ANALOGICTECH AAT3670

PRODUCT DATASHEET
AAT3670
BatteryManagerTM
1.6A Dynamic Battery Charger and Power Manager
General Description
Features
The AAT3670 BatteryManager is a highly integrated single-cell lithium-ion/polymer (Li-ion) battery charger and
system power management IC that enables simultaneous battery charging and full system usage without compromising the battery’s charge cycle life. It operates with
low-voltage AC adapter (ADP) and USB inputs and
requires a minimum number of external components.
• ADP, USB, or Battery Powers System Load Through
Internal Current-Limited Switches
• Simultaneous Battery Charging and System Usage
• Voltage Sensed Charge Reduction Loop to Minimize
Charge Time, Even While the System Operates
• Digitized Thermal Loop
• Battery Power Enable (ENBAT)
• Battery Charge Timer (CT)
• Battery Temperature Monitoring (TS)
• Battery Charge Status Report (STATx)
• Automatic Recharge Sequencing
• Battery Under-Voltage, Over-Voltage, and OverCurrent Protection
• System Load Current Limiting
• Thermal Protection
• 24-pin 4x4mm QFN Package
The AAT3670 selects ADP or USB to power the system
load and charge the battery when ADP/USB power is
available. The AAT3670 precisely regulates battery
charge voltage and current for 4.2V Li-ion cells. Charge
current can be programmed up to 1.6A for ADP charging
and 0.9A or 0.1A for USB charging by resistors on the
ADPSET / USBSET pins. The charge termination current
threshold is set by an external resistor on the TERM pin.
The AAT3670 has a voltage-sensed charge current
reduction loop that enables system operation without a
power shortage. When the input voltage falls below the
programmable charge reduction threshold, the device
automatically reduces the charge current until the input
voltage returns to the threshold voltage.
Applications
•
•
•
•
•
•
Battery temperature and charge state are fully monitored
for fault conditions. In the event of a battery over-voltage/short-circuit/over-temperature condition, the charger will automatically shut down, protecting the charging
device, control system, and battery. Two status monitor
output pins (STAT1 and STAT2) are provided to indicate
battery charge status by directly driving external LEDs.
Cellular Telephones
Digital Still Cameras
Personal Data Assistants (PDAs)
Hand Held PCs
MP3 Players and PMP
Other Li-ion Battery Powered Devices
The AAT3670 is available in a Pb-free, thermallyenhanced, space-saving 24-pin 4x4mm QFN package.
Typical Application
STAT1
OUT
STAT2
BATS
BAT
ADP
Adapter Input
CADP
10µF
RT
ENBAT
Enable Battery to OUT
CHRADP
USBSEL
USB Hi/Lo Select
CHRUSB
ADPSET
USBSET
ADPLIM
USBLIM
3670.2008.04.1.5
Single Cell
Li-Ion/Poly
Battery
TS
EN
Enable
T
VTS
CUSB
10µF
RUSBSET
CBAT
10µF
AAT3670
USB
USB Input
RADPSET
System Load
RADPLIM
RUSBLIM
CT
TERM
CT
GND
RTERM
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1
PRODUCT DATASHEET
AAT3670
BatteryManagerTM
1.6A Dynamic Battery Charger and Power Manager
Pin Descriptions
Pin #
2
Name
Type
1
USBSEL
I
2, 3
OUT
O
4, 5
BAT
I/O
6
7
ADP
VTS
I
O
8
TS
I
9
BATS
I
10
CHRADP
I/O
11
ADPLIM
I
12
USBLIM
I
13
ADPSET
I
14
USBSET
I
15
GND
I/O
16
TERM
I
17
EN
I
18
CT
I
19
20
21
STAT2
STAT1
N/C
O
O
22
USB
I
23
CHRUSB
I/O
24
EP
ENBAT
I
Function
Logic input. High for 100% USB charge current set by USBSET; low for 20% (constant current charge mode) or 50% (trickle charge mode) charge current set by the USBSET resistor.
System load output; a capacitor with a minimum value of 10µF (including all capacitance on
the load of OUT) is required.
Battery pack input/output. For best operation, a 1µF ceramic capacitor should be placed
between BAT and GND.
AC adapter input, source of system load and battery charging. Minimum 1µF input capacitor.
Voltage reference for battery temperature sensing.
Battery temperature sensing input. Use an NTC resistor from TS pin to ground and a 1%
standard resistor that has equal resistance of the NTC at 25°C from VTS to TS for battery
temperature sensing. Tie TS pin to ground to disable the temperature sensing function.
Battery sense pin.
ADP voltage sensed charge reduction programmable pin. A resistor divider from ADP to this
pin and GND sets the charge reduction threshold. When this pin is open, the charge reduction threshold is 4.6V. If this pin is tied to the ADP pin, the charge reduction is disabled.
Connect a resistor to this pin to set the ADP input current limit (including load switch and
charger currents).
Connect a resistor to this pin to set the USB input current limit (including load switch and
charger currents).
Connect a resistor to this pin to set the ADP charge current (for trickle charge and constant
current charge). The CC current set by this pin should be less than the current limit set by
ADPLIM, otherwise the CC current will be limited by ADPLIM.
Connect a resistor to this pin to set the USB charge current (for trickle charge and constant
current charge). The CC current set by this pin should be less than the current limit set by
USBLIM, otherwise the CC current will be limited by USBLIM.
Common ground.
Connect a resistor to this pin to program the charge termination current threshold. No termination current setting when this pin is pulled up to a logic high level.
ADP/USB enable input. High or floating (internal pull-up) to enable ADP/USB switch and ADP/
USB battery charging; low to disable ADP/USB switch and ADP/USB battery charging.
Battery charge timer input pin. Connect a capacitor to this pin to set the ADP charge timers.
No time-out for USB charging. Timers are disabled when this pin is grounded. The timer is
suspended if the battery temperature is not within 0 to 50ºC or is in charge reduction (either
due to the supply voltage dropping or the device temperature rising) is activated. The timer
continues where it left off after the battery temperature returns to normal and the device is
out of the charge reduction loops.
Open drain charger status reporting.
Open drain charger status reporting.
No connection.
USB input, source of system load and battery charging when ADP is not available. Minimum
1µF input capacitor.
USB voltage sensed charge reduction programmable pin. A resistor divider from USB to this
pin and GND sets the charge reduction threshold. When this pin is open, the charge reduction threshold is 4.5V. If this pin is tied to the USB pin, charge reduction is disabled.
Battery load switch enable, active high.
Exposed paddle (bottom). Connect to ground as closely as possible to the device.
