A 30mV input battery-less power management system

Jim Hui Yap,Yan Chiew Wong

doi:10.11591/eei.v8i4.1614

Abstract

This paper presents a fully-integrated on chip battery-less power management system through energy harvesting circuit developed in a 130nm CMOS process. A 30mV input voltage from a TEG is able to be boosted by the proposed Complementary Metal-Oxide-Semiconductor (CMOS) voltage booster and a dynamic closed loop power management to a regulated 1.2V. Waste body heat is harvested through Thermoelectric energy harvesting to power up low power devices such as Wireless Body Area Network. A significant finding where 1 Degree Celsius thermal difference produces a minimum 30mV is able to be boosted to 1.2V. Discontinuous Conduction Mode (DCM) digital control oscillator is the key component for the gate control of the proposed voltage booster. Radio Frequency (RF) rectifier is utilized to act as a start-up mechanism for voltage booster and power up the low voltage closed loop power management circuit. The digitally control oscillator and comparator are able to operate at low voltage 600mV which are powered up by a RF rectifier, and thus to kick-start the voltage booster.

Highlights

Energy harvesting topic has been widely discussed as it has become a potential alternative way to replace conventional battery
Wireless Body Area Network (WBAN) is one of the applications that expected to operate for long durations but energy supply becomes a severe bottleneck and much effort has been spent on the efficient use of battery energy
Voltage booster Voltage booster is a DC-DC converter to step up small signal DC to an output DC signal which is greater than input signal

Summary

Introduction

Energy harvesting topic has been widely discussed as it has become a potential alternative way to replace conventional battery. This is due to the demand of low power, small size and maintanence free operation of electronic devices has been increased. While a small battery needs a frequent charging and replacement which reduce the wearable compliance. One of the main problems about pacemakers is their batteries. A battery is not recommended to be placed inside the human body as it may contact with blood (such as pH sensor) [2]

Methods

Results

Conclusion