201885B.pdf

DATA SHEET
AAT3683
1A Linear Li-Ion Battery Charger
General Description
Features
The AAT3683 BatteryManager is a highly integrated single-cell lithium-ion / polymer (Li-Ion) battery charger
that operates from a USB port or an AC adapter input up
to an input voltage of 7.5V.
•
•
•
•
The AAT3683 precisely regulates battery charge voltage
and current for 4.2V Li-Ion battery cells. The battery
charging current can be set by an external resistor up to
1A.
Digital Thermal Loop Control maintains the maximum
possible battery charging current for the given set of
input to output power dissipation and ambient temperature conditions.
Battery charge state is continuously monitored for fault
conditions. In the event of an over-current, over-voltage,
short-circuit, or over-temperature condition, the device
will shut down automatically, thus protecting the charging device, control system, and the battery under
charge. A status monitor output pin is provided to indicate the battery charge status by directly driving an
external LED. An open-drain power source detection output is provided to report the power supply status.
The AAT3683 is available in the Pb-free, thermallyenhanced, space-saving 2.2 x 2.2mm 10-pin STDFN
(AAT3683-2) and 16-pin QFN33 (AAT3683-4) packages
and is specified for operation over the -40°C to +85°C
temperature range.
•
•
•
•
•
•
•
•
•
•
•
•
•
•
USB or AC Adapter Input
Programmable from 100mA to 1A
4.0V to 7.5V Input Voltage Range
High Level of Integration with Internal:
▪ Charging Device
▪ Reverse Blocking Diode
▪ Current Sensing
Digital Thermal Regulation
Charge Current Programming (ISET)
Charge Termination Current Programming (TERM)
Charge Timer (CT)
Battery Temperature Sensing (TS)
TS Pin Open Detection
Automatic Recharge Sequencing
Automatic Trickle Charge for Battery Pre-Conditioning
(no trickle charge option available)
Full Battery Charge Auto Turn-Off / Sleep Mode /
Charge Termination
1μA Max. Shutdown Current
Over-Voltage and Over-Current Protection
Emergency Thermal Protection
Power On Reset and Soft Start
2.2 x 2.2mm STDFN-10 (AAT3863-2) and QFN33-16
(AAT3683-4) Packages
Applications
•
•
•
•
•
Bluetooth Headsets, Headphones, Accessories
Cellular Phones
Digital Still Cameras
MP3, Portable Music, and Portable Media Players
Personal Data Assistants (PDAs) and Handheld
Computers
• Other Li-Ion Battery-Powered Devices
Typical Application
ENABLE
ENABLE
BATT+
EN
IN
VIN
BATT+
EN
BAT
VIN
C IN
IN
BAT
CBAT
C IN
CBAT
BATTBATT
TERM
RT
TERM
AAT3683-2
R TERM
STAT
TEMP
ADPP#
R TERM
STAT1
TEMP
TS
TS
STAT2
CT
CT
AAT3683-4
BATT-
ISET
GND
R SET
Battery
Pack
CT
CT
ISET
GND
R SET
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com
201885B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 25, 2012
Battery
Pack
1
DATA SHEET
AAT3683
1A Linear Li-Ion Battery Charger
Pin Descriptions
Pin
Name
Type
n/a
16
STAT
STAT1
O
2
2
TERM
3
4
5
n/a
3
4
n/a
5
GND
CT
ADPP#
STAT2
6
7
TS
I/O
7
8
9
10
6
15
11
12
1, 8, 9, 10,
13, 14
BAT
IN
ISET
EN
O
AAT3683-2
AAT3683-4
1
n/a
n/a
I
O
I
N/C
Function
Charge status pin, open drain.
Charge status pin, open drain.
Charge termination current programming input pin (internal default 10%
termination current if TERM is open).
Ground.
Charge timer programming input pin (no timer if grounded).
Input supply power-good status pin, open drain.
Charge status pin, open drain.
Battery temperature sense pin. (Leave this TS pin open to disable this
function in AAT3683-2).
Connect to Li-Ion battery.
Input from USB port/AC adapter connector.
Charge current programming input pin.
Active high enable pin (with internal pull-down).
Not connected.
Exposed paddle (bottom); connect to ground as closely as possible to the
device.
EP
Pin Configuration
AAT3683-2
STDFN2.2x2.2-10
(Top View)
AAT3683-4
QFN33-16
(Top View)
8
4
7
5
6
13
3
N/C
9
14
2
EN
ISET
IN
BAT
TS
N/C
10
15
16
N/C
1
12
EN
TERM
2
11
ISET
GND
3
10
N/C
CT
4
9
N/C
5
6
7
8
STAT2
BAT
TS
N/C
2
1
IN
STAT1
STAT
TERM
GND
CT
ADPP#
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com
201885B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 25, 2012
DATA SHEET
AAT3683
1A Linear Li-Ion Battery Charger
AAT3683 Feature Options
Product
Battery Temperature Sense
Status Indicator Display
AAT3683-2
AAT3683-4
For Use With 10k NTC Thermistor
For Use With Any Thermistor
1 LED
2 LEDs
Absolute Maximum Ratings1
Symbol
VIN
VN
TJ
TLEAD
TA
Description
Value
IN Continuous
BAT, STAT, ADPP#, EN, ISET, TS, STAT1, STAT2
Junction Temperature Range
Maximum Soldering Temperature (at Leads)
Operating Temperature Range
Units
-0.3 to 8.0
-0.3 to VIN + 0.3
-40 to 150
300
-40 to 85
V
°C
Thermal Information2
Symbol
Description
JA
Thermal Resistance
PD
Maximum Power Dissipation (TA = 25°C)
STDFN2.2x2.2-10
QFN33-16
STDFN2.2x2.2-10
QFN33-16
Value
Units
50
°C/W
2
W
1. Stresses above those listed in Absolute Maximum Ratings may cause permanent damage to the device. Functional operation at conditions other than the operating conditions
specified is not implied.
