DATA SHEET
AAT3685: Li-Ion/Polymer Battery Charger
Applications Description
Cellular telephones The AAT3685 BatteryManager is a highly integrated single cell
lithium-ion/polymer battery charger IC designed to operate with
Digital still cameras
USB port or line adapter inputs. It requires the minimum number
Hand-held PCs
of external components.
MP3 players
The AAT3685 precisely regulates battery charge voltage and
Personal Data Assistants (PDAs)
current for 4.2 V lithium-ion/polymer battery cells. Regardless of
Other lithium-ion/polymer battery-powered devices
the type of input power source (USB or adapter), the AAT3685 can
be programmed for two separate constant current charge levels
up to 1 A. An optional Charge Reduction Loop is built in to allow
Features
users to charge the battery with available current from the charge
Adapter or USB charger
supply, while keeping the port voltage regulated.
Programmable up to 1 A max.
Battery temperature and charge state are fully monitored for fault
conditions. In the event of an over-voltage or over-temperature
4.0 V to 5.5 V input voltage range
failure, the device will automatically shut down, thus protecting
High level of integration with internal:
the charging device, control system, and the battery under
Charging device
charge. Status monitor output pins are provided to indicate the
Reverse blocking diode
battery charge status by directly driving two external LEDs. A
Current sensing
serial interface output is available to report any one of 14 various
Automatic recharge sequencing
status states to a microcontroller.
Charge reduction loop
The AAT3685 is available in a Pb-free, thermally-enhanced,
space-saving 12-pin 3 3mm TDFN package and is rated over
Battery temperature monitoring
the 40 C to +85 C temperature range.
Full battery charge auto turn-off
A typical application circuit is shown in Figure 1. The pin
Over-voltage protection
configurations are shown in Figure 2. Signal pin assignments and
Emergency thermal protection
functional pin descriptions are provided in Table 1.
Power on reset and soft start
Serial interface status reporting
Skyworks Green products are compliant with
Pb-free, thermally-enhance TDFN (12-pin, 3 mm 3 mm)
all applicable legislation and are halogen-free.
package (MSL1, 260 C per JEDEC J-STD-020)
For additional information, refer to Skyworks
Denition of Green, document number
SQ04-0074.
Skyworks Solutions, Inc. Phone [781] 376-3000 Fax [781] 376-3100 sales@skyworksinc.com www.skyworksinc.com
201888C Skyworks Proprietary and Confidential Information Products and Product Information are Subject to Change Without Notice September 23, 2014 1 DATA SHEET AAT3685 LI-ION/POLYMER BATTERY CHARGER
Enable
EN
Adapter or USB Input ADP/USB CHR
BATT+
Input Hi/Lo Select PWRSEL
BAT
SETH C2
TS
10 F
AAT3685
RSETH
BATT
SETL
GND
RSETL
DATA
TEMP
STAT1 STAT2
Battery Pack
Serial Data
tc424
Figure 1. AAT3685 Typical Application Circuit
1 12
ADP/USB SETH
2 11
BAT SETL
3 10
GND PWRSEL
4 9
CHR STAT1
EN 5 8 STAT2
6 7
TS DATA
tc425
Figure 2. AAT3685 Pinout 12-Pin, 3 mm 3 mm TDFN
(Top View)
Table 1. AAT3685 Signal Descriptions
Pin Name Type Description
1 ADP/USB In Line adapter or USB power supply input.
2 BAT In/Out Battery charging and sensing.
3 GND Ground Ground connection.
Resistor divider to set USB voltage regulation for charge reduction mode. Leave this pin open for default 4.5 V USB
4 CHR In/Out
regulation point. Tie to ADP/USB pin to disable this function.
5 EN In Enable pin. Logic high enables the IC.
6 TS In/Out Connect to 10 k NTC thermistor.
7 DATA In/Out Status report to microcontroller via serial interface, open-drain.
8 STAT2 Out Battery charge status indicator pin to drive an LED: active low, open-drain.
9 STAT1 Out Battery charge status indicator pin to drive an LED: active low, open-drain.
10 PWRSEL In When ADP/USB is present, use this pin to toggle between SETH and SETL charging levels.
11 SETL In/Out Connect resistor here to set charge current for low-current port.
12 SETH In/Out Connect resistor here to set charge current for high-current port.
EP Exposed paddle (bottom); connect to GND directly beneath package.
Skyworks Solutions, Inc. Phone [781] 376-3000 Fax [781] 376-3100 sales@skyworksinc.com www.skyworksinc.com
2 September 23, 2014 Skyworks Proprietary and Confidential Information Products and Product Information are Subject to Change Without Notice 201888C