Analogic AAT3689 0.5a/1.0a usb port/adapter lithium-ion/polymer battery charger Datasheet

AAT3689
0.5A/1.0A USB Port/Adapter
Lithium-Ion/Polymer Battery Charger
General Description
Features
The AAT3689 BatteryManager is a highly integrated single cell lithium-ion/polymer battery charger
IC designed to operate with USB port and AC
adapter inputs. It requires a minimum number of
external components.
•
•
•
The AAT3689 precisely regulates battery charge
voltage and current for 4.2V lithium-ion/polymer battery cells. Adapter charge current rates may be programmed up to 1.0A. In the absence of an adapter
and with a USB port connected, the battery can also
be charged by USB power. The USB charge current
can be programmed up to 500mA. USB charging is
disabled when an adapter is present.
•
•
•
•
•
•
•
•
•
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. Status monitor output pins are
provided to indicate the battery charge status by
directly driving two external LEDs.
BatteryManager™
USB/AC Adapter System Power Charger
— USB: Programmable up to 500mA
— Adapter: Programmable up to 1.0A
4.0V to 5.5V Input Voltage Range
Adapter Presence Automatically Disables
USB Charging
High Level of Integration With Internal:
— Charging Devices
— Reverse Blocking Diodes
— Current Sensing
Automatic Recharge Sequencing
Battery Temperature Monitoring
Full Battery Charge Auto Turn-Off
Over-Current Protection
Over-Voltage Protection
Emergency Thermal Protection
Power On Reset and Soft Start
12-Pin 3x3 TDFN Package
Applications
•
•
•
•
•
•
The AAT3689 is available in a Pb-free, thermallyenhanced, space-saving 12-pin 3x3mm TDFN
package and is rated over the -40°C to +85°C temperature range.
Cellular Telephones
Digital Still Cameras
Hand-Held PCs
MP3 Players
Personal Data Assistants (PDAs)
Other Lithium-Ion/Polymer Battery-Powered
Devices
Typical Application
Enable
EN
USB Input
BATT+
USB
BAT
USBSET
TS
C2
10μF
RSETUSB
AAT3689
BATTCT
CT
ADP Input
ADP
GND
ADPSET
RSETADP
STAT1
TEMP
STAT2
Battery Pack
3689.2006.11.1.0
1
AAT3689
0.5A/1.0A USB Port/Adapter
Lithium-Ion/Polymer Battery Charger
Pin Descriptions
Pin #
Name
Type
1, 10
2
3
4
5
6
7
8
9
USB
BAT
ADP
GND
EN
TS
STAT2
STAT1
CT
In
In/Out
In
Ground
In
In/Out
Out
Out
In/Out
11
USBSET
In/Out
12
ADPSET
In/Out
EP
Function
USB power supply input.
Battery charging and sensing.
Adapter power supply input.
Ground connection.
Enable pin. Logic high enables the IC.
Connect to 10kΩ NTC thermistor.
Battery charge status indicator pin to drive an LED: active low, open-drain.
Battery charge status indicator pin to drive an LED: active low, open-drain.
Timing capacitor to adjust internal watchdog timer. Set maximum charge
time for adapter powered trickle, CC, and CV charge modes. The watchdog
timer only sets the timers for adapter battery charging; there is no timeout
for the battery charging from the USB input. If timing function is not needed, terminate this pin to ground.
Connect a resistor between this pin and GND to set the USB charging
current.
Connect a resistor between this pin and GND to set the adapter charging
current.
Exposed paddle (bottom); connect to GND directly beneath package.
Pin Configuration
TDFN33-12
(Top View)
USB
BAT
ADP
GND
EN
TS
2
1
12
2
11
3
10
4
9
5
8
6
7
ADPSET
USBSET
USB
CT
STAT1
STAT2
3689.2006.11.1.0
AAT3689
0.5A/1.0A USB Port/Adapter
Lithium-Ion/Polymer Battery Charger
Absolute Maximum Ratings1
Symbol
VP
VP
VN
TJ
TLEAD
Description
USB, ADP, <30ms, Duty Cycle <10%
USB, ADP Continuous
BAT, USBSET, ADPSET, STAT1, STAT2, TS, CT, EN
Operating Junction Temperature Range
Maximum Soldering Temperature (at leads)
Value
Units
-0.3 to 7.0
-0.3 to 6.0
-0.3 to VP + 0.3
-40 to 150
300
V
V
V
°C
°C
Value
Units
50
2.0
°C/W
W
Thermal Information2
Symbol
θJA
PD
Description
Maximum Thermal Resistance
Maximum Power Dissipation
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. Only one Absolute Maximum Rating should be applied at any one time.