2. Mounted on an FR4 board.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com
201885B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 25, 2012
3
DATA SHEET
AAT3683
1A Linear Li-Ion Battery Charger
Electrical Characteristics
VIN = 5V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = 25°C.
Symbol
Description
Operation
Input Voltage Range
VIN
Under-Voltage Lockout Threshold
VUVLO
UVLO Hysteresis
Adapter Present Indicator Threshold
VADPP_TH
Voltage, VIN - VBA
IOP
Operating Current
ISHUTDOWN Shutdown Current
Leakage Current from BAT Pin
ILEAKAGE
Voltage Regulation
VBAT_EOC
End of Charge Accuracy
VBAT_EOC/
End of Charge Tolerance
VBAT_EOC
VMIN
Preconditioning Voltage Threshold
VRCH
Trickle-Charge Current
ICH_TERM
Charge Termination Threshold Current
Charging Devices
RDS(ON)
Charging Transistor On Resistance
4
Rising Edge
Min
Typ
4.0
3
Max
Units
7.5
4
V
150
VIN > VUVLO
60
Charge Current = 100mA
VBAT = 4.25V, EN = GND
VBAT = 4V, IN Pin Open
0.3
0.4
4.158
4.20
110
1
2
4.242
0.5
(Option available for no trickle charge)
2.5
Battery Recharge Voltage Threshold
Current Regulation
ICC_RANGE
Charge Current Programmable Range
ICH_CC
Constant Current Mode Charge Current
VISET
ISET Pin Voltage
KISET
Charge Current Set Factor: ICH_CC/IISET
VTERM
TERM Pin Voltage
ICH_TRK
Conditions
VIN = 6.5V and VBAT = 3.6V
100
-12.5
VIN = 5V
5
8
0.5
V
V
mA
%
V
V
15
% ICH_CC
12
%
0.7

Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com
201885B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 25, 2012
μA
2.7
1000
12.5
10
mA
%
2
800
0.2
Constant Current Mode, VBAT = 3.6V
RTERM = 13.3K
TERM Pin Open
RTERM = 13.3K, ICH_CC  800mA
2.6
VBAT_EOC
- 0.1
mV
DATA SHEET
AAT3683
1A Linear Li-Ion Battery Charger
Electrical Characteristics
VIN = 5V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = 25°C.
Symbol
Description
Logic Control / Protection
VEN(H)
Input High Threshold
VEN(L)
Input Low Threshold
VSTAT
Output Low Voltage
ISTAT
STAT Pin Current Sink Capability
VADDP#
Output Low Voltage
ADDP# Pin Current Sink Capability
IADPP#
VOVP
Over-Voltage Protection Threshold
IOCP
Over-Current Protection Threshold
TK
Trickle Timeout
TC
Trickle and Constant Current Mode Timeout
TV
Constant Voltage Mode Timeout
Current Source from TS Pin
ITS
TS1
TS Hot Temperature Fault
TS2
TS Cold Temperature Fault
VTS1
VTS2
High Temperature Threshold
Low Temperature Threshold
Thermal Loop Entering Threshold
Thermal Loop Exiting Threshold
Thermal Loop Regulation
TLOOP_IN
TLOOP_OUT
TREG
TSHDN
Over-Temperature Shutdown
Conditions
Min
Typ
Max
Units
0.4
0.2
8
0.2
8
V
1.6
STAT Pin Sinks 4mA
4.4
105
25
mA
V
mA
V
%ICH_CC
Minute
3
Hour
ADPP# Pin Sinks 4mA
CT = 0.1μF, VIN = 5V
AAT3683-2 Only
Threshold, AAT3683-2 Only
Hysteresis, AAT3683-2 Only
Threshold, AAT3683-2 Only
Hysteresis, AAT3683-2 Only
AAT3683-4 Only
Threshold
Hysteresis
69
316
2.30
29.1
58.2
75
331
25
2.39
25
30
60
115
85
100
140
15
81
346
2.48
30.9
61.8
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com
201885B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 25, 2012
μA
mV
V
mV
%VIN
ºC
5
DATA SHEET
AAT3683
1A Linear Li-Ion Battery Charger
Typical Characteristics
Charging Current vs. Battery Voltage
1200
10000
RSET = 1.58k
1000
1000
ICH (mA)
CC Mode Charge Current (mA)
Constant Charging Current
vs. Set Resistor Values
100
RSET = 2k
800
600
RSET = 3.24k
400
RSET = 8.06k
200
0
2.5
10
1
10
100
2.7
2.9
3.1
3.3
RSET (kΩ
Ω)
3.5
3.7
3.9
4.1
4.3
VBAT (V)
End of Charge Regulation Accuracy
vs. Input Voltage
End of Charge Voltage vs. Temperature
(VBAT_EOC = 4.2V)
4.220
0.15
4.210
0.10
VEOC (V)
ΔVBAT_EOC/VBAT_EOC (%)
0.20
0.05
0.00
-0.05
4.200
4.190
-0.10
-0.15
-0.20
4.5
5.0
5.5
6.0
