Cross-coupled high-speed, low power level shifter

Abstract

Described is a high speed, low power level shifter circuit which includes a cross-coupled level shifter coupled to a sensing circuit. The sensing circuit turns off a cross-coupled node of a pair of cross-coupled nodes based on detecting that an input voltage has crossed a threshold voltage for a cross-coupled input transistor of a pair of cross-coupled input transistors, i.e. due to switching from a current logic level to an incoming logic level. Once the sensing circuit detects a threshold voltage crossing, a pull-up circuit pulls high a cross-coupled node and cross-coupled source transistor tied to the cross-coupled node. This turns off the cross-coupled source transistor and turns on another cross-coupled source transistor. Two parallel paths are now established to pull the cross-coupled node high, enabling a high-speed transition. The turning off of the cross-coupled source transistor also pulls the output to the incoming logic level.