Abstract
ill Park , Student Member , IEEE, and Kaushik Roy , Fellow, IEEE
Abstract—Supply voltage scaling is one of the easiest ways to
reduce energy dissipation. Therefore, researchers have considered
subthreshold logic as a promising option to achieve ultra low en-
ergy dissipation. However, circuit propagation delay is extremely
sensitive to PVT variations under subthreshold operation. Hence,
large delay margin is required for successful operation of conven-
tional synchronous designs. Since leakage e