Subthreshold logic is showing good promise as a viable ultra-low-power circuit design technique for powerlimited applications. For this design technique to gain widespread adoption, one of the most pressing concerns is how to improve the robustness of subthreshold logic to process and temperature variations. We propose a variation resilient adaptive controller for subthreshold circuits with the following novel features: new sensor based on time-to-digital converter for capturing the variations accurately as digital signatures, and an all-digital DCDC converter incorporating the sensor capable of generating an
Biswajit Mishra, Bashir M. Al-Hashimi, Mark Zwolin