An Optimal Supply Voltage Determiner Circuit for Minimum Energy Operations

We have developed a circuit for determining an optimal supply voltage, VOPT for which energy consumption in circuit operations will be minimized in devices suffering from high-leakage. This VOPT is determined on the basis of a trade-off between power consumption and delay time. Experimental results with a 90-nm CMOS device indicate that the proposed circuit successfully determines VOPT within 3% of actual minimum energy consumption. VOPT operations with power gating at 40 MHz, and where VDD=0.67 V, results in an energy reduction of 52.8% over that achieved with DVFS alone at 5 MHz (1/20 of maximum operational frequency).