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3670.2008.04.1.5
PRODUCT DATASHEET
AAT3670
BatteryManagerTM
1.6A Dynamic Battery Charger and Power Manager
Pin Configuration
QFN44-24
(Top View)
STAT2
STAT1
N/C
USB
CHRUSB
ENBAT
19
20
21
22
23
24
USBSEL
OUT
OUT
BAT
BAT
ADP
1
18
2
17
3
16
4
15
5
14
6
13
CT
EN
TERM
GND
USBSET
ADPSET
12
11
9
10
8
7
USBLIM
ADPLIM
CHRADP
BATS
TS
VTS
Absolute Maximum Ratings1
Symbol
VP
VP
VN
TJ
TLEAD
Description
ADP, USB, BAT, OUT, BATS <30ms, Duty Cycle < 10%
ADP, USB BAT, OUT, BATS Continuous
USBSEL, EN, ENBAT, STAT1, STAT2
VTS, TS, CT, ADPLIM, USBLIM, ADPSET, USBSET, TERM, CHRADP, CHRUSB
Operating Junction Temperature Range
Maximum Soldering Temperature (at Leads)
Value
Units
-0.3 to 7.0
-0.3 to 6
-0.3 to 6
-0.3 to VP + 0.3
-40 to 150
300
V
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 a FR4 board.
3670.2008.04.1.5
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3
PRODUCT DATASHEET
AAT3670
BatteryManagerTM
1.6A Dynamic Battery Charger and Power Manager
Electrical Characteristics
VADP = 5V, TA = -40°C to +85°C; unless otherwise noted, typical values are TA = 25°C.
Symbol
Description
Conditions
Min
Typ
Max
Units
4.35
5.5
V
4.35
3.0
5.5
VBAT_EOC
V
V
Operation
VADP
VUSB
VBAT
AC Adapter Operating Voltage
Range
USB Operating Voltage Range
Battery Operating Voltage Range
VUVLO_ADP
ADP Under-Voltage Lockout
VUVLO_USB
USB Under-Voltage Lockout
VUVLO_BAT
BAT Under-Voltage Lockout
IADP_OP
IADP_SHDN
IUSB_OP
IUSB_SHDN
ADP
ADP
USB
USB
Normal Operating Current
Shutdown Mode Current
Normal Operating Current
Shutdown Mode Current
IBAT_OP
Battery Operating Current
IBAT_SLP
Battery Sleep Current
IBAT_SHDN
Leakage Current from BAT Pin
Power Switches
RDS(ON)_SWA ADP-to-OUT FET On Resistance
RDS(ON)_SWU USB-to-OUT FET On Resistance
RDS(ON)_SWB
BAT-to-OUT FET On Resistance
ADP Battery Charging FET
On Resistance
USB Battery Charging FET
RDS(ON)_CHU
On Resistance
Battery Charge Voltage Regulation
Output Charge Voltage Regulation1
VBAT_EOC
VMIN
Preconditioning Voltage Threshold
RDS(ON)_CHA
VRCH
VCHR_TH
VCHR_REG
Rising Edge
Hysteresis
Rising Edge
Hysteresis
Rising Edge
Hysteresis
VADP = VEN = 5V, ICC = 1A
VADP = 5V, VEN = 0V, VENBAT = 0V, No Load
VUSB = VEN = 5V, ICC = 0.5A
VUSB = 5V, VEN = 0V, VENBAT = 0V, No Load
VBAT = VBAT_EOC, VADP = GND, VUSB = GND,
VENBAT = 5V, No Load
VBAT = VBAT_EOC, VADP = 5V or VUSB = 5V,
VEN = VENBAT = 5V
VBAT = VBAT_EOC, VENBAT = 0V
V
V
3.0
V
1
1
1
1
mA
µA
mA
µA
45
80
µA
2
5
µA
1
µA
0.2
165
Ω
Ω
Ω
mΩ
0.5
VADP = 5.0V
VUSB = 5.0V
VBAT = 4.2V
VBAT = 4.2V, TA = 25°C
0.4
0.7
0.1
VADP = 5.0V
0.4
Ω
VUSB = 5.0V
0.7
Ω
For 4.2V Cells
Battery Recharge Voltage Threshold
Default ADP Charge Reduction
Threshold
Default USB Charge Reduction
Threshold
CHRADP and CHRUSB Pin Voltage
Accuracy
2.8
3.6
0.3
3.6
0.3
2.9
0.1
0.5
4.158
2.8
VBAT_EOC
-0.17
CHRADP Open; Reduce Charge Current
When ADP is Below VCHR_TH
CHRUSB Open; Reduce Charge Current
When USB is Below VCHR_TH
4.20
2.9
VBAT_EOC
-0.1
4.242
3.0
VBAT_EOC
-0.05
V
V
V
4.6
V
4.5
1.9
2.0
2.1
V
1. The output charge voltage accuracy is specified over the 0° to 70°C ambient temperature range; operation over the -40°C to +85°C temperature range is guaranteed by
design.
4
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3670.2008.04.1.5
PRODUCT DATASHEET
AAT3670
BatteryManagerTM
1.6A Dynamic Battery Charger and Power Manager
Electrical Characteristics (continued)
VADP = 5V, TA = -40°C to +85°C; unless otherwise noted, typical values are TA = 25°C.
Symbol
Description
Conditions
Current Regulation
Maximum ADP Current Limit
ILIM_ADP
ILIM_USB
Maximum USB Current Limit
BAT_OUT Current Limit (Fixed)
ILIM_BAT
ICH_CC_ADP
ADP Charge Constant Current Charge Range
USB High-Power Charge Constant Current
ICH_CC_USB_H
Charge Range
USB Low-Power Charge Constant Current
ICH_CC_USB_L
Charge Range
∆ICH_CC/
Current Regulation Tolerance
ICH_CC
ICH_TKL_ADP
ADP Charge Trickle Charge
ICH_TKL_USB_H USB High-Power Charge Trickle Charge
ICH_TKL_USB_L USB Low-Power Charge Trickle Charge
VADPLIM
ADPLIM Pin Voltage Regulation
VUSBLIM
USBLIM Pin Voltage Regulation
ADPSET Pin Voltage Regulation
VADPSET
VUSBSET
USBSET Pin Voltage Regulation
TERM Pin Voltage Regulation
VTERM
Constant Current Charge Current Set Factor:
KI_CC_ADP
ICH_ADP/IADPSET
Constant Current Charge Current Set Factor:
KI_CC_USBH
ICH_USB/IUSBSET
Constant Current Charge Current Set Factor:
KI_CC_USBL
ICH_USB/IUSBSET
KI_LIM_ADP
Current Limit Set Factor: ILIM_ADP/IADPLIM
Current Limit Set Factor: ILIM_USB/IUSBLIM
KI_LIM_USBH
KI_LIM_USBL
Current Limit Set Factor: ILIM_USB/IUSBLIM
Termination Current Set Factor: ICH_TERM/ITERM
KI_TERM
3670.2008.04.1.5
Max
Units
1.6
0.9
2.3
100
1600
A
A
A
mA
USBSEL = 5V
50
900
mA
USBSEL = 0V
10
180
mA
ICH_CC_ADP = 1A; ICH_CC_USB_H
= 0.5A; ICH_CC_USB_L = 0.1A
-12
12
%
USBSEL = 5V
USBSEL = 0V
Min
Typ
10
10
50
2
2
2
2
2
% ICH_CC_ADP
% ICH_CC_USBH
% ICH_CC_USBL
V
V
V
V
V
29300
USBSEL = 5V
17900
USBSEL = 0V
3600
USBSEL = 5V
USBSEL = 0V
27800
17600
3500
2000
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PRODUCT DATASHEET
AAT3670
BatteryManagerTM
1.6A Dynamic Battery Charger and Power Manager
Electrical Characteristics (continued)
VADP = 5V, TA = -40°C to +85°C; unless otherwise noted, typical values are TA = 25°C.
