Voltage scaling is one of the knobs that is used today to control both static and the active power for SoCs. The SoC core supply voltage is scaled adaptively based on the performance needs. But it is also required to maintain the external electrical chip interface protocol, which may run at a different voltage level. The chip interfaces need to operate reliably under adaptively scaling core voltage and fixed 10 supply voltage. Within the 10 circuits, voltage level shifters are used to communicate between two voltage domains. This paper examines the performance of a conventional voltage level shifter and describes a novel high performance level shifter that is more robust under adapting voltage scaling.