Expression of Concern: Supply Voltage Adaptive Low-Power Circuit Design

In this paper, we present a circuit design that is capable of responding to changes in the power supply voltage and adjust the gate size-ratio accordingly for minimum energy operation. The dynamically adjustable gate size-ratio allows the gate to preserve a symmetric voltage transfer characteristic at both normal supply and subthreshold operation. This translates to maximized noise margins over the whole range of the supply voltage. Simulation results show that the performance of the proposed circuit is superior to fixed gate sizes aimed at fixed supply operation. The proposed adaptive gate circuit design provide up to 6× reduction in the power-delay product in comparison with the fixed size gate.