Symbol
Description
Conditions
Logic Control/Protection
VEN
Input High Threshold
VEN
Input Low Threshold
VSTATx
Output Low Voltage
Fast Charge (Constant Current and Constant
TC
Voltage Charges Together) Timeout
TTKL
Trickle Charge Timeout
VOVP
Battery Over-Voltage Protection Threshold
IOCP
IVTS
Battery Charge Over-Current Protection Threshold
VTS Sourcing Capability
TS1
TS Hot Temperature Fault
TS2
TS Cold Temperature Fault
TLOOP_IN
TLOOP_OUT
TLOOP_REG
TSHDN
6
Digital Thermal Loop Entry Threshold
Digital Thermal Loop Exit Threshold
Digital Thermal Loop Regulated Temperature
Chip Thermal Shutdown Temperature
Min
Typ
Max
Units
0.4
0.4
V
V
V
1.6
STATx Pin Sinks 8mA
ADP
CCT = 100nF
USB
ADP
USB
VBAT_EOC +
0.1
In All Modes
VVTS = 2.5V
Threshold
Hysteresis
Threshold
Hysteresis
For ADP Charging
For ADP Charging
For ADP Charging
Threshold
Hysteresis
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1
28
70
6
infinite
Tc/8
infinite
VBAT_EOC
+ 0.15
100
30
2
72
2
115
95
100
140
15
hour
VBAT_EOC
+ 0.2
V
%ICH_CC
mA
32
74
%VTS
%VTS
ºC
ºC
ºC
ºC
3670.2008.04.1.5
PRODUCT DATASHEET
AAT3670
BatteryManagerTM
1.6A Dynamic Battery Charger and Power Manager
Typical Characteristics
Constant Current vs. Set Resistor
Adapter Mode Supply Current vs. ADPSET Resistor
(VIN = 5V; VBAT = 3.5V)
(VIN = 5V; VBAT = 3.5V)
0.8
ADP
1.6
Supply Current (mA)
Constant Current (A)
1.8
1.4
1.2
1.0
USBH
0.8
0.6
0.4
USBL
0.2
0.7
I CCM
0.6
0.5
0.4
I TRICKLE
0.3
0.2
0.1
0.0
10
100
1000
10
100
Set Resistor (kΩ
Ω)
1000
ADPSET Resistor (kΩ
Ω)
USB Mode Supply Current vs. USBSET Resistor
USB Mode Supply Current vs. USBSET Resistor
(USBL; VIN = 5V; VBAT = 3.5V)
(USBH; VIN = 5V; VBAT = 3.5V)
0.8
Supply Current (mA)
Supply Current (mA)
0.8
0.7
I CCM
0.6
0.5
0.4
I TRICKLE
0.3
0.2
0.1
0.7
I CCM
0.6
I TRICKLE
0.5
0.4
0.3
0.2
0.1
10
100
1000
10
100
USBSET Resistor (kΩ
Ω)
USBSET Resistor (kΩ
Ω)
4.24
4.22
USBH
4.20
ADP
4.18
4.16
4.5
4.75
5.0
5.25
End of Charge Voltage vs. Temperature
End of Charge Voltage (V)
End of Charge Voltage (V)
End of Charge Voltage vs. Supply Voltage
USBL
5.5
4.24
4.22
USBH
ADP
4.20
4.18
4.16
-40
USBL
-15
10
35
60
85
Temperature (°°C)
Supply Voltage (V)
3670.2008.04.1.5
1000
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PRODUCT DATASHEET
AAT3670
BatteryManagerTM
1.6A Dynamic Battery Charger and Power Manager
Typical Characteristics
Recharge Threshold Voltage vs. Temperature
Preconditioning Threshold Voltage vs. Temperature
(VIN = 5.0V)
4.20
Preconditioning Threshold
Voltage (V)
Recharge Threshold Voltage (V)
(VIN = 5.0V)
4.16
ADP
4.12
USBH
4.08
USBL
4.04
4.00
3.96
-40
-15
10
35
60
85
3.05
3.00
ADP
USBH
2.95
2.90
2.85
USBL
2.80
2.75
-40
-15
Temperature (°°C)
Preconditioning Charging
Current (mA)
BAT to OUT Switch Voltage (V)
+85°C
400
600
120
ADP
100
80
60
40
USBH, USBL
20
0
-40
800 1000 1200 1400 1600 1800 2000 2200
-15
Charging Current vs. Battery Voltage
60
85
(USBH; USBSET = 71.5KΩ
Ω)
1200
600
Charging Current (mA)
Charging Current (mA)
35
Charging Current vs. Battery Voltage
(ADP; ADPSET = 57.6KΩ
Ω)
1000
800
600
400
200
500
400
300
200
100
0
2.9
3.3
3.7
4.1
4.5
Battery Voltage (V)
8
10
Temperature (°°C)
Load Current (mA)
2.5
85
(VIN = 5.0V)
-40°C
25°C
200
60
Preconditioning Charging Current vs. Temperature
(VBAT = 3.95V)
0
35
Temperature (°°C)
BAT to OUT Switch Voltage vs. Load Current
1.2
1
0.8
0.6
0.4
0.2
0
-0.2
-0.4
-0.6
-0.8
-1
-1.2
10
0
2.5
2.9
3.3
3.7
4.1
4.5
Battery Voltage (V)
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3670.2008.04.1.5
PRODUCT DATASHEET
AAT3670
BatteryManagerTM
1.6A Dynamic Battery Charger and Power Manager
Typical Characteristics
Charging Current vs. Battery Voltage
Constant Charge Current vs. Temperature
(USBL; USBSET = 71.5KΩ
Ω)
Charging Current (mA)
120
100
80
60
40
20
0
2.5
2.9
3.3
3.7
4.1
4.5
Constant Charge Current (mA)
(VIN = 5.0V)
1100
1000
ADP
900
800
700
600
500
USBH
400
300
200
100
USBL
0
-40
-15
10
35
60
85
Temperature (°°C)
Constant Charging Current vs. Supply Voltage
Constant Charging Current vs. Supply Voltage
Constant Charging Current (mA)
Constant Charging Current (mA)
Battery Voltage (V)
(ADP; CHRADP = Open; ADPSET = 57.6kΩ
Ω)
1200
1000
800
VBAT = 3.3V, 3.6V, 3.9V
600
400
200
0
4.0
4.5
5.0
5.5
6.0
(ADP; CHRADP = USB; ADPSET = 57.6kΩ
Ω)
1200
VBAT = 3.3V
1000
800
VBAT = 3.6V
600
VBAT = 3.9V
400
200
0
4.0
4.5
5.5
6.0
Constant Charging Current vs. Supply Voltage
Constant Charging Current vs. Supply Voltage
Constant Charging Current (mA)
Supply Voltage (V)
Constant Charging Current (mA)
Supply Voltage (V)
5.0
(USBL; CHRUSB = Open; USBSET = 71.5kΩ
Ω)
120
VBAT = 3.3V, 3.6V
100
80
VBAT = 3.9V
60
40
20
0
4.0
4.5
5.0
5.5
6.0
(USBL; CHRUSB = USB; USBSET = 71.5kΩ
Ω)
120
VBAT = 3.3V
100
80
40
VBAT = 3.9V
20
0
4.0
Supply Voltage (V)
3670.2008.04.1.5
VBAT = 3.6V
60
4.5
5.0
5.5
6.0
Supply Voltage (V)
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PRODUCT DATASHEET
AAT3670
BatteryManagerTM
1.6A Dynamic Battery Charger and Power Manager
Constant Charging Current vs. Supply Voltage
Constant Charging Current vs. Supply Voltage
Constant Charging Current (mA)
Constant Charging Current (mA)
Typical Characteristics
(USBH; CHRUSB = Open; USBSET = 71.5kΩ
Ω)
600
VBAT = 3.3V
500
VBAT = 3.9V
400
VBAT = 3.6V
300
200
100
0
4.0
4.5
5.0
5.5
6.0
(USBH; CHRUSB = USB; USBSET = 71.5kΩ
Ω)
600
VBAT = 3.3V
500
400
VBAT = 3.6V
300
200
VBAT = 3.9V
100
0
4.0
4.5
Constant Charging Current vs.
