Ultra-low voltage datapath blocks in 28nm UTBB FD-SOI

This paper demonstrates a wide supply range multiply-accumulate datapath block in 28nm UTBB FD-SOI technology. Variability and leakage reduction strategies are employed in this new technology to achieve a state-of-the-art low energy performance. The design uses a wide range of supply voltages to reduce energy consumption per operation. The extensive back-gate biasing range allows to adapt the minimum energy point (MEP) of the circuit to the desired workload. Measurements showcase the speed/energy trade-off of both the design and the technology and lead to a MEP of 0.17pJ at 35MHz with a supply voltage of 250mV and a back-gate bias of 0.5V.