6.5
7.0
4.180
-50
7.5
-25
Preconditioning Charge Current
vs. Input Voltage
50
75
100
Preconditioning Voltage Threshold
vs. Temperature
120
2.7
RSET = 1.58k
100
2.65
RSET = 2k
80
60
2.6
VMIN (V)
ICH_TRK (mA)
25
Temperature (°°C)
Input Voltage (V)
RSET = 3.24k
40
2.55
2.5
RSET = 8.06k
20
2.45
0
4
4.5
5
5.5
6
Input Voltage (V)
6
0
6.5
7
7.5
2.4
-40
-15
10
35
Temperature (°°C)
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com
201885B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 25, 2012
60
85
DATA SHEET
AAT3683
1A Linear Li-Ion Battery Charger
Typical Characteristics
Preconditioning Charge Current vs. Temperature
Battery Recharge Voltage
Threshold vs. Temperature
(RSET = 8.06k; ICH_CC = 200mA)
Preconditioning
Charge Current (mA)
23
4.14
22
4.12
VRCH (V)
21
20
19
4.10
4.08
4.06
18
4.04
17
-40
-15
10
35
60
-40
85
-15
Temperature (°°C)
35
60
85
Temperature (°°C)
Constant Charging Current vs. Input Voltage
Temperature Sense Output Current
vs. Temperature (AAT3683-2 Only)
(RSET = 1.58KΩ
Ω)
78.0
1100
VBAT = 3.3V
1050
76.0
1000
950
ITS (µA)
Constant Charging Current (mA)
10
VBAT = 3.5V
900
850
74.0
72.0
VBAT = 3.9V
800
70.0
750
700
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
68.0
-40
-15
0.345
0.340
0.335
0.330
0.325
10
35
Temperature (°°C)
60
85
Temperature Sense Too Cold Threshold
vs. Temperature (AAT3683-2 Only)
Temperature Sense
Threshold Voltage- TS2 (V)
Temperature Sense
Threshold Voltage - TS1 (V)
Temperature Sense Too Hot Threshold
vs. Temperature (AAT3683-2 Only)
-15
35
Temperature (°°C)
Input Voltage (V)
0.320
-40
10
60
85
2.42
2.41
2.40
2.39
2.38
2.37
-40
-15
10
35
60
85
Temperature (°°C)
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com
201885B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 25, 2012
7
DATA SHEET
AAT3683
1A Linear Li-Ion Battery Charger
Typical Characteristics
Operating Current vs. ISET Resistor
Shutdown Current vs. Input Voltage
1.4
1.6
1.4
1.2
IOP (mA)
ISHUTDOWN (µA)
Constant Current Mode
1.2
1.0
Preconditioning Mode
0.8
0.6
0.4
85°C
1.0
0.8
25°C
0.6
-40°C
0.4
0.2
0.2
0.0
0.0
1
10
100
4
1000
4.5
5
RSET (kΩ
Ω)
6.5
7
7.5
CT Pin Capacitance vs. Counter Timeout
1.0
0.10
Capacitance (µF)
0.9
0.05
0.00
-0.05
0.8
0.7
Preconditioning Timeout
0.6
0.5
0.4
0.3
Preconditioning + Constant Current
Timeout or Constant Voltage Timeout
0.2
0.1
0.0
-0.10
-40
-15
10
35
60
0
85
1
Temperature (°°C)
2
3
4
5
Time (hours)
Termination Current to Constant Current Ratio (%)
vs. Termination Resistance
Charging Transistor On Resistance
vs. Supply Voltage
50%
800
750
85°C
40%
700
RDS(ON) (mΩ
Ω)
ICH_TERM/ICH_CC (%)
6
Input Voltage (V)
Counter Timeout vs. Temperature
(CT = 0.1µF)
Counter Timeout (%)
5.5
30%
20%
650
600
550
500
10%
25°C
450
0%
0
10
20
30
40
ITERM Resistance (kΩ
Ω)
8
50
60
400
3.6
3.9
4.2
4.5
VIN (V)
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201885B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 25, 2012
4.8
5.1
DATA SHEET
AAT3683
1A Linear Li-Ion Battery Charger
Typical Characteristics
Input High Threshold vs. Input Voltage
Input Low Threshold vs. Input Voltage
1.5
1.2
1.4
1.1
1.3
VEN(L) (V)
VEN(H) (V)
-40°C
1.0
1.2
-40°C
1.1
1.0
0.9
0.8
25°C
85°C
0.9
0.8
25°C
0.7
85°C
0.6
0.7
0.5
0.6
0.4
0.5
4.0
4.5
5.0
5.5
6.0
Input Voltage (V)
6.5
7.0
7.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
Input Voltage (V)
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201885B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 25, 2012
9
DATA SHEET
AAT3683
1A Linear Li-Ion Battery Charger
Functional Block Diagram
Reverse Blocking
IN
BAT
Current
Compare
ADPP#
Charge
Control
Constant
Current
ISET
(3683-2 only)
CV/ Precharge
OverTemp.
