Analog circuit design based on independently driven double gate MOSfet

Abstract

This paper reviews two basic analog circuits that employ new capabilities brought about by independently driven double gate CMOS transistors (IDGMOS). The subject of the first review is a 1 V supply voltage follower that uses IDGMOS to increase the input range up to the supply voltage and to enhance the biasing circuit of the follower. The second looks at a new general method to make fully balanced differential amplifiers (FBAs) with compact common-mode feed back. IDGMOS FBAs perform complete transistor reuse without using any extra device to execute the feed-back amplifier functions, i.e. error evaluation and amplification. An application of this is illustrated with the simulation of a simple 1-stage differential amplifier with 38 dB gain and a 90.3 degree phase margin. The complete feed back loop includes the aforementioned voltage follower. The common-mode open loop gain is only about 21 dB but the common-mode reference voltage range, within 10% relative error, remains between 0.3 V and 0.9 V.