2. Mounted on an FR4 board.
3689.2006.11.1.0
3
AAT3689
0.5A/1.0A USB Port/Adapter
Lithium-Ion/Polymer Battery Charger
Electrical Characteristics1
VADP = 5V, TA = -25°C to +85°C, unless otherwise noted. Typical values are TA = 25°C.
Symbol
Description
Conditions
Min
Typ
Max Units
Operation
VUSB, VADP
VU_DSBL
VUVLO
IOP
ISLEEP
USB Port or Adapter Voltage
Range
ADP Voltage Level to Disable
USB Charging
Under-Voltage Lockout
Under-Voltage Lockout Hysteresis
Operating Current
Sleep Mode Current
Reverse Leakage Current from
BAT Pin
Voltage Regulation
VBAT_EOC1 End of Charge Voltage Accuracy
ΔVBAT/VBAT EOC Voltage Tolerance
VMIN
Preconditioning Voltage Threshold
Battery Recharge Voltage
VRCH
Threshold
Current Regulation
ICH
Charge Current
Charge Current Regulation
ΔICH/ICH
Tolerance
VADPSET
ADPSET Pin Voltage
VUSBSET
USBSET Pin Voltage
KIADP
Current Set Factor: ICHARGE/IADPSET
KIUSB
Current Set Factor: ICHARGE/IUSBSET
Charging Devices
Adapter Charging Transistor
RDS(ON)A
On Resistance
USB Charging Transistor
RDS(ON)U
On Resistance
ILeakage
4.0
4.25
Rising Edge
4.5
3.0
150
0.75
0.3
CC Charge Current = 500mA
VADP = 5V, USB = EN = GND
VUSB = 5V, ADP = EN = GND
VBAT = 4V, USB,
ADP Pins Open
5.5
V
4.7
V
1.5
1
12
1.0
4.158
2.8
4.2
0.5
3.0
In CC Mode
In CC Mode
μA
μA
4.242
3.15
VBAT_EOC - 0.1
100
V
mV
mA
V
%
V
V
1000
mA
10
%
2.0
2.0
4000
2000
V
V
VIN = 5.5V
0.2
0.25
0.35
Ω
VIN = 5.5V
0.4
0.5
0.65
Ω
1. The AAT3689 output charge voltage is specified over the 0° to 70°C ambient temperature range; operation over the -25°C to +85°C
temperature range is guaranteed by design.
4
3689.2006.11.1.0
AAT3689
0.5A/1.0A USB Port/Adapter
Lithium-Ion/Polymer Battery Charger
Electrical Characteristics1
VADP = 5V, TA = -25°C to +85°C, unless otherwise noted. Typical values are TA = 25°C.
Symbol
Description
Logic Control / Protection
Input High Threshold (Adapter)
VEN(H)
Input High Threshold (USB)
VEN(L)
Input Low Threshold
IEN(H)
EN Input Current
TP
Preconditioning Time Out (ADP mode only)
Preconditioning and Constant Current Mode
TC
Time Out (ADP mode only)
Constant Voltage Mode Time Out
TV
(ADP mode only)
VSTAT
Output Low Voltage
ISTAT
STAT Pin Current Sink Capability
VOVP
Over-Voltage Protection Threshold
ITK/ICH
Pre-Charge Current
IOCP
Over-Current Protection Threshold
ITERM/ICHG Charge Termination Threshold Current
ITS
Current Source from TS Pin
TS1
TS Hot Temperature Fault
TS2
TS Cold Temperature Fault
TOVSD
Over-Temperature Shutdown Threshold
Conditions
Min Typ Max
1.6
2.2
Units
V
0.4
10
VEN = 5V
CCT = 100nF, VADP = 5.5V
25
V
μA
Minute
CCT = 100nF, VADP = 5.5V
3.0
Hour
CCT = 100nF, VADP = 5.5V
3.0
Hour
STAT Pin Sinks 4mA
Threshold
Hysteresis
Threshold
Hysteresis
0.4
70
310
2.2
8.0
4.4
10
105
7.5
80
330
15
2.3
10
145
90
350
2.4
V
mA
V
%
%ICHG_CC
%
μA
mV
V
mV
°C
1. The AAT3689 output charge voltage is specified over the 0° to 70°C ambient temperature range; operation over the -25°C to +85°C
temperature range is guaranteed by design.
