A Fully Integrated and Battery-Free Interface for Low-Voltage Electromagnetic Energy Harvesters

Ulusan H., Gharehbaghi K., Zorlu O., Muhtaroglu A., KÜLAH H.

IEEE TRANSACTIONS ON POWER ELECTRONICS, vol.30, no.7, pp.3712-3719, 2015 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 30 Issue: 7
  • Publication Date: 2015
  • Doi Number: 10.1109/tpel.2014.2344915
  • Journal Name: IEEE TRANSACTIONS ON POWER ELECTRONICS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.3712-3719
  • Keywords: Electromagnetic (EM) power generation, fully integrated interface electronics, low-voltage ac/dc conversion, self-powered rectifier, vibration-based energy harvesting, BOOST CONVERTER, CIRCUIT, SYSTEM, RECTIFIER
  • Middle East Technical University Affiliated: Yes

Abstract

This paper presents a fully integrated and battery-free 90 nm interface circuit for ac/dc conversion and step up of low-voltage ac signals generated by electromagnetic (EM) energy harvesters. The circuit is composed of two stages: The rectifier in the first stage utilizes an improved ac/dc doubler structure with active diodes internally powered by a passive ac/dc doubler and custom-designed comparators to minimize the voltage drops. With this, the efficiency is enhanced to 67% while providing 0.61 V to 40 mu A load. The second stage is a dc/dc converter utilizing a low-voltage charge pump with an on-chip ring oscillator for further voltage step up. The rectifier stage is functional down to 125 mV input peak voltage, and the full interface circuit can maintain more than 1 V dc at 1 M Omega load for input peak voltages higher than 0.4 V. The circuit delivers 2.48 V to a 4.4 M Omega load, when interfaced to an in-house EM harvester, operating under 10 Hz, 0.5g vibration.