Very low thermal drift precision virtual voltage reference

A digital-based, process-supply-and-temperature independent voltage reference suitable to nanoscale CMOS technologies, which exploits the recently proposed `virtual reference´ concept to achieve a very low thermal drift, is presented. Its performance is assessed on the basis of simulations and experiments carried out on a microcontroller-based, proof-of-concept prototype and is compared with state-of-the-art integrated analogue and digital voltage references. A simulated (measured) thermal drift as low as 1 ppm/°C (5 ppm/°C) in the temperature range -40/+140°C (-10/+100°C) is reported.