A limited-contention cross-coupled level shifter for energy-efficient subthreshold-to-superthreshold voltage conversion

The subthreshold level shifter is an indispensable circuit for ultra-low voltage systems to communicate with different power domains. In this paper, we present a limited-contention level shifter using non-ratioed cross-coupled structure instead of ratioed one. Experimental results show that the proposed circuit can robustly convert subthreshold input up to superthreshold output. About 55% static power reduction is achieved without sacrifing performance when compared with the cross-coupled structure that needs diode-connected transistors and MTCMOS technique to converter ultra-low voltage signals.