AAT3670

The AAT3670 BatteryManager is a highly integrated single- cell lithium-ion/polymer (Li-ion) battery charger and system power management IC that enables simultaneous battery charging and full system usage without compromising the battery's charge cycle life. It operates with low-voltage AC adapter (ADP) and USB inputs and requires a minimum number of external components.

The AAT3670 selects ADP or USB to power the system load and charge the battery when ADP/USB power is available. The AAT3670 precisely regulates battery charge voltage and current for 4.2V Li-ion cells. Charge current can be programmed up to 1.6A for ADP charging and 0.9A or 0.1A for USB charging by resistors on the ADPSET / USBSET pins. The charge termination current threshold is set by an external resistor on the TERM pin.

The AAT3670 has a voltage-sensed charge current reduction loop that enables system operation without a power shortage. When the input voltage falls below the programmable charge reduction threshold, the device automatically reduces the charge current until the input voltage returns to the threshold voltage.

Battery temperature and charge state are fully monitored for fault conditions. In the event of a battery over-voltage/ short-circuit/over-temperature condition, the charger will automatically shut down, protecting the charging device, control system, and battery. Two status monitor output pins (STAT1 and STAT2) are provided to indicate battery charge status by directly driving external LEDs.

The AAT3670 is available in a Pb-free, thermallyenhanced, space-saving 24-pin 4x4mm QFN package.