Soft-FET: Phase transition material assisted Soft switching F ield E ffect T ransistor for supply voltage droop mitigation

Abstract

Phase Transition Material (PTM) assisted novel soft switching transistor architecture named "Soft-FET" is proposed for supply voltage droop mitigation. By utilizing the abrupt phase transition mechanism in PTMs, the proposed Soft-FET achieves soft switching of the gate input of a logic gate resulting in reduced peak switching current as well as steep current variations (di/dt). In addition, the Soft-FET incurs lower delay penalty across a wide voltage range compared to various baseline Complementary Metal Oxide Semiconductor (CMOS) logic gate variants for the same peak current. We perform a detailed PTM parameter optimization for optimum Soft-FET performance. Soft-FETs when used as power gates achieve ~20mV lower supply droop and when used as an I/O buffer achieves 46% lower ground bounce with 8.8% improved energy efficiency.