3689.2006.11.1.0
5
AAT3689
0.5A/1.0A USB Port/Adapter
Lithium-Ion/Polymer Battery Charger
Typical Characteristics
IFASTCHARGE vs. RSET
Battery Voltage vs. Supply Voltage
4.242
4.221
1000
VBAT (V)
IFASTCHARGE (mA)
10000
ADP
USB
4.200
ADP
USB
100
4.179
10
1
10
100
4.158
4.5
1000
4.75
RSET (kΩ
Ω)
5.0
5.25
5.5
Supply Voltage (V)
Battery Recharge Voltage Threshold
vs. Temperature
End of Charge Voltage vs. Temperature
4.242
4.140
4.130
4.120
VRCH (V)
VBAT_EOC (V)
4.221
4.110
ADP
4.100
4.090
USB
4.080
4.070
ADP
4.200
USB
4.179
4.060
4.050
4.040
-50
-25
0
25
50
75
4.158
-50
100
-25
0
Temperature (°°C)
25
50
75
100
Temperature (°°C)
Preconditioning Voltage Threshold
vs. Temperature
Preconditioning Charge Current vs. Temperature
(RSETADP = 8.06kΩ
Ω; RSETUSB = 8.06kΩ)
120
3.05
60
3.04
VMIN (V)
USB
3.01
3.00
2.99
ADP
2.98
2.97
110
55
ADP
100
50
USB
90
45
ICH USB (mA)
3.02
ICH ADP (mA)
3.03
2.96
80
2.95
-50
-25
0
25
50
Temperature (°°C)
6
75
100
-50
-25
0
25
50
75
40
100
Temperature (°C)
3689.2006.11.1.0
AAT3689
0.5A/1.0A USB Port/Adapter
Lithium-Ion/Polymer Battery Charger
Typical Characteristics
Fast Charge Current vs. Temperature
Adapter Charging Current vs. Battery Voltage
(RSETADP = 8.06kΩ
Ω; RSETUSB = 8.06kΩ)
1100
540
1080
530
500
1000
490
980
480
ADP
470
940
460
920
450
900
-50
-25
0
25
50
75
0.8
ICH (A)
510
1020
960
1.0
520
USB
1040
ICH USB (mA)
ICH ADP (mA)
1060
(RSETADP = 8.06kΩ
Ω)
1.2
0.6
0.4
0.2
0.0
440
100
2.5
2.9
3.3
Temperature (°C)
3.7
4.1
4.5
Battery Voltage (V)
USB Charging Current vs. Battery Voltage
(RSETUSB = 8.06kΩ
Ω)
Fast Charge Current vs. Adapter Supply Voltage
(RSETADP = 8.06kΩ
Ω)
600
1200
500
1000
400
800
ICH (mA)
ICH (mA)
VBAT = 3.3V
300
200
VBAT = 3.9V
600
VBAT = 3.5V
400
200
100
0
0
2.5
3.0
3.5
4.0
4.0
4.5
4.5
Battery Voltage (V)
Fast Charge Current vs. USB Supply Voltage
(RSETUSB = 8.06kΩ
Ω)
5.5
6.0
Fast Charge Current vs. USB Supply Voltage
(RSETUSB = 42.4kΩ
Ω)
120
600
VBAT = 3.5V
VBAT = 3.3V
100
500
VBAT = 3.5V
VBAT = 3.9V
400
300
VBAT = 3.9V
60
200
40
100
20
0
4.0
VBAT = 3.3V
80
ICH (mA)
ICH (mA)
5.0
Adapter Supply Voltage (V)
0
4.25
4.5
4.75
5.0
5.25
5.5
USB Supply Voltage (V)
3689.2006.11.1.0
5.75
6.0
4.0
4.5
5.0
5.5
6.0
6.5
USB Supply Voltage (V)
7
AAT3689
0.5A/1.0A USB Port/Adapter
Lithium-Ion/Polymer Battery Charger
Typical Characteristics
Fast Charge Current vs. USB Supply Voltage
VIH vs. Supply Voltage
(RSETUSB = 8.06kΩ
Ω)
EN Pin (Rising)
600
1.4
0°C
1.3
1.2
-40°C
1.1
70°C
400
VIH (V)
ICH (mA)
500
25°C
300
200
+25°C
1.0
0.9
0.8
0.7
+85°C
0.6
100
0.5
0.4
0
4.4
4.5
4.6
4.7
4.8
4.9
4.2
5.0
4.4
4.6
USB Supply Voltage (V)
5.0
5.2
5.4
5.6
5.8
6.0
Supply Voltage (V)
VIL vs. Supply Voltage
Adapter Mode Supply Current
vs. ADPSET Resistor
EN Pin (Falling)
1.4
0.80
1.3
0.70
1.2
0.60
1.1
-40°C
+25°C
IQ (mA)
VIH (V)
4.8
1.0
0.9
0.8
0.7
Constant Current