Protect
Power
Detection
Charge
Status
TS
IC Enable
Window
Comparator
EN
CT
The AAT3683 is a high performance battery charger
designed to charge single-cell lithium-ion or lithiumpolymer batteries with up to 1A of current from an external 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.
is rated for operation from -40°C to
event of operating ambient temperatures
power dissipation abilities of the device
given constant current charge level, the
will enter into thermal limit.
AAT3683-2 provides one status monitor output pin
(STAT) by directly driving one external LED to indicate
STAT (3683-2 only)
STAT1 (3683-4 only)
STAT2 (3683-4 only)
Watchdog
Timer
Functional Description
10
Battery OV
Protection
Thermal
Loop
75μA
(3683-2 only)
The AAT3683
+85°C. In the
exceeding the
package for a
charge control
UVLO
GND
the battery charging state. AAT3683-4 provides two status pins to indicate the battery charging state.
Device junction temperature and charge state are fully
monitored for fault conditions. In the event of an overvoltage or over-temperature failure, the device will automatically 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 temperature or excessive power dissipation condition, the
AAT3683 enables a digitally controlled thermal loop system 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 dissipation and ambient temperature conditions.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com
201885B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 25, 2012
DATA SHEET
AAT3683
1A Linear Li-Ion Battery Charger
The digital thermal loop control is dynamic in the sense
that it will continue to adjust the battery charging current as operating conditions change.
The digital thermal loop will reset and resume normal
operation when the power dissipation or over-temperature conditions are removed.
Battery Charging Operation
Figure 1 illustrates the entire battery charging profile or
operation, which consists of three phases:
1.
2.
3.
Preconditioning (Trickle) Charge
Constant Current Charge
Constant Voltage Charge
Battery Preconditioning
Battery charging commences only after the AAT3683
checks several conditions in order to maintain a safe
charging environment. The input supply must be above
the minimum operating voltage (VUVLO) and the enable
pin must be high. When the battery is connected to the
BAT pin, the AAT3683 checks the condition of the battery and determines which charging mode to apply. If
the battery voltage is below the preconditioning voltage
threshold, VMIN, then the AAT3683 begins preconditioning the battery cell (trickle charging) by charging at
Preconditioning
Trickle Charge
Phase
10% of the programmed constant current. For example,
if the programmed current is 500mA, then the preconditioning mode (trickle charge) current is 50mA. Battery
cell preconditioning (trickle charging) is a safety precaution for deeply discharged cells and will also reduce the
power dissipation in the internal series pass MOSFET
when the input-output voltage differential is at the
greatest potential.
Constant Current Charging
Battery cell preconditioning continues until the battery
voltage reaches the preconditioning voltage threshold,
VMIN. At this point, the AAT3683 begins constant current
charging. The current level for this mode is programmed
using a single resistor from the ISET pin to ground.
Programmed current can be set at a minimum 100mA up
to a maximum of 1A.
Constant Voltage Charging
Constant current charging will continue until such time
that the battery voltage reaches the voltage regulation
point, VBAT_EOC. When the battery voltage reaches VBAT_EOC,
the AAT3683 will transition to constant voltage mode.
The regulation voltage is factory programmed to a nominal 4.2V and will continue charging until the charge
termination current is reached.
Constant Current
Charge Phase
Constant Voltage
Charge Phase
Charge Complete Voltage
I = Max CC
Regulated Current
Constant Current Mode
Voltage Threshold
Trickle Charge and
Termination Threshold
I = CC / 10
Figure 1: Current vs. Voltage Profile During Charging Phases.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com
201885B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 25, 2012
11
DATA SHEET
AAT3683
1A Linear Li-Ion Battery Charger
System Operation Flow Chart
Enable
No
Power On Reset
Yes
Power Input
Voltage
VIN > VUVLO
Enable
Yes
Shut Down
Yes
Fault
Conditions Monitoring
OV, OT,
TS>VTS2 or TS<VTS1
Expired
Charge Timer
Control
No
Preconditioning
Test
VMIN > VBAT
Yes
Preconditioning
(Trickle Charge)
Thermal
Loop
Thermal
Loop
Current
Current
ReductionininADP
Reduction
C.C. ModeMode
Charging
Yes
No
No
No
Recharge Test
VRCH > VBAT
Yes
Current Phase Test
VIN > VBAT_EOC
Yes
Constant
Current Charge
Mode
Yes
Constant
Voltage Charge
Mode
Device Thermal
Loop Monitor
TJ > 115°C
No
Voltage Phase Test
IBAT > ITERM
No
Charge Completed
12
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com
201885B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 25, 2012
DATA SHEET
AAT3683
1A Linear Li-Ion Battery Charger
Application Information
Adapter or USB Power Input
Constant current charge levels up to 1A may be programmed by the user when powered from a sufficient
input power source. The AAT3683 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 RSET resistor connected between ISET and
ground. Refer to Table 4 for recommended RSET values
for a desired constant current charge level.
Adapter Input Charge Inhibit and Resume
The AAT3683 has a UVLO and power on reset feature so
that if the input supply to the ADP pin drops below the
UVLO threshold, the charger will suspend charging and
shut down. When power is re-applied 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.
Digital Thermal Loop Control
Due to the integrated nature of the linear charging control pass device for the adapter mode, a special thermal
loop control system has been employed to maximize
charging current under all operation conditions. The
thermal management system measures the internal circuit die temperature and reduces the fast charge current
when the device exceeds a preset internal temperature
control threshold. Once the thermal loop control becomes
active, the fast charge current is initially reduced by a
factor of 0.44.
