Analogic Tech Expands Battery Charger IC Product Family

Advanced Analogic Technologies Inc., a developer of power management semiconductors for mobile consumer electronic devices, has announced the AAT3685, a single-cell lithium-ion/polymer battery charger integrated circuit capable of operating from an ac line adapter or universal serial bus (USB) port output. Depending upon port type, this device supports constant charge currents up to 1A.

"Cell phone and other battery-powered device manufacturers are always trying to give their customers as much flexibility as possible," said Bill Weiss, AnalogicTech's product line director for battery manager ICs. "Since the AAT3685 can be programmed for two separate constant current charge levels up to 1A, users can now charge their device from either an ac source or any USB port without compromising their fast charge rate."

Designed to regulate battery charge voltage and current for any 4.2V lithium-ion/polymer battery cell, the AAT3685 combines a charging device, reverse blocking diode, and current sensing circuit in a 3x3mm thin dual flat no-lead (TDFN) package. A charge reduction loop minimizes charge time by allowing users to charge the battery with available current from the charge supply while keeping the port voltage regulated. Such dynamic control of the charge current enables the fastest possible charge time while sharing the port supply. This feature automatically compensates for voltage sags and ensures the battery charger will not overload the USB port if other system applications share power with the port supply.

The AAT3685 also offers a wide variety of protection features to ensure the integrity of the charger and the battery. Battery temperature and charge state are continually monitored for fault conditions. Over-voltage and over-temperature circuits automatically shut down the device in the event of a failure. Status monitor output pins are provided to drive two external light-emitting diodes to indicate battery charge status. The device also adds a serial interface output that can report any of 14 different status states to a microcontroller.

The AAT3685 is rated over the -40 C to +85 C temperature range and is immediately available in a lead-free, thermally enhanced, 12-pin, 3x3mm TDFN package. The device sells for $1.20 in 1000-unit quantities.

Advanced Analogic Technologies is a supplier of power management semiconductors for mobile consumer electronic devices, such as wireless handsets, notebook and tablet computers, smartphones, digital cameras, and digital audio players.