Advanced Analogic Technologies Inc. (AnalogicTech) announced the AAT3663, the first in a family of new 1A linear battery charger ICs capable of charging up to two Li-ion cells in series. Designed to operate from either an ac adapter or a USB port, this new device features AnalogicTech’s Digital Thermal Loop charge reduction circuit which monitors the internal die temperature and gradually steps down the charge current to avoid thermal shutdown.
"A growing number of products, from Portable Media Players (PMPs) and digital cameras to point of sale (POS) solutions and high-end handsets, are powered today by two Li-Ion cells connected in series," said Siamak Bastami, Product Line Director for AnalogicTech. "By supporting input voltages up to 13.2V, the AAT3663 offers designers the opportunity to replace larger and more expensive discrete charging solutions with a high integrated and more cost effective alternative."
The AAT3663 operates across a 4.0 to 13.2V input voltage range and supports user programmable charge current from 100mA up to 1A via an external resistor. Quiescent current is less than 6µA. The device features an intelligent digital thermal loop charge reduction circuit which optimizes battery charge rate by constantly measuring die temperature and adjusting the charge current to compensate for thermal conditions. The closed loop thermal management system allows the charger to continue charging even under harsh environmental conditions, therefore minimizing charge time.
The new charger IC also features a programmable charge termination current feature which sends the device into sleep mode if the charging current dips below a pre-defined threshold. An integrated programmable charge timer can be used to shut down charging functions if a defective battery cell or a disconnection to the battery current path is detected.
The AAT3663 continuously monitors battery temperature and charge state for fault conditions. To protect the charging device, and the battery under charge, integrated over-temperature, short-circuit, over-voltage and over-current protection circuits automatically shuts down the device if a fault occurs.
Specified for operation across the -40 to +85C temperature range, the AAT3663 is available in a thermally-enhanced 14-pin, 3×3-mm TDFN package. It sells for $1.38 in 1K quantities.