Multi-Vth Level Conversion Circuits for Multi-VDD Systems

Employing multiple supply voltages (multi-V_DD) is attractive for reducing the power consumption without sacrificing the speed of an integrated circuit (IC). In order to transfer signals among the circuits operating at different voltage levels specialized voltage interface circuits are required. Two novel multi-threshold voltage (multi-V_th) level converters are proposed in this paper. The proposed level converters are compared with the previously published circuits for different values of the lower supply voltage. When the circuits are individually optimized for minimum power consumption in a 0.18mum CMOS technology, the proposed level converters offer significant power savings of up to 70% as compared to the previously published circuits. Alternatively, when the circuits are individually optimized for minimum propagation delay, speed is enhanced by up to 78% with the proposed circuits.