Mode transition timing and energy overhead analysis in noise-aware 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 the MTCMOS technique for providing significant savings in total energy consumption in CMOS integrated circuits. The sources of mode transition energy consumption in noise-aware MTCMOS circuits are investigated in this paper. The mode transition energy overheads of various recently published low-noise ground-gated MTCMOS circuits are characterized. 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 80 nm CMOS technology. Furthermore, digital triple-phase sleep signal slew rate modulation shortens the mode transition timing overhead by up to 65.26% as compared with the other MTCMOS noise suppression techniques that are evaluated in this paper.