AAT3673 Datasheet, PDF (13/28 Pages) Skyworks Solutions Inc. – 1.6A Dynamic Battery Charger and Power Manager

Functional Block Diagram
DATA SHEET
AAT3673
1.6A Dynamic Battery Charger and Power Manager
BYP
ADP
EN/EN1
ENO
ENBAT
CT
TERM
ADPSET
CHRADP
STAT1
STAT2/EN2
OVP
Sense
And
Control
ADP to OUT Switch
OUT
Charge
System
Control
Voltage
Sense
Ref.
Thermal and
Current Sense
BAT
TS
GND
Functional Description
The AAT3673 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 OUT
pin provides regulated 4.4V when input requirement is
met. If the input voltage is not sufficiently high to ensure
regulated OUT, the output will track input assuming the
drop through the switch ADP to BAT or BAT to OUT.
The device contains a charge regulation pass devices to
control the charge current or voltage from the adapter
input power to the battery, it also contains two addi-
tional load switches to control and route input power to
supply the system load and manage power from the bat-
tery 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 AAT3673,
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 AAT3673 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 AAT3673 pre-conditions
(trickle charges) 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.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [e-mail] • www.skyworksinc.com
201881B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 25, 2012
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