The initial thermal loop current can be estimated by the
following equation:
ITLOOP = ICH_CC · 0.44
The thermal loop control re-evaluates the circuit die temperature every three seconds and adjusts the fast charge
current back up in small steps to the full fast charge current level or until an equilibrium current is discovered
and maximized for the given ambient temperature condition. The thermal loop controls the system charge level;
therefore, the AAT3683 will always provide the highest
level of constant current in the fast charge mode possible
for any given ambient temperature condition.
Enable / Disable
The AAT3683 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, AAT3683
is enabled. When left open or pulled to a logic low level,
the AAT3683 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 programmed 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 resistor
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 1A may be set
by selecting the appropriate resistor value from Table 1.
Constant Charging
Current (mA)
Set Resistor
Value (k)
100
16.2
200
8.06
300
5.36
400
4.02
500
3.24
600
2.67
700
2.26
800
2
900
1.78
1000
1.58
Table 1: RSET Values.
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13
DATA SHEET
AAT3683
1A Linear Li-Ion Battery Charger
Charge Status Output
ICH_CC (mA)
10000
The AAT3683 provides battery charge status via a status
pin (AAT3683-4 provides battery charge status via two
status pins). This pin is internally connected to an
N-channel open-drain MOSFET, which can be used drive
an external LED. The status pin can indicate the following conditions (AAT3683-2):
1000
100
10
1
10
100
RSET (kΩ
Ω)
Figure 2: Constant Charging Current
vs. Set Resistor Values.
Programmable Charge
Termination Current
The charge termination current ICH_TERM can be programmed by connecting a resistor from TERM to GND:
ICH_TERM =
15µA · RTERM
· ICH_CC
2V
If the TERM pin is left open, the termination current will
set to 10% of the constant charging current as the
default value.
When the charge current drops to the defaulted 10% of
the programmed charge current level or programmed
terminated current in the constant voltage mode, the
device terminates charging and goes into a sleep state.
The charger will remain in this sleep state until the battery voltage decreases to a level below the battery
recharge voltage threshold (VRCH).
Consuming very low current in sleep state, the AAT3683
minimizes battery drain when it is not charging. This
feature is particularly useful in applications where the
input supply level may fall below the battery charge or
under-voltage lockout level. In such cases where the
AAT3683 input voltage drops, the device will enter sleep
state and automatically resume charging once the input
supply has recovered from the fault condition.
Event Description
STATUS
No battery charging activity
Battery charging via adapter or USB port
Charging completed
OFF
ON
OFF
Table 2: LED Status Indicator
(AAT3683-2).
The status pins can indicate the following conditions
(AAT3683-4):
Event Description
STAT1
STAT2
Charge enabled without battery
Battery charging
Charge completed
Fault
FLASH1
ON
FLASH1
OFF
ON
OFF
OFF
Table 3: LEDs Status Indicator
(AAT3683-4).
The LED should be biased with as little current as necessary to create reasonable illumination; therefore, a ballast resistor should be placed between the LED cathode
and the STAT pin. LED current consumption will add to
the overall thermal power budget for the device package, hence it is good to keep the LED drive current to a
minimum. 2mA should be sufficient to drive most lowcost green or red LEDs. It is not recommended to exceed
8mA for driving an individual status LED.
1. Flashing rate depends on output capacitance.
14
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DATA SHEET
AAT3683
1A Linear Li-Ion Battery Charger
The required ballast resistor values can be estimated
using the following formula:
RBALLAST =
VIN - VF(LED)
ILED
Example:
RBALLAST =
5.0V - 2.0V
= 1.5kΩ
2mA
Note: Red LED forward voltage VF is typically 2.0V @
2mA.
Protection Circuitry
Programmable Watchdog Timer
The AAT3683 contains a watchdog timing circuit to shut
down charging functions in the event of a defective battery cell not accepting a charge over a preset period of
time. Typically, a 0.1μF ceramic capacitor is connected
between the CT pin and ground. When a 0.1μF ceramic
capacitor is used, the device will time out a shutdown
condition if the trickle charge mode exceeds 25 minutes
and a combined trickle charge plus constant current
mode of 3 hours. When the device transitions to the
constant voltage mode, the timing counter is reset and
will time out after an additional 3 hours if the charge
current does not drop to the charge termination level.
The 3683-4 has a battery fault detector, which, when
used in conjunction with a 0.1μF capacitor on the CT pin,
outputs a 1Hz signal with 50% duty cycle at the STAT1
pin in the event of a timeout while in the trickle charge
mode.
Mode
Time
Trickle Charge (TC) Time Out
Trickle Charge (TC) + Constant Current
(CC) Mode Time Out
Constant Voltage (VC) Mode Time Out
25 minutes
3 hours
Table 4: Summary for a 0.1μF Ceramic Capacitor
Used for the Timing Capacitor.
The CT pin is driven by a constant current source and
will provide a linear response to increases in the timing
capacitor value. Thus, if the timing capacitor were to be
doubled from the nominal 0.1μF value, the time-out
periods would be doubled.
If the programmable watchdog timer function is not
needed, it can be disabled by terminating the CT pin to
ground. The CT pin should not be left floating or unterminated, as this will cause errors in the internal timing control circuit.
