Body Bias Driven Design Synthesis for Optimum Performance per Area

Maurice Meijer and Jose Pineda de Gyvez
NXP Semiconductors


Worst-case design uses extreme process corner conditions which rarely occur. This costs additional power due to area over-dimensioning during synthesis. We present a new design strategy for digital CMOS IP that makes use of forward body biasing. Our approach renders consistently a better performance-per-area ratio by constraining circuit over-dimensioning without sacrificing circuit performance. Dynamic power is reduced depending upon the ratio of flip-flops to logic-gates, and data activity. On a set of benchmark circuits in 65nm LP-CMOS, we observed performance-per-area improvements up to 81%, area and leakage reductions up to 38%, and total power savings of up to 26% without performance penalties.