A Fast and Energy-Efficient Level Shifter With Complementary Output Buffer for Energy-Constrained Systems

This brief presents a 55-nm level shifter (LS) that enables wide voltage range conversion from 80mV to 1.2V with high energy efficiency and fast transition speed. The proposed design incorporates a complementary output buffer and an assist discharge path to suppress the short-circuit current and enhance the transition speed. A multithreshold transistor strategy is adopted to expand the input range and reduce static power. Measurement results across 15 samples demonstrate robust subthreshold performance with 4.4-ns transition delay and 49.1-fJ/transition energy during 0.3–1.2-V conversion at 1MHz. The measured average minimum convertible input voltages are 80 and 139mV at input frequencies of 50kHz and 1MHz, respectively. The compact layout occupies only 7.96 $\mu $ m². Compared to the best benchmarked prior work, the proposed LS achieves 33.8% improvement in energy-delay metrics, making it a highly efficient and scalable solution for energy-constrained systems and the Internet of Things (IoT).