AAT3683_08 Datasheet, PDF (10/23 Pages) Advanced Analogic Technologies – 1A Linear Li-Ion Battery Charger

BatteryManager^TM
Functional Block Diagram
PRODUCT DATASHEET
AAT3683
1A Linear Li-Ion Battery Charger
Reverse Blocking
IN
BAT
Current
Compare
CV/ Pre-
charge
ISET
Constant
Current
ADPP#
(3683-2/-3 only)
Power
Detection
Charge
Control
75μA
(3683-2 only)
TS
IC Enable
Watchdog
Window
Timer
Comparator
UVLO
Over-
Temp.
Protect
Battery OV
Protection
Thermal
Loop
Charge
Status
STAT (3683-2/-3 only)
STAT1 (3683-4 only)
STAT2 (3683-4 only)
EN
CT
GND
Functional Description
The AAT3683 is a high performance battery charger
designed to charge single-cell lithium-ion or lithium-
polymer batteries with up to 1A of current from an exter-
nal power source. It is a stand-alone charging solution,
with just one external component required for complete
functionality.
The AAT3683 precisely regulates battery charge voltage
and current for 4.2V lithium-ion/polymer battery cells
with constant current level being programmed up to 1A
for rapid charging applications. The charge termination
current can be programmed by an external resistor.
The AAT3683 is rated for operation from -40°C to +85°C.
In the event of operating ambient temperatures exceed-
ing the power dissipation abilities of the device package
for a given constant current charge level, the charge
control will enter into thermal limit.
AAT3683-2 and -3 provide one status monitor output pin
(STAT) by directly driving one external LED to indicate
the battery charging state. AAT3683-4 provides two sta-
tus pins to indicate the battery charging state.
Device junction temperature and charge state are fully
monitored for fault conditions. In the event of an over-
voltage or over-temperature failure, the device will auto-
matically shut down, protecting the charging device,
control system, and the battery under charge.
During battery charging, the device temperature will
rise. In some cases with adapter (ADP) charging, the
power dissipation in the device may causethe junction
temperature to rise to close to its thermal shutdown
threshold. In the event of an internal over-temperature
condition caused by excessive ambient operating tem-
perature or excessive power dissipation condition, the
AAT3683 enables a digitally controlled thermal loop sys-
tem that will reduce the charging current to prevent the
device from thermal shutdown. The digital thermal loop
will maintain the maximum possible battery charging
current for the given set of input to output power dissi-
pation and ambient temperature conditions.
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3683.2007.11.1.2