The constant current provided to charge the timing
capacitor is very small, and this pin is susceptible to
noise and changes in capacitance value. Therefore, the
timing capacitor should be physically located on the
printed circuit board layout as close as possible to the CT
pin. Since the accuracy of the internal timer is dominated by the capacitance value, a 10% tolerance or better ceramic capacitor is recommended. Ceramic capacitor materials, such as X7R and X5R types, are a good
choice for this application.
Over-Voltage Protection
An over-voltage event is defined as a condition where
the voltage on the BAT pin exceeds the maximum battery charge voltage and is set by the over-voltage protection threshold (VOVP). If an over-voltage condition
occurs, the AAT3683 charge control will shut down the
device until the voltage on the BAT pin drops below VOVP.
The AAT3683 will resume normal charging operation
after the over-voltage condition is removed. During an
over-voltage event, the STAT LEDs (3683-4 only) will
report a system fault.
Over-Temperature Shutdown
The AAT3683 has a thermal protection control circuit
which will shut down charging functions should the internal die temperature exceed the preset thermal limit
threshold. Once the internal die temperature falls below
the thermal limit, normal operation will resume the previous charging state.
Battery Temperature Fault Monitoring
In the event of a battery over-temperature condition,
the charge control will turn off the internal pass device
and report a battery temperature fault on the STAT pins.
After the system recovers from a temperature fault, the
device will resume charging operation.
The AAT3683-2 checks battery temperature before
starting the charge cycle, as well as during all stages of
charging. This is accomplished by monitoring the voltage
at the TS pin. This system is intended for use with
negative temperature coefficient thermistors (NTC)
which are typically integrated into the battery package.
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15
DATA SHEET
AAT3683
1A Linear Li-Ion Battery Charger
Most of the commonly used NTC thermistors in battery
packs are approximately 10k at room temperature
(25°C). The TS pin (3683-2 only) has been specifically
designed to source 75μA of current to the thermistor.
The voltage on the TS pin resulting from the resistive
load should stay within a window of 331mV to 2.39V. If
the battery becomes too hot during charging due to an
internal fault or excessive constant charge current, the
thermistor will heat up and reduce in value, pulling the
TS pin voltage lower than the TS1 threshold, and the
AAT3683-2 will stop charging until the condition is
removed, when charging will be resumed.
If the use of the TS pin function is not required by the
system, it should be terminated to ground using a 10k
resistor. Alternatively, on the AAT3683-2 only, the TS pin
may be left open.
For AAT3683-4, the internal battery temperature sensing
system is comprised of two comparators which establish
a voltage window for safe operation. The thresholds for
the TS operating window are bounded by the TS1 and
TS2 specifications. Referring to the electrical characteristics table in this datasheet, the TS1 threshold = 0.30 · VIN
and the TS2 threshold = 0.60 · VIN. If the use of the TS
pin function is not required on AAT3683-4, the TS pin
should be connected to input supply VIN.
power dissipation when properly bonded to a printed
circuit board and have a maximum thermal resistance of
50°C/W. Many considerations should be taken into
account when designing the printed circuit board layout,
as well as the placement of the charger IC package in
proximity to other heat generating devices in a given
application design. The ambient temperature around the
charger IC will also have an effect on the thermal limits
of a battery charging application. The maximum limits
that can be expected for a given ambient condition can
be estimated by the following discussion.
First, the maximum power dissipation for a given situation should be calculated:
PD(MAX) =
TJ - TA
ΘJA
Where:
PD(MAX)
JA
TJ
TA
=
=
=
=
Maximum Power Dissipation (W)
Package Thermal Resistance (°C/W)
Thermal Loop Entering Threshold (ºC) [115ºC]
Ambient Temperature (°C)
Figure 4 shows the relationship of maximum power dissipation and ambient temperature of AAT3683.
2.5
VIN
IN
PD(MAX) (W)
2
AAT3683-4
0.60x VIN
1.5
1
0.5
Battery Cold Fault
TS
0
0
25
50
75
100
TA (°°C)
Battery
Pack
Figure 4: Maximum Power Dissipation Before
Entering Thermal Loop.
Battery Hot Fault
x V IN
Next, the power dissipation can be calculated by the following equation:
PD = (VIN - VBAT) · ICH + VIN · IOP
Figure 3: AAT3683-4 Battery Temperature Sense
Circuit.
Thermal Considerations
The AAT3683 is offered in two packages (STDFN2.2x2.2-10
and QFN33-16) both of which can provide up to 2W of
16
Where:
PD
VIN
VBAT
ICH
IOP
=
=
=
=
Total Power Dissipation by the Device
Input Voltage
Battery Voltage as Seen at the BAT Pin
Constant Charge Current Programmed for the
Application
= Quiescent Current Consumed by the Charger IC
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DATA SHEET
AAT3683
1A Linear Li-Ion Battery Charger
Capacitor Selection
for Normal Operation [0.3mA]
By substitution, we can derive the maximum charge current before reaching the thermal limit condition (thermal
loop). The maximum charge current is the key factor
when designing battery charger applications.
ICH(MAX) =
PD(MAX) - VIN · IOP
VIN - VBAT
TJ - TA - V · I
IN
OP
ΘJA
ICH(MAX) =
VIN - VBAT
In general, the worst condition is the greatest voltage
drop across the charger IC, when battery voltage is
charged up to the preconditioning voltage threshold and
before entering thermal loop regulation. Figure 5 shows
the maximum charge current in different ambient temperatures.
