Ultra-low voltage VLSI: are we there yet?

Aggressively scaled supply voltage has been touted as one of the most powerful mechanisms for improving reliability and reducing power consumption in nanometer technologies. Sophisticated adaptive power management techniques vary supply voltage from nominal to ultra-low values to implement adaptive VLSI systems that gracefully respond to varying workload demands for improved energy efficiency. Unfortunately, ultra-low voltage (sub-volt for current technologies) operation has been constrained by performance limitations. In this paper, the current state of low-voltage VLSI design is evaluated; techniques for maintaining acceptable throughputs at ultra-low voltages are reviewed; and trends and prospects for ultra-low voltage VLSI systems are presented