Supply Voltage
(ADP; CHRADP = Open; VBAT = 3.6V; ADPSET = 57.6KΩ
Ω)
1200
1000
25°C
800
+85°C
600
400
-40°C
200
0
4.3
4.4
4.5
4.6
4.7
6.0
4.8
4.9
Constant Charging Current vs.
Supply Voltage
(USBL; CHRUSB = Open; VBAT = 3.6V; USBSET = 71.5KΩ
Ω)
120
-40°C
100
+85°C
+25°C
80
60
40
20
0
Supply Voltage (V)
Constant Charging Current (mA)
5.5
Supply Voltage (V)
Constant Charging Current (mA)
Constant Charging Current (mA)
Supply Voltage (V)
5.0
4.3
4.4
4.5
4.6
4.7
4.8
4.9
Supply Voltage (V)
Constant Charging Current vs.
Supply Voltage
(USBH; CHRUSB = Open; VBAT = 3.6V; USBSET = 71.5KΩ
Ω)
600
-40°C
500
25°C
400
+85°C
300
200
100
0
4.3
4.4
4.5
4.6
4.7
4.8
4.9
Supply Voltage (V)
10
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3670.2008.04.1.5
PRODUCT DATASHEET
AAT3670
BatteryManagerTM
1.6A Dynamic Battery Charger and Power Manager
Typical Characteristics
VIH vs. Supply Voltage
VIL vs. Supply Voltage
(ADP or USBL or USBH; EN = Rising)
(ADP or USBL or USBH; EN = Falling)
1.2
1.2
1.1
1.1
-40°C
25°C
0.9
0.8
0.7
85°C
0.6
-40°C
1.0
VIL (V)
VIH (V)
1.0
0.9
0.8
0.7
0.6
+85°C
0.5
0.5
0.4
4.2
4.4
4.6
4.8
5.0
5.2
5.4
5.6
5.8
0.4
4.2
6.0
4.4
4.6
4.8
Supply Voltage (V)
5.0
5.2
5.4
5.6
5.8
6.0
5.8
6.0
Supply Voltage (V)
VIH vs. Supply Voltage
VIL vs. Supply Voltage
(ENBAT = Rising)
(ENBAT = Falling)
1.2
1.2
1.1
1.1
-40°C
1.0
25°C
0.9
0.8
0.7
85°C
0.6
25°C
-40°C
1.0
VIL (V)
VIH (V)
25°C
0.9
0.8
0.7
85°C
0.6
0.5
0.5
0.4
4.2
4.4
4.6
4.8
5.0
5.2
5.4
5.6
5.8
0.4
4.2
6.0
4.4
4.6
4.8
Battery Voltage (V)
5.0
5.2
5.4
5.6
Battery Voltage (V)
Adapter and Charging Current vs. Output Current
USB and Charging Current vs. Output Current
(VBAT = 3.6V)
(USBL; VBAT = 3.6V)
1800
400
IADP
200
1400
Current (mA)
Current (mA)
1600
1200
1000
ICH
800
600
0
-600
-800
200
-1000
200
400
600
800
1000
Output Current (mA)
3670.2008.04.1.5
ICH
-400
400
0
IUSBL
-200
0
200
400
600
800
1000
Output Current (mA)
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11
PRODUCT DATASHEET
AAT3670
BatteryManagerTM
1.6A Dynamic Battery Charger and Power Manager
Typical Characteristics
USB and Charging Current vs. Output Current
ADP Charge Current vs. Time
(USBH; VBAT = 3.6V)
Current (mA)
IUSBH
600
400
ICH
200
0
-200
0
200
400
600
800
4.5
4.0
Charge Reduction
Mode Activated
0.5
0.0
1.0
0.5
0.0
0
1000
1
2
Output Current (mA)
3
4
5
Time
USB Charge Current vs. Time
CT Current vs. Temperature
(USBH)
(CT = 0.1F)
5.0
550
Charge Reduction
Mode Activated
4.0
0.5
0.0
0.5
0.0
0
1
2
3
548
CT Current (nA)
4.5
USB Charge Current (A)
USB Voltage (top) (V)
USB Peripheral Current
Consumption (middle) (A)
1.0
ADP Charge Current (A)
1000
800
5.0
ADP Voltage (top) (V)
ADP Peripheral Current
Consumption (middle) (A)
1200
546
Constant
Current
544
542
Preconditioning
540
538
536
534
532
-40
4
-15
10
35
60
85
Temperature (°°C)
Time
CT Timeout vs. Temperature
CT Pin Capacitance vs. Counter Timeout
(CT = 0.1F)
1.0
Constant Current
6
5
4
3
2
Preconditioning
1
0.8
0.7
0.6
0.5
0.4
Constant Current Timeout
0.3
0.2
0.1
0
0.0
-40
-15
10
35
60
85
Temperature (°°C)
12
Preconditioning Timeout
0.9
Capacitance (µF)
CT Timeout (Hour)
7
0
10
20
30
40
50
60
Time (hours)
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3670.2008.04.1.5
PRODUCT DATASHEET
AAT3670
BatteryManagerTM
1.6A Dynamic Battery Charger and Power Manager
Typical Characteristics
Percentage of VVTS vs. Temperature
Total Input Current vs. Output Current
(ADP or USBH or USBL; VIN = 5V)
(VBAT = 3.6V)
1800
70
I ADP
1600
VTS2
Input Current (mA)
Percentage of VVTS (%)
80
60
50
40
VTS1
30
20
10
1400
1200
I USBH
1000
800
600
IUSBL
400
200
0
0
-40
-15
10
35
60
0
85
200
Transient Response of OUT
When Switching from BAT to ADP
(VADP = 5V ➜ 0V)
(VADP = 0V ➜ 5V)
OUT
4
3
BAT
ADP
1
0
4
OUT
3
2
BAT
ADP
1
0
Time (500µs/div)
Transient Response of OUT
When Switching From USBH to BAT
Transient Response of OUT
When Switching From BAT to USBH
(VUSBH = 5V ➜ 0V; RLOAD = 7.8Ω)
(VUSBH = 0V ➜ 5V; RLOAD = 7.8Ω)
5
4
3
BAT
OUT
1
0
Voltage (V)
USBH
Voltage (V)
1000
5
Time (500µs/div)
2
800
Transient Response of OUT
When Switching from ADP to BAT
5
2
600
Output Current (mA)
Voltage (V)
Voltage (V)
Temperature (°°C)
400
5
USBH
4
3
2
OUT
1
0
Time (500µs/div)
3670.2008.04.1.5
BAT
Time (500µs/div)
www.analogictech.com
13
PRODUCT DATASHEET
AAT3670
BatteryManagerTM
1.6A Dynamic Battery Charger and Power Manager
Typical Characteristics
Transient Response of OUT
When Switching From USBL to BAT
Transient Response of OUT
When Switching From BAT to USBL
(VUSBL = 5V ➜ 0V; RLOAD = 50Ω)
(VUSBL = 0V ➜ 5V; RLOAD = 50Ω)
USBL
Voltage (V)