1000
ICC_MAX (mA)
800
TA = 45°C
TA = 25°C
600
400
200
TA = 85°C
0
4.25
4.5
4.75
TA = 60°C
5
5.25
5.5
5.75
6
6.25
6.5
6.75
7
VIN (V)
Figure 5: Maximum Charging Current Before the
Digital Thermal Loop Becomes Active.
Input Capacitor
In general, it is good design practice to place a decoupling capacitor between the IN pin and GND. An input
capacitor in the range of 1μF to 22μF is recommended.
If the source supply is unregulated, it may be necessary
to increase the capacitance to keep the input voltage
above the under-voltage lockout threshold during device
enable and when battery charging is initiated. If the
AAT3683 adapter input is to be used in a system with an
external power supply source, such as a typical AC-toDC wall adapter, then a CIN capacitor in the range of
10μF should be used. A larger input capacitor in this
application will minimize switching or power transient
effects when the power supply is “hot plugged” in.
Output Capacitor
The AAT3683 only requires a 1μF ceramic capacitor on
the BAT pin to maintain circuit stability. This value should
be increased to 10μF or more if the battery connection
is made any distance from the charger output. If the
AAT3683 is to be used in applications where the battery
can be removed from the charger, such as with desktop
charging cradles, an output capacitor greater than 10μF
may be required to prevent the device from cycling on
and off when no battery is present.
Printed Circuit Board
Layout Considerations
For the best results, it is recommended to physically
place the battery pack as close as possible to the
AAT3683 BAT pin. To minimize voltage drops on the PCB,
keep the high current carrying traces adequately wide.
When designing with >500mA charging current system,
a multilayer PCB design is highly recommended. Putting
thermal vias on the thermal pad design will effectively
transfer heat from the top metal layer of the PCB to the
inner or bottom layers. The number of thermal vias will
depend on the application and power dissipation. Refer
to the AAT3683 evaluation board for a good layout
example.
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17
DATA SHEET
AAT3683
1A Linear Li-Ion Battery Charger
Figure 6: AAT3683-2 Evaluation Board
Top Side Layout.
Figure 7: AAT3683-2 Evaluation Board
Middle Layer.
Figure 8: AAT3683-2 Evaluation Board
Bottom Side Layout.
VIN
JP2
D1
GRN
LED
D2
RED
LED
R4
1.5k
VBAT
Enable
STDFN2.2x2.2-10
R3 1.5k
1
2
3
4
5
R2
13.3k
C3
0.1μF
STAT
EN
TERM ISET
GND
IN
CT
BAT
ADPP# TS
U1 AAT3683-2
JP1
10
9
8
7
6
R5 R1
10K 1.58k
C2
10μF
C1
10μF
Figure 9: AAT3683-2 Evaluation Board Schematic.
18
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DATA SHEET
AAT3683
1A Linear Li-Ion Battery Charger
Figure 10: AAT3683-4 Evaluation Board
Top Side Layout.
Figure 11: AAT3683-4 Evaluation Board
Middle Layer.
Figure 12: AAT3683-4 Evaluation Board Bottom Side Layout.
VIN
JP2
D1
JP1
R3 1.5k
N/C
TERM
GND
CT
STAT2
BAT
TS
N/C
R2
13.3k
1
2
3
4
STAT1
IN
N/C
N/C
AAT3683-4
U1 16 15 14 13 QFN33-16
GRN LED
C3
0.1μF
EN
ISET
N/C
N/C
12
11
10
9
Enable
R5
10K
R1
1.58k
5 6 7 8
D2
R6
10K
R4
VBAT
1.5k
RED LED
C2
10μF
Figure 13: AAT3683-4 Evaluation Board Schematic.
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19
DATA SHEET
AAT3683
1A Linear Li-Ion Battery Charger
Component
U1
R1
R2
R3, R4
R5
C1, C2
C3
JP1
D1
D2
Part Number
Description
AAT3683IOQ-4.2-2
1A Linear Li-Ion Battery Charger, 2.2x2.2mm STDFN-10 Package
1.58KΩ, 1%, 1/4W 0603
13.3KΩ, 1%, 1/4W 0603
1.5KΩ, 5%, 1/4W 0402
10KΩ, 1%, 1/4W 0603
CER 10μF 6.3V 10% X5R 0603
CER 0.1μF 6.3V 10% X7R 0603
Conn. Header, 2mm zip
Green LED 1206
Red LED 1206
Chip Resistor
ECJ-1VB0J106M
GRM188R71C104KA01
PRPN401PAEN
CMD15-21VGC/TR8
CMD15-21SRC/TR8
Manufacturer
Skyworks
Vishay
Panansonic
Murata
Sullins Electronics
Chicago Miniature Lamp
Table 5: AAT3683-2 Evaluation Board Bill of Materials.
