Performance Prospect of Low‐Power Bulk MOSFETs

For the medium performance medium power region of the design spectrum, reduction in supply voltage affects performance unless the threshold voltage is suitably scaled. Reduction in the threshold voltage, however, increases the OFFstate leakage. A tradeoff between power and performance is therefore necessary for this region of the design spectrum. Ultralow power circuits can be designed by using a supply voltage, which is below the threshold voltage of the devices, resulting in subthreshold circuits. High performance cannot be expected from such circuits as the drive current is extremely low in the subthreshold regime. This therefore leads us to one of the two extreme ends of the design spectrum that can deliver integrated circuits (ICs) with ultralow power but with only acceptable performance. Applications of such subthreshold circuits that do not require high performance include medical equipment such as pacemakers and hearing aids, self‐power devices, and processing of the signal from different sensors, and so on.