A high efficiency Digital PWMDC-DC converter using hybrid control technique for EH applications

Abstract

We have proposed a DC-DC Converter with high efficiency for ultra-low power Energy Harvesting (EH) applications. To achieve the high efficiency while remaining the high accuracy, the control signal pulse width is generated digitally instead of analog as in the conventional DC-DC converter. The presented Digital Pulse Width Modulation (DPWM) DC-DC converter employs the hybrid control technique which consists of the counter based and the open delay locked loop based topology. The output range of this converter can be from 4.5V to 6V by using 3-bits control with the trimming step of 20 mV. The power conversion efficiency of the proposed converter is 93% at 500mA load. Our proposed buck DC-DC converter is realized with CMOS 0.18 μm technology with the die size of 1200 μm × 980 μm.