0.50
0.40
0.30
Pre-Conditioning
0.20
0.6
+85°C
0.10
0.5
0.00
0.4
4.2
4.4
4.6
4.8
5.0
5.2
5.4
5.6
5.8
1
6.0
10
100
1000
ADPSET Resistor (kΩ
Ω)
Supply Voltage (V)
Counter Timeout vs. Temperature
CT Pin Capacitance vs. Counter Timeout
10
2.0
8
1.8
6
1.6
Capacitance (μ
μF)
Counter Timeout (%)
(CT = 0.1µF)
4
2
0
-2
-4
-6
-8
1.2
1.0
0.8
Precondition + Constant Current Timeout
or Constant Voltage Timeout
0.6
0.4
0.2
-10
0.0
-50
-25
0
25
50
Temperature (°°C)
8
Precondition Timeout
1.4
75
100
0
2
4
6
8
10
Time (hours)
3689.2006.11.1.0
AAT3689
0.5A/1.0A USB Port/Adapter
Lithium-Ion/Polymer Battery Charger
Typical Characteristics
Temperature Sense Output Current
vs. Temperature
TS Pin Current (μA)
88
86
84
82
80
78
76
74
72
-50
-25
0
25
50
75
100
Temperature (°°C)
3689.2006.11.1.0
9
AAT3689
0.5A/1.0A USB Port/Adapter
Lithium-Ion/Polymer Battery Charger
Functional Block Diagram
Reverse Blocking
USB
Current
Compare
USBSET
CV/
Precharge
Charge
Control
Constant
Current
UVLO
OverTemperature
Protection
Current
Compare
ADPSET
BAT
ADP
Reverse Blocking
80uA
Voltage
Sense
STAT1
STAT2
TS
Window
Comparator
Charge
Status
IC Enable
Watchdog
Timer
CT
EN
GND
Functional Description
The AAT3689 is a highly integrated single cell lithium-ion/polymer battery charger IC designed to
operate with USB port and AC adapter inputs,
while requiring a minimum number of external
components. The AAT3689 precisely regulates
battery charge voltage and current for 4.2V lithiumion/polymer battery cells.
The adapter charge input constant current level
may be programmed up to 1.0A for rapid charging
applications. In the absence of a high current
adapter input source, the AAT3689 may be powered from a USB port VBUS supply. The USB constant charge current can be externally programmed for maximum constant current charge
levels up to 500mA. The USB charge function is
automatically disabled when an adapter input
power source greater than 4.5V is present.
10
Status monitor output pins are provided to indicate
the battery charge status by directly driving two
external LEDs.
Battery 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, thus protecting the charging device, control system, and the battery under
charge. In addition to internal charge controller thermal protection, the AAT3689 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.
Charging Operation
Regardless of which charge input function is selected (i.e., either the adapter input or USB input), the
AAT3689 has four basic modes for the battery
charge cycle: pre-conditioning/trickle charge; constant current/fast charge; constant voltage; and end
of charge (see Figure 1).
3689.2006.11.1.0
AAT3689
0.5A/1.0A USB Port/Adapter
Lithium-Ion/Polymer Battery Charger
Preconditioning
Trickle Charge
Phase
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.
