Bidirectional Single-Supply Level Shifter with Wide Voltage Range for Efficient Power Management

Abstract

Level shifter circuits are used to interface multiple voltage islands in many modern ICs or Systems-on-Chip (SoCs). Single-supply level shifters are being used to reduce the power routing resources and minimize the routing congestion at the chip level. A single-supply bidirectional level shifter aimed at low voltage which offers a wide voltage range (SS-WVRLS) is designed using standard commercial 90nm CMOS process. The proposed level shifter uses analog and digital circuit techniques to provide full voltage shifting range for any combination of supply voltages (VDDIN = VDD,VDDIN <; VDD or VDDIN >; VDD) in any step size (paper shows 25mv step) with no requirement for special low-Vτ or high-Vτ devices, thus reducing the process cost. Post layout SPICE simulation comparison results show that proposed circuit is functional for full core supply voltage range (0.6V - 1.32V) compared to other published level shifters. The circuit was tested for robustness under process mismatch conditions by 1000 point global and local Monte Carlo simulations.