A switched gain cell parametric amplifier

This paper describes a discrete-time parametric amplifier based on the recently introduced `switched gain cell technique´. The proposed amplifier is realized by combining an ordinary subthreshold transconductor, a capacitor and a few MOS switches. By splitting the circuit operation into two phases for sampling and amplification, the internal parameter of the transconductor (bias current in this case) can be varied during the transition. This leads us to achieve a programmable linear current amplification in discrete-time domain. Effects of some circuit´s non-idealities, i.e. noise and distortion, are analyzed and discussed. Simulation results using AMS 0.18-μm CMOS process parameters are also given.