Battery Preconditioning
Before the start of charging, the AAT3689 checks
several conditions in order to assure a safe charging
environment. The input supply must be above the
minimum operating voltage, or under-voltage lockout threshold (VUVLO), for the charging sequence to
begin. Also, the cell temperature, as reported by a
thermistor connected to the TS pin from the battery,
must be within the proper window for safe charging.
When these conditions have been met and a battery
is connected to the BAT pin, the AAT3689 checks
the state of the battery. If the cell voltage is below the
Preconditioning Voltage Threshold (VMIN), the
AAT3689 begins preconditioning the cell.
The battery preconditioning trickle charge current is
equal to the fast charge constant current divided by
10. For example, if the programmed fast charge current is 500mA, then the preconditioning mode (trickle charge) current will be 50mA. Cell preconditioning
is a safety precaution for a deeply discharged battery and also aids in limiting power dissipation in the
pass transistor when the voltage across the device
is at the greatest potential.
Fast Charge / Constant Current Charging
The cell preconditioning continues until the voltage
on the BAT pin exceeds the Preconditioning Voltage
Threshold (VMIN). At this point, the AAT3689 begins
the constant-current fast charging phase. The fast
charge Constant Current (ICC) amplitude is determined by the charge mode, ADP or USB, and is programmed by the user via the RSETADP and RSETUSB
resistors. The AAT3689 remains in constant current
3689.2006.11.1.0
charge mode until the battery reaches the voltage
regulation point, VBAT_EOC.
Constant Voltage Charging
The system transitions to a constant voltage charging mode when the battery voltage reaches output
charge regulation threshold (VBAT_EOC) during the
constant current fast charge phase. The regulation
voltage level is factory programmed to 4.2V (±1%).
The charge current in the constant voltage mode
drops as the battery cell under charge reaches its
maximum capacity.
End of Charge Cycle Termination and
Recharge Sequence
When the charge current drops to 7.5% of the programmed fast charge current level in the constant
voltage mode, the device terminates charging and
goes into a standby state. The charger will remain
in a standby state until the battery voltage decreases to a level below the battery recharge voltage
threshold (VRCH).
When the input supply is disconnected or drops
below UVLO or EN = 0, the charger will automatically enter power-saving sleep mode. Consuming an
ultra-low 0.3μA in sleep mode, the AAT3689 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
AAT3689 input voltage drops, the device will enter the
sleep mode and automatically resume charging once
the input supply has recovered from its fault condition.
11
AAT3689
0.5A/1.0A USB Port/Adapter
Lithium-Ion/Polymer Battery Charger
System Operation Flow Chart
ADP
Yes
Power Select
Yes
UVLO
VP > VUVLO
Switch
On
No
No
USB
Sleep
Mode
No
ADP
Loop
Power On
Reset
Enable
USB
Loop
Timing
Fault Conditions
Monitor
OV, OT
Yes
Shutdown
Mode
No
Yes
Battery
Temp. Monitor
VTS1 < TS < VTS2
No
Expire
Battery
Temp. Fault
Charge
Safety
Timer
No
Recharge Test
VRCH > VBAT
Yes
Preconditioning Test
VMIN > VBAT
Yes
Low Current
Conditioning
Charge
Yes
Current
Charging
Mode
Yes
Voltage
Charging
Mode
Set
No
Current Phase Test
VEOC > VBAT
No
Voltage Phase Test
IBAT > ITERM
No
Charge
Charge
Completed
Completed
12
3689.2006.11.1.0
AAT3689
0.5A/1.0A USB Port/Adapter
Lithium-Ion/Polymer Battery Charger
Application Information
AC Adapter / USB System Power Charging
Adapter Mode
In the adapter mode, constant current charge levels up to 1.0A may be programmed by the user.
The AAT3689 system control will always select the
adapter input over the USB supply input whenever
adapter voltage is present on the ADP pin. The
AAT3689 will operate from the adapter input over a
4.0V to 5.5V range.
The constant current fast charge current for the
adapter input mode is set by the RSETADP resistor
connected between the ADPSET pin and ground.
Refer to Table 1 for recommended RSETADP values
for a desired constant current charge level. The
precise charging function in the adapter mode may
be read from the status LEDs. Please refer to the
Battery Charge Status Indication discussion in this
datasheet for further details.
