AAT3672 Datasheet, PDF (12/27 Pages) Skyworks Solutions Inc. – 1.6A Dynamic Battery Charger and Power Manager

Functional Block Diagram
DATA SHEET
AAT3672
1.6A Dynamic Battery Charger and Power Manager
ADP
ADP to OUT Switch
OUT
EN/EN1
ENO
ENBAT
CT
TERM
ADPSET
CHRADP
STAT1
STAT2/EN2
Charge
System
Control
Voltage
Sense
Ref.
Thermal and
Current Sense
BAT
TS
GND
Functional Description
The AAT3672 is a single input dynamic battery charger
and power control IC. The input power control is designed
to be compatible with either AC power adapter or USB
port power sources. In addition, this device also provides
dynamic power control to charge a single cell Li-ion bat-
tery and power a system load simultaneously.
The device contains three pass devices to control the
charge current or voltage from the adapter input power
to the battery and system load. It also contains an addi-
tional load switch to control and manage power from the
battery to the system load. This charge control and
switch array permits dynamic charging of the battery cell
and control of power to the system load simultaneously.
When an input power source is applied to the AAT3672,
the adapter input will provide power to the system load
and charge the battery. Without a valid supply present
on the ADP pin, the battery will power the system load
as long as the battery voltage is greater than 2.9V. The
internal battery voltage sense circuit will disconnect the
battery from the load if the cell voltage falls below 2.9V
to protect the battery cell from over-discharge which
results in shorter battery life.
The system load current drawn from the battery is lim-
ited internally. The AAT3672 precisely regulates battery
charge current and voltage for 4.2V Li-ion battery cells.
The battery charge current can be programmed up to
1.6A. During battery charge, the AAT3672 pre-conditions
(trickle charge) the battery with a lower current when
the battery voltage is less than 2.9V, the system then
charges the battery in a constant current fast charge
mode when the battery voltage is above 2.9V. When the
battery voltage rises to 4.2V, the charger will automati-
cally switch to a constant voltage mode until the charge
current is reduced to the programmed charge termina-
tion current threshold.
The internal arrangement of load switches and the charge
regulation device provide dynamic power sourcing to the
system load. If the system load exceeds the input current
supply from the input source, additional current can be
supplied from the battery cell. At all times, the device will
manage distribution of power between the source, the
battery and the system simultaneously in order to support
system power needs and charge the battery cell with the
maximum amount of current possible. The AAT3672 has
a unique internal charge current reduction loop control
that will prevent an input source from overload. In the
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [e-mail] • www.skyworksinc.com
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201880B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 25, 2012