Energy efficient low static-power voltage level shifter

Abstract

Level shifter circuits are necessary parts of modern SoCs, as they interface different voltage domain signals. This paper presents an energy-efficient level up shifter capable of converting sub-threshold input signal to higher levels. The proposed design uses the feedback mechanism of a regulated gate cascode to achieve energy efficient operation. Once the desired output level is achieved, large static current does not flow, and static power is further minimized using a transistor stack. Implementing in a 90-nm process, post-layout simulation results show that the proposed level shifter has a propagation delay of 21.2 ns, a total energy-per-transition of only 77.5 fJ, and a static power dissipation of 7.2 nW.