Adapter Input Charge Inhibit and Resume
The AAT3689 has an under-voltage lockout and
power on reset feature so that if the input supply to
the adapter pin drops below the UVLO threshold
the charger will suspend charging and shut down.
When power is re-applied to the adapter pin or the
UVLO condition recovers and VADP > VBAT, 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.
USB Mode
The AAT3689 provides an input for intelligent USB
charging. When no voltage is present on the
adapter input pin, the charge controller will automatically switch to accepting power from the USB
input. The USB charge may be user programmed
to any level between 50mA and 500mA by selecting the appropriate resistor values for RSETUSB.
Refer to Table 1 for recommended RSETUSB values
for the desired USB input constant current charge
levels.
3689.2006.11.1.0
ICC
ADP
Ω)
RSET (kΩ
USB
Ω)
RSET (kΩ
50
75
100
200
300
400
500
600
700
800
900
1000
N/A
N/A
84.5
43.2
28.0
21.0
16.9
13.3
11.5
10.2
9.09
8.06
86.6
57.6
42.2
21.0
13.7
10.2
8.06
N/A
N/A
N/A
N/A
N/A
Table 1: Resistor Values.
USB Input Charge Inhibit and Resume
The AAT3689 UVLO and power on reset feature
will function when the USB input pin voltage level
drops below the UVLO threshold. At this point, the
charger will suspend charging and shut down.
When power is re-applied to the USB 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 AAT3689 provides an enable function to control the charger IC on and off. The enable (EN) pin
is active high. When pulled to a logic low level, the
AAT3689 will be shut down and forced into the
sleep state. 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.
Programming Charge Current
The fast charge constant current charge level for
both Adapter and USB input modes are programmed with set resistors placed between the
ADPSET and USBSET pins and ground. The accuracy of the fast charge is dominated by the tolerance of the set resistor used. For this reason, 1%
13
AAT3689
0.5A/1.0A USB Port/Adapter
Lithium-Ion/Polymer Battery Charger
tolerance metal film resistors are recommended for
the set resistor function.
ADP fast charge constant current levels from 100mA
to 1.0A may be set by selecting the appropriate
resistor value from Table 1.
The USB charge may be set to any level between
50mA and 500mA depending upon the system
design requirements for a given USB charge application. Refer to Table 1 and Figure 2 for recommended RSETUSB values.
IFASTCHARGE (mA)
10000
1000
ADP
USB
100
10
1
10
100
1000
RSET (kΩ
Ω)
Figure 2: IFASTCHARGE vs. RSET.
Protection Circuitry
Programmable Watchdog Timer
The AAT3689 contains a watchdog timing circuit for
the adapter input charging mode. No watchdog timing functions are active for the USB input mode.
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 a
shutdown condition if the trickle charge mode
exceeds 25 minutes or the combined trickle charge
plus fast charge mode exceeds three hours. When
the device transitions to the constant voltage
mode, the timing counter is reset and will time out
after three hours and shut down the charger.
Mode
Trickle Charge (TC) Time Out
Trickle Charge (TC) +
Fast Charge (CC) Time Out
Constant Voltage (VC) Mode
Time Out
Time
25 minutes
3 hours
3 hours
Table 2: Summary for a 0.1μF Used for the
Timing Capacitor.
14
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 times would be doubled.
If the programmable watchdog timer function is not
needed, it may be disabled by connecting the CT
pin to ground. The CT pin should not be left floating or un-terminated, 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
closely as possible to the CT pin. Since the accuracy of the internal timer is dominated by the
capacitance value, 10% tolerance or better ceramic capacitors are recommended. Ceramic capacitor
materials such as X7R and X5R type 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 overvoltage protection threshold (VOVP). If an over-voltage condition occurs, the AAT3689 charge control
will shut down the device until voltage on the BAT
pin drops below the over-voltage protection threshold (VOVP). The AAT3689 will resume normal charging operation after the over-voltage condition is
removed. During an over-voltage event, the STAT
LEDs will report a system fault.
Over-Temperature Shutdown
The AAT3689 has a thermal protection control circuit which will shut down charging functions should
the internal die temperature exceed the preset
thermal limit threshold.
Battery Temperature Fault Monitoring
In the event of a battery over-temperature condition, the charge control will turn off the internal pass
device. The STAT LEDs will display a system fault.
