A 16nm configurable pass-gate bit-cell register file for quantifying the VMIN advantage of PFET versus NFET pass-gate bit cells

Abstract

A 16nm configurable pass-gate bit-cell register file allows a direct comparison of NFET versus PFET pass-gate bit cells for early technology evaluation. The configurable pass gate enables either a transmission-gate (TG), an NFET pass gate, or a PFET pass gate. From silicon test-chip measurement, the register file with PFET pass-gate bit cells achieves a 33% minimum supply voltage (VMIN) reduction in a 16nm FinFET technology and a 40% VMIN reduction in an enhanced 16nm FinFET technology as compared to a register file with NFET pass-gate bit cells. Test-chip measurements highlight the superior benefits of the PFET drive current relative to the NFET drive current at low voltages. The VMIN improvement with a PFET pass-gate bit cell represents a paradigm-shift from traditional CMOS circuit-design practices.