A Digital-Based Virtual Voltage Reference

A novel virtual reference concept is introduced in this paper to design accurate, mostly digital, software-defined, process-supply-and-temperature (PVT)-independent voltage references suitable to replace conventional analog reference circuits in present day, low voltage, aggressively scaled, mainly digital integrated systems. The operation and the performance of references based on the proposed approach are tested by computer simulations and experiments carried out on a proof-of-concept, microcontroller-based prototype, reporting a measured thermal drift of 16 ppm/degrees C in a range from -10 degrees C to 100 degrees C and a line regulation of 0.15%/V. The advantages in terms of costs and performance of the proposed digital references in comparison with state-of-the-art analog solutions are finally discussed.