Voltage (V)
USBL
5
4
3
2
BAT
OUT
1
5
4
3
2
BAT
OUT
1
0
0
Time (500µs/div)
Time (500µs/div)
Transient Response of OUT
When Switching From USBL to ADP
Transient Response of OUT
When Switching From ADP to USBL
(VADP = 5V ➜ 0V; RLOAD = 50Ω)
(VADP = 0V ➜ 5V; RLOAD = 50Ω)
4
OUT
3
2
1
ADP
USBL
Voltage (V)
Voltage (V)
USBL
5
5
4
3
2
Time (500µs/div)
Time (500µs/div)
Transient Response of OUT
When Switching From ADP to USBH
Transient Response of OUT
When Switching From USBH to ADP
(VADP = 0V ➜ 5V; RLOAD = 7.8Ω)
(VADP = 5V ➜ 0V; RLOAD = 7.8Ω)
USBH
5
4
OUT
3
ADP
1
0
Voltage (V)
Voltage (V)
USBH
5
4
OUT
3
2
1
ADP
0
Time (100µs/div)
14
ADP
1
0
0
2
OUT
Time (100µs/div)
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3670.2008.04.1.5
PRODUCT DATASHEET
AAT3670
BatteryManagerTM
1.6A Dynamic Battery Charger and Power Manager
Typical Characteristics
Transient Response of OUT When ADP is On
When USBH Switching from On to Off
Transient Response of OUT When ADP is On
When USBH Switching from Off to On
(VUSBH = 5V ➜ 0V; RLOAD = 7.8Ω)
(VUSBH = 0V ➜ 5V; RLOAD = 7.8Ω)
ADP
4
3
OUT
USBH
2
1
Voltage (V)
Voltage (V)
ADP
5
0
5
4
3
2
USBH
1
0
Time (500µs/div)
Time (500µs/div)
Transient Response of OUT
When Switching From ADP to USBL
Transient Response of OUT
When Switching From USBL to ADP
(VUSBL = 5V ➜ 0V; RLOAD = 50Ω)
(VUSBL = 0V ➜ 5V; RLOAD = 50Ω)
ADP, OUT
5
4
3
2
1
USBL
0
Voltage (V)
ADP, OUT
Voltage (V)
OUT
5
4
3
2
0
Time (500µs/div)
3670.2008.04.1.5
USBL
1
Time (500µs/div)
www.analogictech.com
15
PRODUCT DATASHEET
AAT3670
BatteryManagerTM
1.6A Dynamic Battery Charger and Power Manager
Functional Block Diagram
Switch 1
OUT
ADP
EN
Switch 3
ADP Charge
USB Charge
Switch 2
USB
BAT
ENBAT
CT
BATS
TERM
Temperature and
Current Sense
ADPSET
USBSET
Voltage
Sense
Charge
System
Control
Ref.
ADPLIM
USBLIM
USBSEL
TS
Temp.
Sense
VTS
CHRADP
Ref.
CHRUSB
STAT1
GND
STAT2
Functional Description
The AAT3670 is a dual input dynamic battery charge and
power control IC. The dual input capability is designed to
accommodate both AC power adapter and USB port
power sources. In addition, this device also provides
dynamic power control to charge a single cell Li-ion battery cell and power a system simultaneously.
The device contains separate charge regulation pass
devices to control the charge current or voltage for both
the adapter (ADP) and USB (USB) input power paths.
The AAT3670 also contains three additional load switches
to control and route input power to charge the battery,
supply the system load and manage power from the battery 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.
16
When an input power source is applied to the AAT3670,
the device selects the adapter or USB input to provide
power to the system load and charge the battery. If power
is present on both the ADP and USB inputs, the system
will select the ADP input since it provides greater power
levels and charges the battery with a greater current.
Without a valid ADP/USB supply present, the battery will
power the system load as long as the battery voltage is
greater than 2.9V. The 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 overdischarge which would result in shortened battery life.
The system load current drawn from the battery is limited
internally. The AAT3670 precisely regulates battery charge
voltage and current for 4.2V Li-ion battery cells, and the
battery charge current can be programmed up to 1.6A for
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3670.2008.04.1.5
PRODUCT DATASHEET
AAT3670
BatteryManagerTM
1.6A Dynamic Battery Charger and Power Manager
ADP charging and up to 0.9A for USB charging. During
battery charge, the AAT3670 pre-conditions (trickle
charge) the battery with lower current when the battery
voltage is less than 2.9V, and it charges the battery in a
constant current mode when the battery voltage is above
2.9V. When the battery voltage rises to 4.2V, the charger
will automatically switch to a constant voltage mode until
the charge current is reduced to the programmed charge
termination current threshold. The internal arrangement
of load switches and charge regulation device also provide dynamic power sourcing to the system load. If the
system load exceeds the input current supply from the
adapter or USB source, additional current can be sourced
from the battery cell. At all times, the device will manage
distribution of power between the source, the battery and
the system simultaneously in order to support system
power needs and charge the battery cell with the maximum amount of current possible.
