Battery Charge Controller Improves Efficiency

Jan 24, 2007 11:58 AM

Intersil’s ISL6257 is a narrow dc voltage charger controller for Li-ion/Li-ion polymer batteries in notebook computers. This device is designed to meet the NVDC-I requirements for better efficiency and longer battery life. Target applications are notebook, desknote and sub-notebook computers and personal digital assistants.

The charger offers good overall accuracy and features a narrow dc voltage output, which allows the system to operate from the regulated charger instead of the adapter. The use of the battery voltage as the system voltage as opposed to the output from the adapter allows the notebook to run at a maximum of 12.6 V instead of the adapter voltage, increasing the overall efficiency of the system as well as improving battery life and thermal management.

The charger provides ±0.5% charge voltage accuracy (-10°C to +100°C) for precise charge voltage, increasing battery life. This device also provides a ±3% accurate battery charge current limit for precise charge current control, allowing the maximum charge rate and further extending battery life.

Key features include an input voltage range of 7 V to 25 V, a battery-voltage set point up to 17.64 V, and less than 10 μA of battery leakage current. Other features include compatibility with aircraft power, support of any battery chemistry, and support of 2-, 3- and 4-cell battery packs.

The ISL6257 is available now in a 28-lead QFN package. Pricing is $3.42 in 1000-unit quantities.