After the system recovers from a temperature fault,
the device will resume charging operation.
3689.2006.11.1.0
AAT3689
0.5A/1.0A USB Port/Adapter
Lithium-Ion/Polymer Battery Charger
The AAT3689 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 to use negative temperature coefficient
(NTC) thermistors, which are typically integrated
into the battery package. Most commonly used
NTC thermistors used in battery packs are approximately 10kΩ at room temperature (25°C).
The TS pin has been specifically designed to
source 80μA of current to the thermistor. The voltage on the TS pin that results from the resistive
load should stay within a window from 330mV to
2.30V. If the battery becomes too hot during charging due to an internal fault, the thermistor will heat
up and reduce in value, thus pulling the TS pin voltage lower than the TS1 threshold and the AAT3689
will signal the fault condition.
If the use of the TS pin function is not required by
the system, it should be terminated to ground using
a 10kΩ resistor.
Battery Charge Status Indication
The AAT3689 has two status LED driver outputs.
These two LEDs can indicate simple functions
such as no battery charge activity, battery charging, charge complete, and charge fault.
Status Indicator Display
Simple system charging status may be displayed
using one or two LEDs in conjunction with the
STAT1 and STAT2 pins on the AAT3689. These two
pins are simple switches to connect the LED cathodes to ground. It is not necessary to use both display LEDs if a user simply wants to have a single
lamp to show "charging" or "not charging." This can
be accomplished by using the STAT1 pin and a single LED. Using two LEDs and both STAT pins simply gives the user more information to the charging
states. Refer to Table 3 for LED display definitions.
requirements. The LEDs should be biased with as
little current as necessary to create reasonable illumination; therefore, a ballast resistor should be
placed between the LED cathodes and the
STAT1/2 pins. LED current consumption will add to
the overall thermal power budget for the device
package, so it is wise to keep the LED drive current
to a minimum. 2mA should be sufficient to drive
most low-cost green or red LEDs. It is not recommended to exceed 8mA for driving an individual
status LED. The required ballast resistor value can
be estimated using the following formulas:
For connection to the adapter supply:
RB(STAT1/2) =
VADP - VF(LED)
ILED(STAT1/2)
Example:
RB(STAT1) =
5.5V - 2.0V
= 1.75kΩ
2mA
Note: Red LED forward voltage (VF) is typically
2.0V @ 2mA.
For connection to the USB supply:
RB(STAT1/2) =
VUSB - VF(LED)
ILED(STAT1/2)
Example:
RB(STAT2) =
5.0V - 3.2V
= 900Ω
2mA
Note: Green LED forward voltage (VF) is typically
3.2V @ 2mA.
The status LED display conditions are described in
Table 3.
The LED anodes should be connected to either
VUSB or VADP, depending upon the system design
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AAT3689
0.5A/1.0A USB Port/Adapter
Lithium-Ion/Polymer Battery Charger
Event Description
Charge Disabled or Low Supply
Charge Enabled Without Battery
Battery Charging
Charge Completed
Fault
STAT1
STAT2
Off
Flash1
On
Off
On
Off
Flash1
Off
On
On
Table 3: Status LED Display Conditions.
Capacitor Selection
Input Capacitor
In general, it is good design practice to place a
decoupling capacitor between the ADP and USB
pins and ground. 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 AAT3689 adapter input is to be used in a system with an external power supply source, such as
a typical AC-to-DC 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 bounce effects when the power
supply is "hot plugged." Likewise, a 10μF or greater
input capacitor is recommended for the USB input
to help buffer the effects of USB source power
switching, noise, and input cable impedance.
Output Capacitor
The AAT3689 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 AAT3689 is to be used in
applications where the battery can be removed
from the charger, such as in the case of 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 to the AAT3689
BAT pin as possible. To minimize voltage drops on
the PCB, keep the high current carrying traces adequately wide. For maximum power dissipation of
the AAT3689 TDFN package, the metal substrate
should be solder bonded to the board. It is also recommended to maximize the substrate contact to the
PCB ground plane layer to further increase local
heat dissipation.
1. Flashing rate depends on output capacitance.
16
3689.2006.11.1.0
AAT3689
0.5A/1.0A USB Port/Adapter
Lithium-Ion/Polymer Battery Charger
AAT3689 Evaluation Board Layout
Figure 5: AAT3689 Evaluation Board
Component Side Layout.