The AAT3670 has a unique internal charge current
reduction loop control that will prevent an input source
from overload. In the case of USB charging from a USB
port VBUS supply, there are two events which need to be
guarded against. The first is charging from a defective or
inadequate USB host supply; the second problem could
arise if the programmed USB charge current plus the
system supply demand through the AAT3670 exceeds
the ability of a given USB port. In either case, the
AAT3670 charge reduction (CHR) loop will activate when
the input source to the USB input drops below the VCHR_TH
threshold of 4.5V. The CHR loop will automatically reduce
the charge current to the battery until the supply voltage
recovers to a point above the VCHR_TH threshold. The CHR
loop protection system also operates in the adapter input
mode with a 4.6V VCHR_TH threshold. This protects the
charger, system and source supply in the event an
adapter or power source does not meet the ADP charging mode specification. In USB or adapter mode charging, the CHR system will permit the charging of a battery
cell with the maximum possible amount of charge current for any given source fault condition.
During battery charging, the device temperature will
rise. In some cases with adapter (ADP) charging, the
power dissipation in the device may cause the 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 tem-
3670.2008.04.1.5
perature or excessive power dissipation condition, the
AAT3670 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. 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 temperature and charge state are fully monitored for fault conditions. In the event of an over-voltage, over-current, 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 AAT3670 also provides a temperature
sense feedback function (VTS/TS pins) 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 by two simple status LEDs.
Charging Operation
The AAT3670 has four basic modes for the battery
charge cycle regardless of which charge input function is
selected, either the adapter input or USB input: preconditioning/trickle charge, constant current fast charge,
constant voltage, and end of charge/sleep mode.
Battery Preconditioning
Before the start of charging, the AAT3670 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
AAT3670 checks the state of the battery via the battery
voltage sensing (BATS) pin. If the cell voltage is below
the preconditioning voltage threshold (VMIN), the AAT3670
begins preconditioning the cell.
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17
PRODUCT DATASHEET
AAT3670
BatteryManagerTM
1.6A Dynamic Battery Charger and Power Manager
Preconditioning
Trickle Charge
Phase
Constant Current
Charge Phase
Constant Voltage
Charge Phase
End of Charge Voltage
Regulated Current
Constant Current Mode
Voltage Threshold
(4.2V)
I = Max CC
(2.9V)
Trickle Charge
Charge Termination Current
Figure 1: Current vs. Voltage Profile During Charging Phases.
The battery preconditioning trickle charge current is
equal to the fast charge constant current divided by 10
for the adapter and USB high input modes. For example,
if the programmed fast charge current is 500mA, then
the preconditioning mode (trickle charge) current will be
50mA. In the USB low charging mode, the preconditioning current is set to the programmed fast charge current
divided by two. Cell preconditioning is a safety precaution for a deeply discharged battery and also aids in
limiting power dissipation in the charge control pass
transistor when the voltage across the device is at the
greatest potential.
Fast Charge/Constant Current Charging
Battery cell preconditioning continues until the voltage
measured by the battery sense (BATS) pin exceeds the
preconditioning voltage threshold (VMIN). At this point,
the AAT3670 begins constant-current charging fast
charging phase. The fast charge constant current (ICC)
level is determined by the charge mode (ADP, USBH or
USBL) and is programmed by the user via the RADPSET and
RUSBSET resistors. The AAT3670 remains in constant current charge mode until the battery reaches the voltage
regulation point, VBAT_EOC.
18
Constant Voltage Charging
The charge control system transitions to a regulated constant voltage charging mode when the battery voltage
reaches output charge regulation threshold (VBAT_EOC) during 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 the user programmed
charge termination current at the end of the constant voltage charging phase, the device terminates charging and
enters the sleep state. The charger will remain in the sleep
state until the battery voltage decreases to a level below
the battery recharge voltage threshold (VRCH). The charge
termination current is programmed via the RTERM resistor.
When the input supply is disconnected, the charger also
automatically enters power-saving sleep mode. Only
consuming an ultra-low 1µA in sleep mode, the AAT3670
minimizes battery drain when not charging. This feature
is particularly useful in applications where the input supply level may fall below the usable range of the charge
reduction control or under-voltage lockout level. In such
cases where the AAT3670 input voltage drops, the device
will enter the sleep mode and automatically resume
charging once the input supply has recovered from its
fault condition.
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3670.2008.04.1.5
PRODUCT DATASHEET
AAT3670
BatteryManagerTM
1.6A Dynamic Battery Charger and Power Manager
Yes
Power On
Reset
UVLO
VP > VUVLO
Yes
Switch
On
No
No
Thermal
Loop Enable
Sleep
Mode
No
Fault
Condition
Monitor
OV, OT,
OC
Enable
Dynamic Charge
VEN_BAT > VEN
Yes
Yes
No
Shutdown
Mode
Device
Temp. Monitor
TJ > 110degC
Yes
No
Connect
ADP to BAT
and OUT
Yes
Battery Temp.
Sense
VTS1 < TS < VTS2
No
Thermal Loop
Current Reduction
Battery
Temperature
Fault
Expire
Charge Timer
(Enable on
Charger reset)
Power
Share
Recharge Test
VRCH > VBAT ?
Yes
Preconditioning
Test
VMIN > VBAT
Yes
Low Current
Conditioning
Charge
Set
No
No
Current Limit
Test
IOUT > ILIM
Yes
Reduce Charging
Current to BAT
Current Phase
Test
VEOC > VBAT
Yes
Constant Current
Charging Mode
No
Voltage Phase
Test
IBAT > ITERM
Yes
Constant Voltage
Charge Mode
Charge Reduction
Mode
No
IOUT + IBAT > ILIM ?
No
Yes
Yes
Charge
Complete
Voltage
Regulation
Enable
Input Voltage
Level Test
VADP < VCHR_TH
No
Figure 2: AAT3670 Operational Flow Chart.
3670.2008.04.1.5
www.analogictech.com
19
PRODUCT DATASHEET
AAT3670
BatteryManagerTM
1.6A Dynamic Battery Charger and Power Manager
Applications Information
The following equation may be used to approximate the
ADP charge reduction threshold above or below 4.5V:
AC Adapter/USB System Power Charging
Adapter Input Mode
Eq. 1: VADPCHR =
In the adapter mode, constant current charge levels up
to 1.6A may be programmed by the user. The AAT3670
system control will always select the adapter input over
the USB supply input when ever voltage is present on
the ADP pin. The ADP input will operate over a range
from 4.35V to 5.5V.
2.0V
(R12/[R12 + R11])
where R11 and R12 < 500kΩ.
VADP
The constant fast charge current for the adapter input
mode is set by the RADPSET resistor connected between the
ADPSET pin and ground. The battery preconditioning or
trickle charge current is fixed at 10% of the programmed
fast charge constant current level. Refer to Table 2 for
recommended RADPSET values for a desired constant current charge level. Battery charging states will be indicated via the STAT1 and STAT2 display LEDs. Please
refer to the Battery Charge Status Indication discussion
for further details on data reporting.
