Lithium-Ion/Polymer Battery Charger
General Description
The AAT3685 BatteryManager™ is a highly inte-
grated single cell lithium-ion/polymer battery charg-
er IC designed to operate with USB port or line
adapter inputs. It requires the minimum number of
external components.
The AAT3685 precisely regulates battery charge volt-
age and current for 4.2V lithium-ion/polymer battery
cells. Regardless of the type of input power source
(USB or adapter), the AAT3685 can be programmed
for two separate constant current charge levels up to
1A. An optional Charge Reduction Loop is built in to
allow users to charge the battery with available cur-
rent from the charge supply, while keeping the port
voltage regulated.
Battery temperature and charge state are fully
monitored for fault conditions. In the event of an
over-voltage or over-temperature failure, the
device will automatically shut down, thus protecting
the charging device, control system, and the bat-
tery under charge. Status monitor output pins are
provided to indicate the battery charge status by
directly driving two external LEDs. A serial interface
output is available to report any one of 14 various
status states to a microcontroller.
The AAT3685 is available in a Pb-free, thermally-
enhanced, space-saving 12-pin 3x3mm TDFN
package and is rated over the -40°C to +85°C tem-
perature range.
AAT3685
Features
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BatteryManager
™
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Adapter or USB Charger
— Programmable up to 1A Max
4.0V to 5.5V Input Voltage Range
High Level of Integration With Internal:
— Charging Device
— Reverse Blocking Diode
— Current Sensing
Automatic Recharge Sequencing
Charge Reduction Loop
Battery Temperature Monitoring
Full Battery Charge Auto Turn-Off
Over-Voltage Protection
Emergency Thermal Protection
Power On Reset and Soft Start
Serial Interface Status Reporting
12-Pin 3x3mm TDFN Package
Applications
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Cellular Telephones
Digital Still Cameras
Hand-Held PCs
MP3 Players
Personal Data Assistants (PDAs)
Other Lithium-Ion/Polymer Battery-Powered
Devices
Typical Application
Enable
Adapter or USB Input
Input Hi/Lo Select
ADP/USB
PWRSEL
SETH
R
SETH
R
SETL
SETL
BAT
TS
C2
10μF
EN
CHR
BATT+
AAT3685
GND
BATT-
DATA
STAT1
STAT2
TEMP
Battery Pack
Serial Data
3685.2006.10.1.3
1
AAT [ ADVANCED ANALOG TECHNOLOGY, INC. ]
