A Novel Low Area Overhead Direct Adaptive Body Bias (D-ABB) Circuit for Die-to-Die and Within-Die Variations Compensation

A direct adaptive body bias (D-ABB) circuit is proposed in this paper. The D-ABB is used to compensate for die-to-die (D2D) and within-die (WID) parameter variations, and accordingly, improves the circuit yield regarding the speed, the dynamic power, and the leakage power. The D-ABB circuit consists of threshold voltage estimation circuits and direct control of the body bias performed by on-chip direct controller circuits. Circuit level simulation results of a circuit block case study, extracted from a real microprocessor critical path, referring to an industrial hardware-calibrated 65-nm CMOS technology transistor model, are presented. These results show that the proposed D-ABB reduces the standard deviations of the frequency, the dynamic power, and the leakage power by factors of 5.5×, 6.4×, and 4.5×, respectively, when both D2D and WID variations are considered. In addition, in the presented case study, initial total yields of 16.8% and 13% are improved to 100% and 91.4%, respectively. The proposed D-ABB circuit exhibits lower area overhead compared to the other ABB circuits reported in the literature.