R11
ADP
850k
CHRADP
VCHR = 2.0V
R12
650k
ADP Charge Reduction
Under normal operation, the AAT3670 should be operated
from an adapter power source with a sufficient capacity
to supply the desired constant charge current plus any
additional load which may be placed on the source by the
operating system. In the event that the power source to
the ADP pin is unable to provide the programmed fast
charge constant current, or if the system under charge
must also share supply current with other functions, the
AAT3670 will automatically reduce the ADP fast charge
current level to maintain the integrity of the source supply, power the operating system, and charge the battery
cell with the remaining available current.
The ADP charge reduction system becomes active when
the voltage on the ADP input falls below the ADP charge
reduction threshold (VCHRADP), which is preset to 4.6V.
Should the input supply drop below the VCHRADP threshold,
the charge reduction system will reduce the fast charge
current level in a linear fashion until the voltage sensed
on the ADP input recovers to a point above the charge
reduction threshold voltage. The ADP charge reduction
threshold (VCHRADP) may be externally set to a value other
than 4.6V by placing a resistor divider network between
the ADP pin and ground with the center connected to the
CHRADP pin. The ADP charge reduction feature may be
disabled by shorting the CHRADP pin directly to the ADP
input pin.
20
Figure 3: Internal Equivalent Circuit for the
CHRADP Pin.
Adapter Input Charge Inhibit and Resume
The AAT3670 has an under-voltage lockout (UVLO) and
power on reset feature to protect the charger IC in the
event the input supply to the adapter pin drops below
the UVLO threshold. Under a UVLO condition, the charger will suspend the charging process. When power is
re-applied to the adapter pin or the UVLO condition
recovers, the system charge control will asses the state
of charge on the battery cell and will automatically
resume charging in the appropriate mode for the condition of the battery.
USB Input Mode
The AAT3670 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 mode
provides two programmable fast charge levels, USB high
(USBH) and USB low (USBL). The USBH mode can be set
as high as 900mA; however for most applications utilizing a USB port as the source supply, 500mA is the typical
www.analogictech.com
3670.2008.04.1.5
PRODUCT DATASHEET
AAT3670
BatteryManagerTM
1.6A Dynamic Battery Charger and Power Manager
default USBH value and USBL is subsequently set for
100mA. In the USBL fast charge mode, the constant
charging current is set to 20 percent of the programmed
USBH. More simply put, the USBL low fast charge level
= USBH divided by five. The USBH or USBL modes may
be externally selected by USB select pin (USBSEL).
The following equation may be used to approximate a
USB charge reduction threshold below 4.5V:
In the USBH mode, the battery cell preconditioning or
trickle charge current is fixed at 10 percent of the programmed fast charge constant current. In the USBL mode,
the trickle charge current is only reduced to 50 percent of
the programmed fast charge constant current level.
where R1 and R2 < 1MΩ
Eq. 2: VUSBCHR =
VUSB
When the USBSEL pin is connected to a logic high level,
the USBH level will be active. Conversely, when USBSEL
is pulled to a logic low level (ground) the USBL level will
be used for fast charging. Refer to Table 2 for the recommended RUSBSET value to program the desired USB input
constant current charge levels.
R1
2.0V
(R2/[R2 + R1])
USB
1.0M
CHRUSB
VCHR = 2.0V
R2
800k
USB Charge Reduction
In many instances, product system designers have an
issue of not knowing the real properties of a potential
USB port to be used to supply power to the battery charger. Typical powered USB ports commonly found on
desktop and notebook PCs should supply up to 500mA.
In the event a USB port being used to supply the charger
is unable to provide the programmed fast charge current, or if the system under charge must also share supply current with other functions causing an overload to
the USB port, the AAT3670 will automatically reduce
USB fast charge current to maintain port integrity and
protect the host system.
The USB charge reduction system becomes active when
the voltage on the USB input falls below the USB charge
reduction threshold (VCHRUSB), which is typically 4.5V.
Regardless of which USB charge function is selected
(USBH or USBL), the charge reduction system will
reduce the fast charge current level in a linear fashion
until the voltage sensed on the USB input recovers
above the charge reduction threshold voltage. The USB
charge reduction threshold (VCHRUSB) may be externally
set to a value lower than 4.5V by placing a resistor
divider network between VUSB and ground with the center connected to the CHRUSB pin. The USB charge
reduction feature may be disabled by shorting the
CHRUSB pin directly to the USB input pin.
3670.2008.04.1.5
Figure 4: Internal Equivalent Circuit for the
CHRUSB Pin.
USB Input Charge Inhibit and Resume
The AAT3670 under-voltage lockout (UVLO) and poweron reset feature will function when the USB input pin
voltage level drops below the UVLO threshold. At this
point the charger will suspend charging. 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.
End of Charge Termination
The AAT3670 provides a user-programmable charge termination current at the end of the charge cycles. When
the battery cell voltage as sensed by the BATS pin reaches 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 (EOC)
current, the charge cycle is complete and the charge
controller terminates the charging process.
www.analogictech.com
21
PRODUCT DATASHEET
AAT3670
BatteryManagerTM
1.6A Dynamic Battery Charger and Power Manager
The charge termination current is user programmed by
the value of RTERM, which is connected between the TERM
pin and ground. Use the values listed in Table 1 to set
the desired charge termination current. The programmed
charge termination current will remain at the same set
level regardless of which fast charge ADP, USBH or USBL
constant current mode is selected.
ITERM (mA)
RTERM (kΩ)
320
174
125
95
77
64
58
50
49
42
37
11.0
21.0
30.9
41.2
51.1
61.9
71.5
80.6
90.9
100.0
110.0
Table 1: Charge Termination Current
Programming Resistor Values.
If the desired end of charge termination current level is
not listed in Table 1, the TERM resistor value may be
calculated by the following equation:
For the Adapter input mode:
RTERM = K ·
The power to the system is supplied via the OUT pin. OUT
will source power from either the ADP or USB inputs when
an external power source is applied. When the battery
charging function is complete and the charging power
source is removed, the system will be powered from the
battery via Load Switch 3, referring to the AAT3670 block
diagram. The maximum current that can be supplied from
the ADP or USB inputs to a system load is bounded by the
user programmed ADPLIM and USBLIM level. If the current consumption from the system load exceeds that of
the ADP or USB input sources, the IC will draw current
from the battery to make up the difference as long as the
battery cell voltage remains above 2.9V. Power from the
battery to the OUT pin is controlled by the ENBAT function. When the ENBAT is disabled the leakage current
from the battery to the load is less than 1µA.
Battery Connection and
Battery Voltage Sensing
Battery Connection
The single cell Li-ion battery should be connected
between the BAT pin and ground. The internal load
switching network will connect the battery to the system
load and apply the charging current.
Battery Voltage Sensing
⎛ VTERM⎞
⎝ ICC ⎠
Where:
K = KI_TERM = 2000
VTERM = 2V
ICC = Fast charge constant current
The constants K and VTERM are specified in the Typical
Characteristics section of this datasheet.
