High power density 2A battery charger requires less PCB space

4th April 2007

Advanced Analogic Technologies Inc., Europe

ES Admin

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Power density is an increasingly important consideration in a wide variety of high performance handheld systems like smart phones, GPS systems and portable media players that use high capacity batteries. Addressing this need, a linear charger from AnalogicTech offers the industry’s highest charge-current-to-solution-footprint ratio while the integration of the company’s intelligent digital thermal loop feature enables the host system to use a high current linear charger without the risk of pulse charging the battery. The AAT3697 is an extremely high power density linear battery charger for Lithium-ion/polymer batteries. Coming in a small, 12-pin, 3x3mm TDFN package, the latest addition to AnalogicTech’s rapidly expanding battery charger product line offers up to 2A of charge current while occupying only 9mm2 of PCB area.

The device integrates an internal charging device, reverse blocking, and current sensing circuits. An intelligent digital thermal loop control system continuously measures internal circuit temperature and automatically reduces the fast charge current when the device exceeds a preset die temperature threshold. By constantly evaluating the die temperature and adjusting the fast charge current only to the extent necessary, this closed-loop thermal management system maximises charge current and minimises charge time, even under harsh high temperature operating conditions.

The AAT3697 continuously monitors battery temperature and charge state for fault conditions. If an over-voltage or over-temperature condition occurs, the device automatically shuts down to protect the charging device, the control system and the battery under charge. A battery charge timer also protects the battery and the system by terminating charge if the user-programmable charge time is exceeded.

The battery charger also features two status monitor output pins capable of driving external LEDs to indicate charge status. A serial interface output can be used to report any of 12 charge states to the system microcontroller.

The AAT3697 is available in a Pb-free, thermally-enhanced, 12-pin TDFN 3x3mm package and is rated over the -40 to +85 degrees C temperature range.