Circuit prospects of DGFET: Variable gain differential amplifier an a schmitt trigger with adjustable hysteresis

Double Gate(DG)FET is one of the most promising technologies for sub-50 nm transistor design. Various attempts have been made to exploit this newly emerging technology in electronic circuits [1, 2]. Threshold voltage of a double gate MOSFET can be varied by varying the bias on the back gate [1]. In this paper we propose a variable gain differential amplifier with current mirror load utilizing this property. Also it is shown that the saturation voltage of the differential amplifier varies with the varying back gate bias of the DGFETs. The variable gain differential amplifier has been used to propose a variable hysteresis voltage schmitt trigger, the hysteresis voltage of which can be varied without the help of external circuitry and only by varying backgate bias of the DGFETs. The nature of variation of hysteresis voltage with varying backgate bias of the transistors is also investigated.