AAT3693 Advanced Analogic Technologies, Inc., AAT3693 Datasheet - Page 13

• Manufacturer Part Number: AAT3693
• Description: 1.6a Lithium-ion/polymer Battery Charger In 2.2x2.2 Tdfn
• Manufacturer: Advanced Analogic Technologies, Inc.

BatteryManager
Application Information
Adapter or USB Power Input
Constant current charge levels up to 1.6A may be pro-
grammed by the user when powered from a sufficient
input power source. The AAT3693 will operate from the
adapter input over a 4.0V to 7.5V range. The constant
current mode fast charge current for the adapter input
is set by the R
ground. Refer to Table 1 for recommended R
for a desired constant current charge level; values are
rounded off to 1% standard resistance values.
Automatic Recharge
The AAT3693 has a UVLO and power on reset feature so
that if the input supply to the VIN pin drops below the
UVLO threshold, the charger will suspend charging and
shut down. When power is reapplied to the IN pin or the
UVLO condition recovers, the system charge control will
assess the state of charge on the battery cell and will
automatically resume charging in the appropriate mode
for the condition of the battery.
Enable / Disable
The AAT3693 provides an enable function to control the
charger IC on and off. The enable (EN) pin is internally
pulled down. When pulled to a logic high level, the
AAT3693 is enabled. When left open or pulled to a logic
low level, the AAT3693 will be shut down. Charging will
be halted regardless of the battery voltage or charging
state. When the device is re-enabled, the charge control
circuit will automatically reset and resume charging
functions with the appropriate charging mode based on
the battery charge state and measured cell voltage on
the BAT pin.
Programming Charge Current
The constant current mode charge level is user pro-
grammed with a set resistor placed between the ISET
pin and ground. The accuracy of the constant charge
current, as well as the preconditioning trickle charge
current, is dominated by the tolerance of the set resis-
tor used. For this reason, a 1% tolerance metal film
resistor is recommended for the set resistor function.
The constant charge current levels from 100mA to 1.6A
may be set by selecting the appropriate resistor value
from Table 1.
3693.2009.04.1.1
SET
resistor connected between ISET and
TM
1.6A Lithium-Ion/Polymer Battery Charger in 2.2x2.2 TDFN
w w w . a n a l o g i c t e c h . c o m
SET
values
Programmable Charge
Termination Current
The AAT3693 provides a user-programmable charge ter-
mination current at the end of the charge cycle. When
the battery cell voltage as sensed by the BAT pin reach-
es 4.2V, the charge control will transition from constant
current fast charge mode to constant voltage mode. In
constant voltage mode, the battery cell voltage will be
regulated at 4.2V. The charge current will drop as the
battery reaches its full charge capacity. When the charge
current drops to the programmed end of charge V
current, the charge cycle is complete and the charge
controller terminates the charging process.
If the TERM pin is left open, the termination current will
set to 10% of the constant charging current as the
default value.
Table 1: Constant Charging Current vs. R
Constant Charging
Figure 2: Charging Current vs. R
Current (mA)
10000
1000
100
10
1
0.1
1000
1250
1600
100
200
300
400
500
600
700
800
900
1
PRODUCT DATASHEET
R
SET
Set Resistor Value (kΩ)
10
AAT3693
(kΩ Ω )
Constant Charging Current
Pre-conditioning Current
100
0.866
16.5
8.06
5.36
4.02
3.16
2.67
2.26
1.87
1.78
1.47
1.18
SET
Values.
SET
1000
CO(REG)
.
13