10 MHz boost converter with subthreshold voltage startup and predictive dead‐time techniques for energy‐harvesting systems

Abstract

A 10 MHz synchronous boost converter with the subthreshold startup scheme and predictive dead-time control for energy-harvesting systems is presented in this study. The input feed-forward technique is adopted to achieve a fast line response, and a three-stage startup technique is proposed to realise subthreshold voltage startup without using any extra startup circuits or special devices. Moreover, the efficiency of the high-frequency converter can be improved by the proposed predictive dead-time control with a high resolution of ∼300 ps. The proposed converter is implemented in a standard 0.18 μm complimentary metal oxide semiconductor process and occupies a die area of 1.4 × 1.5 mm 2 . Experimental results show that the input voltage ranges from 0.3 to 1.5 V at 1.8 V output, and the minimum startup voltage is 0.3 V. Under V IN = 1.5 V, V OUT = 1.8 V and 150 mA load, the power efficiency can be improved by 2.6% because of the proposed predictive dead-time control. The peak efficiency can reach 90.7% under V IN = 1.5 V. The line transient response can be improved with small overshoot voltage at the output.