Figure 6: AAT3689 Evaluation Board
Solder Side Layout.
AAT3689 Evaluation Board Schematic Diagram
ON/OFF
J1
1 2 3
DS1 (b)
USB
GRN
LED D2
BAV74LT1
DS1 (a)
ADP
J2
0
U1
BAV74LT1
BAT
TS
C1
10μF
3689.2006.11.1.0
C2
10μF
C3
10μF
RED
LED D1
R3
10K
CT
C4
0.1μF
5
EN
1
USB
STAT2
7
3
ADP
STAT1
8
2
BAT
USBSET
11
6
TS
ADPSET
12
9
CT
GND
USB
10
4
R5
1.5K
R1
8.06K
R4
1.5K
R2
8.06K
AAT3689
17
AAT3689
0.5A/1.0A USB Port/Adapter
Lithium-Ion/Polymer Battery Charger
AAT3689 Evaluation Board Bill of Materials
18
Component
Part Number
Description
Manufacturer
U1
AAT3689IFP-4.2-T1
AnalogicTech
R1, R2
R3
R4, R5
C1, C2, C3
C4
JP1
JP2
D1
D2
DS1 (a, b)
Chip Resistor
Chip Resistor
Chip Resistor
GRM21BR61A106KE19
GRM188R71C104KA01
PRPN401PAEN
Chip Resistor
CMD15-21SRC/TR8
CMD15-21VGC/TR8
BAV74LT-A
0.5A/1.0A USB Port/Adapter
Lithium-Ion/Polymer Battery Charger;
12-Pin 3x3 TDFN Package
8.06KΩ, 1%, 1/4W; 0603
10KΩ, 5%, 1/4W; 0603
1.5KΩ, 5%, 1/4W; 0603
CER 10μF 10V 10% X5R 0805
CER 0.1μF 16V 10% X7R 0603
Conn. 3-pin Header, 2mm zip
0Ω
Red LED; 1206
Green LED; 1206
Default Diode; SOT23-3
Vishay
Vishay
Vishay
Murata
Murata
Sullins Electronics
Vishay
Chicago Miniature Lamp
Chicago Miniature Lamp
On Semi
3689.2006.11.1.0
AAT3689
0.5A/1.0A USB Port/Adapter
Lithium-Ion/Polymer Battery Charger
Ordering Information
Package
Marking1
Part Number (Tape and Reel)2
TDFN33-12
RQXYY
AAT3689IWP-4.2-T1
All AnalogicTech products are offered in Pb-free packaging. The term “Pb-free” means
semiconductor products that are in compliance with current RoHS standards, including
the requirement that lead not exceed 0.1% by weight in homogeneous materials. For more
information, please visit our website at http://www.analogictech.com/pbfree.
Package Information3
TDFN33-12
Index Area
0.43 ± 0.05
Detail "A"
0.45 ± 0.05
2.40 ± 0.05
3.00 ± 0.05
0.1 REF
3.00 ± 0.05
1.70 ± 0.05
Top View
Bottom View
0.23 ± 0.05
Pin 1 Indicator
(optional)
0.05 ± 0.05
0.23 ± 0.05
0.75 ± 0.05
Detail "A"
Side View
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.
3689.2006.11.1.0
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AAT3689
0.5A/1.0A USB Port/Adapter
Lithium-Ion/Polymer Battery Charger
© Advanced Analogic Technologies, Inc.
AnalogicTech cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in an AnalogicTech product. No circuit patent licenses, copyrights, mask work rights,
or other intellectual property rights are implied. AnalogicTech reserves the right to make changes to their products or specifications or to discontinue any product or service without notice.
Customers are advised to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. All products are sold subject to the terms and conditions of sale supplied at the time of order acknowledgement, including those pertaining to warranty, patent infringement, and limitation of liability. AnalogicTech
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AnalogicTech and the AnalogicTech logo are trademarks of Advanced Analogic Technologies Incorporated. All other brand and product names appearing in this document are registered trademarks or trademarks of their respective holders.
Advanced Analogic Technologies, Inc.
830 E. Arques Avenue, Sunnyvale, CA 94085
Phone (408) 737- 4600
Fax (408) 737- 4611
20
3689.2006.11.1.0