AnalogicTech Presents AAT3686 Battery Charger IC

Advanced Analogic Technologies Inc. (AnalogicTech, Sunnyvale, CA), a developer of power management solutions, presented the new AAT3686, a lithium-ion/polymer battery charger IC designed to operate off both USB and ac adapter inputs. The AAT3686 charger features a digital thermal loop and a charge reduction loop that allows users to charge the battery with available current from the USB port while keeping the port voltage regulated. The latter feature ensures the battery charge function will not overload the USB port if other system loads share power with the port supply.

The AAT3686 also adds a digital thermal loop control system that maximizes charging current by measuring internal circuit die temperature and reducing that fast charge current when the circuit die temperature exceeds preset thresholds. For rapid charging, the AAT3686 supports programmable adapter charge current rates up to 1.5 A. The USB charge rates can be programmed to two levels, USB high and USB low, up to a maximum current level of 500 mA. The USB charging is automatically disabled when an adapter is present.

The AAT3686 provides a variety of features to protect the integrity of the charging device, the control system, and the battery under charge. Battery temperature and charge state are constantly monitored for fault conditions. Over-voltage and over-temperature protection circuits automatically shut down the device in the event of a failure. Status monitor output pins indicate battery charge status by directly driving two external LEDs. The AAT3686 can also report up to 22 different charging status states to a microcontroller via a serial interface output.

The AAT3686 is available in a lead-free, thermally enhanced, 16-pin, 4 mm x 4 mm TDFN package. The device sells for $1.64 in 1,000-piece quantities.