Component
U1
R1
R2
R3, R4
R5, R6
C1, C2
C3
JP1
D1
D2
Part#
Description
AAT3683IVN-4.2-4
1A Linear Li-Ion Battery Charger, QFN33-16 Package
1.58KΩ, 1%, 1/4W 0603
13.3KΩ, 1%, 1/4W 0603
1.5KΩ, 5%, 1/4W 0402
10KΩ, 1%, 1/4W 0603
CER 10μF 10V 10% X5R 0805
CER 0.1μF 6.3V 10% X7R 0603
Conn. Header, 2mm zip
Green LED 1206
Red LED 1206
Chip Resistor
GRM21BR61A106KE19
GRM188R71C104KA01
PRPN401PAEN
CMD15-21VGC/TR8
CMD15-21SRC/TR8
Manufacturer
Skyworks
Vishay
Murata
Sullins Electronics
Chicago Miniature Lamp
Table 6: AAT3683-4 Evaluation Board Bill of Materials.
20
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DATA SHEET
AAT3683
1A Linear Li-Ion Battery Charger
Ordering Information
Package
Marking1
Part Number (Tape and Reel)2
STDFN-10 (2.2x2.2mm)
QFN33-16
WIXYY
WKXYY
AAT3683IOQ-4.2-2-T1
AAT3683IVN-4.2-4-T1
Skyworks Green™ products are compliant with
all applicable legislation and are halogen-free.
For additional information, refer to Skyworks
Definition of Green™, document number
SQ04-0074.
Package Information3
STDFN2.2x2.2-10
2.200 ± 0.050
1.000 ± 0.050
Top View
Detail "A"
1.710 ± 0.050
2.200 ± 0.050
Index Area
Bottom View
0.400 BSC
0.025 ± 0.025
0.152 REF
0.550 ± 0.050
0.350 ± 0.050
Side View
0.210 ± 0.050
Pin 1 Indicator
(optional)
R0.200
Detail "A"
All dimensions in millimeters.
1. XYY = assembly and date code.
2. Sample stock is generally held on part numbers listed in BOLD.
3. The leadless package family, which includes QFN, TQFN, DFN, TDFN and STDFN, has exposed copper (unplated) at the end of the lead terminals due to the manufacturing
process. A solder fillet at the exposed copper edge cannot be guaranteed and is not required to ensure a proper bottom solder connection.
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21
DATA SHEET
AAT3683
1A Linear Li-Ion Battery Charger
QFN33-16
Pin 1 Dot By Marking
0.230 ± 0.050
Pin 1 Identification
0.500 ± 0.050
1.250 ± 0.050
5
C0.3
13
9
1.250 ± 0.050
Top View
0.025 ± 0.025
Bottom View
0.214 ± 0.036
0.900 ± 0.100
3.000 ± 0.050
0.400 ± 0.100
3.000 ± 0.050
1
Side View
All dimensions in millimeters.
Copyright © 2012 Skyworks Solutions, Inc. All Rights Reserved.
Information in this document is provided in connection with Skyworks Solutions, Inc. (“Skyworks”) products or services. These materials, including the information contained herein, are provided by Skyworks as a
service to its customers and may be used for informational purposes only by the customer. Skyworks assumes no responsibility for errors or omissions in these materials or the information contained herein. Skyworks may change its documentation, products, services, specifications or product descriptions at any time, without notice. Skyworks makes no commitment to update the materials or information and shall have no
responsibility whatsoever for conflicts, incompatibilities, or other difficulties arising from any future changes.
No license, whether express, implied, by estoppel or otherwise, is granted to any intellectual property rights by this document. Skyworks assumes no liability for any materials, products or information provided hereunder, including the sale, distribution, reproduction or use of Skyworks products, information or materials, except as may be provided in Skyworks Terms and Conditions of Sale.
THE MATERIALS, PRODUCTS AND INFORMATION ARE PROVIDED “AS IS” WITHOUT WARRANTY OF ANY KIND, WHETHER EXPRESS, IMPLIED, STATUTORY, OR OTHERWISE, INCLUDING FITNESS FOR A PARTICULAR
PURPOSE OR USE, MERCHANTABILITY, PERFORMANCE, QUALITY OR NON-INFRINGEMENT OF ANY INTELLECTUAL PROPERTY RIGHT; ALL SUCH WARRANTIES ARE HEREBY EXPRESSLY DISCLAIMED. SKYWORKS DOES
NOT WARRANT THE ACCURACY OR COMPLETENESS OF THE INFORMATION, TEXT, GRAPHICS OR OTHER ITEMS CONTAINED WITHIN THESE MATERIALS. SKYWORKS SHALL NOT BE LIABLE FOR ANY DAMAGES, INCLUDING BUT NOT LIMITED TO ANY SPECIAL, INDIRECT, INCIDENTAL, STATUTORY, OR CONSEQUENTIAL DAMAGES, INCLUDING WITHOUT LIMITATION, LOST REVENUES OR LOST PROFITS THAT MAY RESULT FROM
THE USE OF THE MATERIALS OR INFORMATION, WHETHER OR NOT THE RECIPIENT OF MATERIALS HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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use or sale.
Customers are responsible for their products and applications using Skyworks products, which may deviate from published specifications as a result of design defects, errors, or operation of products outside of published parameters or design specifications. Customers should include design and operating safeguards to minimize these and other risks. Skyworks assumes no liability for applications assistance, customer product
design, or damage to any equipment resulting from the use of Skyworks products outside of stated published specifications or parameters.
Skyworks, the Skyworks symbol, and “Breakthrough Simplicity” are trademarks or registered trademarks of Skyworks Solutions, Inc., in the United States and other countries. Third-party brands and names are for
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22
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