Characterization of mode transition timing overhead for net energy savings in low-noise MTCMOS circuits

Multi-threshold CMOS (MTCMOS) is commonly utilized for suppressing leakage currents in idle integrated circuits. The deactivation/reactivation energy consumption however degrades the effectiveness of MTCMOS technique for providing significant savings in total energy consumption in CMOS integrated circuits. The mode transition energy overheads of various recently published low-noise ground-gated MTCMOS circuits are characterized in this paper. With a digital triple-phase sleep signal slew rate modulated MTCMOS circuit, the overall mode transition energy consumption is reduced by up to 45.31% as compared to the other MTCMOS circuits that are evaluated in this paper in a UMC 80nm CMOS technology. Furthermore, the digital triple-phase MTCMOS circuit shortens the mode transition timing overhead by up to 65.26% as compared with the other MTCMOS circuits that are evaluated in this paper.