AAT3685IWP-4.2-T1 Analogic Tech, AAT3685IWP-4.2-T1 Datasheet - Page 10

• Manufacturer Part Number: AAT3685IWP-4.2-T1
• Description: Battery Management Lithium-Ion/Polymer Battery Charger
• Manufacturer: Analogic Tech

Specifications of AAT3685IWP-4.2-T1

• Package / Case: TDFN33-12
• Mounting Style: SMD/SMT
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Functional Block Diagram
Functional Description
The AAT3685 is a highly integrated single cell lithium-
ion/polymer battery charger IC designed to operate from
adapter or USB port V
minimum number of external components. The device
precisely regulates battery charge voltage and current
for 4.2V lithium-ion/polymer battery cells.
The AAT3685 is specifically designed for being powered
from a USB port V
from any input voltage source capable supplying 4.5V to
5.5V for loads up to 1A. The AAT3685 constant charge
current can be externally programmed for two levels,
SETH and SETL, for maximum constant current charge
levels up to 1A.
Charge Reduction Loop control to allow users to charge
the battery with limited available current from a port
while maintaining the regulated port voltage. This sys-
tem assures the battery charge function will not overload
the port while charging if other system demands also
share power with the respective port supply.
10
10
BatteryManager
BatteryManager
BUS
The SETH/L mode has an automatic
supply, but it can also be powered
ADP/USB
TM
TM
PWRSEL
BUS
STAT1
STAT2
DATA
SETH
SETL
CHR
supplies, while requiring a
EN
Reduction
Charge
Loop
w w w . a n a l o g i c t e c h . c o m
w w w . a n a l o g i c t e c h . c o m
Charge
Status
Serial
Data
Constant
Compare
Current
Current
IC enable
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 14
various charge states to a system microcontroller.
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 battery under charge.
internal charge controller thermal protection, the AAT3685
also provides a temperature sense feedback function (TS
pin) from the battery to shut down the device in the
event the battery exceeds its own thermal limit during
charging. All fault events are reported to the user either
by the simple status LEDs or via the DATA pin function.
Charging Operation
The AAT3685 has four basic modes for the battery
charge cycle and is powered from the input: pre-condi-
tioning/trickle charge; constant current/fast charge;
constant voltage; and end of charge. For reference,
Figure 1 shows the current versus voltage profile during
charging phases.
Lithium-Ion/Polymer Battery Charger
Lithium-Ion/Polymer Battery Charger
Control
Charge
Reverse Blocking
Window
Comparator
GND
Temperature
Precharge
Protect
UVLO
Over-
CV/
PRODUCT DATASHEET
PRODUCT DATASHEET
80μA
BAT
TS
AAT3685
AAT3685
3685.2007.12.1.4
3685.2007.12.1.4
In addition to