Low power ROM Employing Dynamic Threshold-Voltage MOSFET (DTMOS) Technique

Abstract

This paper examines the performance of two 128-bit ROM circuits, implemented on Silterra 0.18 u CMOS process. The first circuit is built using standard NMOS transistors, runs on 0.9 V supply voltage, has gate voltage of 0.45 V and consumes 102.07 muW power. The second circuit is designed partly using Dynamic Threshold-Voltage MOSFET (DTMOS) transistors with the aim to minimize power consumption. It runs on 0.7 V supply and has gate voltage of 0.35 V. The DTMOS approach is implemented on the 128-bit ROM core and in the pull up circuit of the column decoder. The latter ROM circuitpsilas power consumption is 38.93 muW, 61.86% less than the former, at the expenses of larger die area due to the usage of deep n-well process. The standard and DTMOST circuits have the die areas of 0.139 mum2 and 0.235 mum2, respectively.