain Amplifier with THD Enhancement

Abstract

This paper reports a cross-coupled pair regeneration based programmable gain amplifier (CCPR-PGA) with an improved total harmonic distortion (THD) performance. By utilizing the ping-pong technique, two identical conventional CCPR-PGAs are operating alternatively. These two CCPR-PGAs connect to the output of the overall PGA only at their hold state, as a result, the ripples generated during the processes of reset, sample and regeneration are effectively suppressed. Simulated in 28-nm CMOS technology, the proposed PGA achieves a gain range of 45.4 dB with a gain error of ± 0.3 dB. The bandwidth of the proposed PGA reaches 40 MHz with a clock frequency of 100 MHz. Moreover, the THD performance is improved by 25.8 dB at 1 MHz and 17.6 dB at 10 MHz when compared to the conventional structure. The overall PGA consumes 460 µA current from a supply voltage of 0.9 V.