nMOS Reversible Energy Recovery Logic for Ultra-Low-Energy Applications

Abstract

We propose a new fully reversible adiabatic logic, nMOS reversible energy recovery logic (nRERL), which uses nMOS transistors only and a simpler 6-phase clocked power. Its area overhead and energy consumption are smaller, compared with the other fully adiabatic logics. We employed bootstrapped nMOS switches to simplify the nRERL circuits. With the simulation results for a full adder, we confirmed that the nRERL circuit consumed substantially less energy than the other adiabatic logic circuits at low-speed operation. We evaluated a test chip implemented with 0.8- m CMOS technology, which included a chain of nRERL inverters integrated with a clocked power generator. The nRERL inverter chain of 2400 stages consumed the minimum energy at dd = 3 5 V at 55 kHz, where the adiabatic and leakage losses are about equal, which is only 4.50% of the dissipated energy of its corresponding CMOS circuit at dd = 09 V. In conclusion, nRERL is more suitable than the other adiabatic logic circuits for the applications that do not require high performance but low energy consumption.