USB Port or AC Adapter
Lithium-Ion/Polymer Battery Charger
General Description
The AAT3681 BatteryManager is an integrated sin-
gle cell lithium-ion/polymer battery charger IC,
designed to operate from a DC power source or
USB port up to an input voltage of 6.5V. It requires
just one external component.
The AAT3681 precisely regulates battery charge
voltage and current for 4.2V (4.375V option) lithium-
ion/polymer battery cells. When charged from an
AC adapter or USB port, the battery charging cur-
rent can be set by an external resistor up to 300mA.
Battery charge state is continuously monitored for
fault conditions. In the event of an over-voltage,
short-circuit, or over-temperature failure, the
device will automatically shut down, thus protecting
the charging device, control system, and the bat-
tery under charge. A status monitor output pin is
provided to indicate the battery charge status by
directly driving an external LED.
The AAT3681 is available in a Pb-free, thermally
enhanced, space-saving 8-pin 2.0x2.1mm SC70JW
package and is specified for operation over the
-40°C to +85°C temperature range.
AAT3681
Features
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BatteryManager
™
USB or AC Adapter System Power Charger
— Programmable from 15mA to 300mA
4.0V ~ 6.5V Input Voltage Range
High Level of Integration with Internal:
— Charging Device
— Reverse Blocking Diode
Automatic Current Sensing
Automatic Recharge Sequencing
Full Battery Charge Auto Turn Off/Sleep
Mode/Charge Termination
Shutdown Current <1µA
Automatic Trickle Charge for Battery Pre-
Conditioning (AAT3681-1 is No Trickle Charge
Option)
Over-Voltage and Emergency Thermal
Protection
Power On Reset and Soft Start
LED Status Pin
8-Pin 2.0x2.1mm SC70JW Package
Applications
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Bluetooth
®
Headsets
DECT Headsets
Digital Still Cameras
MP3, Portable Music, and Portable Media
Players
Personal Data Assistants (PDAs)
Wrist Watches
Other Lithium-Ion/Polymer Battery-Powered
Devices
Typical Application
Adapter/USB Input
ADP
BAT
BATT+
AAT3681
Enable
STAT
EN
ISET
GND
C
BATT-
Battery
Pack
R
SET
3681.2007.01.1.2
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