How to Meet Host-Side Fuel Gauge System Design Challenges for Portable Devices

摘要

Smart phones, portable media players (PMPs) and personal digital assistants (PDAs) are essential to most everyone's life today. Determining the remaining battery capacity for these portable devices is just as critical. Users need to know with relative accuracy the remaining capacity or battery run-time over a battery life. Previously, many portable devices relied on voltage measurement alone to approximate the remaining battery capacity. The host-side fuel gauge, versus the traditional pack-side fuel gauge, has become much more attractive for this reporting. The host-side fuel gauge can reduce the end user's total cost for buying a replacement battery pack when the original battery life has expired. This article discusses how to improve fuel gauge accuracy and host-side battery management system design challenges including how to detect the battery's initial capacity upon insertion, coordinate operation with battery charging system, and minimize power consumption.