Integrated power management for microsystems

Abstract

There is a need for a universal power module for microsystems. This module should provide power conditioning, energy storage, and load matching for a variety of energy sources and loads such as microelectromechanical systems (MEMS) and wireless sensors and micro-robots. There are a variety of potential ambient and human powered energy sources, which can supply some of the power needs of the military. The challenge is to capture these available sources of electrical energy and condition them to meet the voltage, current, and overall power demands of field-deployable microelectronics and MEMs-based devices such as wireless sensors and micro-robots. Most natural and man-made energy sources found in the environment have a low specific power and are not generally available on a continuous basis. Likewise, human-based energy sources must be optimally managed to meet the power needs in the field. Therefore, a power supply must have the ability to capture the available energy and store it in such a manner to be useful to meet the mission requirements of the device that is connected to the source. It must continuously monitor the status of energy stored and determine the expected demands of the device. A microelectronics-based power management chip can be developed to meet these objectives. The major challenge in realizing this concept will be the design of an intelligent power-conditioning chip that consumes a minimum of power to perform the functions of power conditioning, storage, load matching, and status monitoring. The prototype power conditioning integrated circuit would be capable of delivering a peak power of 100 mW at 5 V. The nominal operating condition would be a very low duty cycle for a relatively high power load, and a low-power source available for long periods of time, or a moderate-power source available intermittently