Self adaptive body biasing scheme for leakage power reduction in nanoscale CMOS circuit

Abstract

This paper presents techniques to determine the optimal reverse body bias (RBB) voltage to minimize leakage currents in modern nanoscale CMOS technology. The proposed self-adaptive RBB system finds the optimum reverse body bias voltage for minimal leakage power adaptively by comparing subthreshold leakage current (ISUBTH), gate tunneling leakage (IGATE), and band-to-band tunneling leakage currents (IBTBT) in standby mode. The proposed circuit has been designed and tested using 65nm bulk CMOS technology at 25oC under a supply voltage of less than 1V. The optimal RBB was achieved at -0.372V with 1.2% error in the test case of the paper, and the simulation result shows that it is possible to reduce the total leakage current significantly as much as 86% of the total leakage using the proposed circuit techniques.