The end-of-charge termination current function can be
disabled by pulling the TERM pin high via connecting the
TERM pin to the BAT pin. In this state, the end-of-charge
function will be disabled and the battery will float charge
in the constant voltage mode indefinitely or until the cell
voltage is brought below the constant voltage threshold.
22
System Power Output
The BATS pin is provided to employ an accurate voltage
sensing capability to measure the terminal voltage at the
battery cell being charged. This function reduces measured battery cell voltage error between the battery
terminal and the charge control IC. The AAT3670 charge
control circuit will base charging mode states upon the
voltage sensed at the BATS pin. The BATS pin must be
connected to the battery terminal for correct operation.
If the battery voltage sense function is not needed, the
BATS pin should be terminated directly to the BAT pin. If
there is concern of the battery sense function inadvertently becoming an open circuit, the BATS pin may be
terminated to the BAT pin using a 10kΩ resistor. Under
normal operation, the connection to the battery terminal
will be close to 0Ω; if the BATS connection becomes an
open circuit, the 10kΩ will provide feedback to the BATS
pin from the BAT connection will a 1mV or less loss in
sensed voltage accuracy.
www.analogictech.com
3670.2008.04.1.5
PRODUCT DATASHEET
AAT3670
1.6A Dynamic Battery Charger and Power Manager
Enable
The AAT3670 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 AAT3670 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.
Battery Enable
Since the AAT3670 provides battery power switching as
well as charging function, a battery enable pin (ENBAT)
is provided so the power from the battery via the BAT
pin to the OUT pin may be externally controlled. The
ENBAT function allows the user to control power to the
systems regardless of charging state, input power
source, or charge enable (EN) state.
It may be desirable for some system designs to disconnect the battery from the load during charging. This may
be accomplished by pulling the ENBAT pin low, while the
device is enabled for charging (EN high).
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 or USBSET pins
and ground. The accuracy of the fast charge constant
current and the preconditioning trickle charge current
are dominated by the tolerance of the set resistor used.
For this reason, 1% tolerance metal film resistors are
recommended for this set resistor function.
Fast charge constant current levels from 50mA to 1.6A
may be set by selecting the appropriate resistor value
from Table 2. The RADPSET resistor should be connected
between the ADPSET pin and ground.
The USB input fast charge constant current charge control provides up to 900mA of charge current and is set
in the USBH mode. The USBSEL pin is used to select the
high or low charge current levels in the USB charge
mode. When the USBSEL pin is pulled to a voltage level
above the VUSBSEL(H) threshold, the USBH current level will
be selected. Conversely, this pin should be pulled below
3670.2008.04.1.5
the VUSBSEL(L) threshold to enable the USBL charge level;
the USBL charge current will be set to 20% of the set
USBH level. For typical USB charging applications, the
USBH and USBL functions are fixed for 500mA and
100mA USB fast charge levels. However, the charge
level of USBH may be set from 50mA to 900mA and
USBL will in turn be fixed at 20% of the USBH level
depending upon the system design requirements for a
given USB charge application. Refer to Table 2 and
Figure 5 for recommended RUSBSET values.
ICC
(mA)
ADP
RSET (kΩ)
USBH
RSET (kΩ)
USBL
RSET (kΩ)
50
90
100
150
200
250
300
400
500
650
800
900
1000
1200
1500
1600
1300
681
590
412
309
249
205
154
121
93.1
73.2
64.9
57.6
48.7
38.3
34.8
750
453
383
249
187
150
124
90.9
71.5
54.9
43.2
38.3
150
80.6
71.5
47.5
34.8
Table 2: RSET Values.
1800
1600
IFASTCHARGE (mA)
BatteryManagerTM
1400
1200
USBH
1000
ADP
800
600
USBL
400
200
0
10
100
1000
10000
RSET (kΩ
Ω)
Figure 5: Fast Charge Current vs. Set Resistor
(VIN = 5V; VBAT = 3.5V).
www.analogictech.com
23
PRODUCT DATASHEET
AAT3670
BatteryManagerTM
1.6A Dynamic Battery Charger and Power Manager
If the desired current charge current level is not listed in
Table 2, the ADPSET and USBSET resistor values may be
calculated by the following equations:
For the Adapter input mode:
RADPSET = K ·
⎛ VADPSET⎞
⎝ ICC ⎠
Where:
Programmable Watchdog Timer
K = KI_CCADP = 29300
VADPSET = 2V
ICC = Fast Charge Constant Current
The AAT3670 contains a watchdog timing circuit which
operates only in adapter charging 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 45 minutes. When the device transitions
to the trickle charge to the fast charge constant current
mode and then to the constant voltage mode, the timing
counter is reset and will time out after 3 hours for each
mode.
For the USB input mode:
RUSBSET = K ·
⎛ VUSBSET⎞
⎝ ICC ⎠
Where:
K = KI_CCUSBH = 17900 (USBH)
K = KI_CCUSBL = 3600 (USBL)
VUSBSET = 2V
ICC = Fast Charge Constant Current
Summary for a 0.1µF used for the timing capacitor:
All constants K and VADP/USBSET are specified in the Typical
Characteristics section of this datasheet.
Protection Circuitry
Thermal Loop Control
Due to the integrated nature of the linear charging control pass devices for both the adapter and USB modes, a
special thermal loop control system has been employed
to maximize charging current under all operating conditions. The thermal management system measures the
internal circuit die temperature and reduces the charge
current when the device exceeds a preset internal temperature control threshold. Once the thermal loop control becomes active, the constant charge current is initially reduced by a factor of 0.44.
The initial thermal loop current can be estimated by the
following equations:
In ADP mode: ITLOOP = ICCADP · 0.44
In USB mode: ITLOOP = ICCUSBH · 0.44
24
The thermal loop control re-evaluates the internal die
temperature every three seconds and adjusts the fast
charge current back up in small steps up to the full fast
charge current level or until an equilibrium current is
discovered and maximized for the given ambient temperature condition. In this manner, the thermal loop
controls the system charge level. The AAT3670 will
always provide the highest possible level of constant current in the fast charge mode for any given ambient temperature condition.
Trickle Charge (TC) time out = 45 minutes
Fast Charge Constant Current (CC) time out = 3 hours
Constant Voltage (VC) mode time out = 3 hours
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 time
of the CC + CV modes would be doubled. The corresponding trickle charge time out time would be the combined CC + VC time divided by 8.
If the programmable watchdog timer function is not
needed it may be disabled the terminating the CT pin to
ground. The CT pin should not be left floating or unterminated; this will cause errors in the internal timing
control circuit.
The charge timer control will suspend the timing count in
any given mode in the event a fault condition occurs.
Such fault conditions include digital thermal loop charge
current reduction, ADP or USB charge reduction, battery
temperature fault, and battery current sharing with the
output during the charging cycle. When the fault condition recovers, the counter will resume the timing function. The charge timer will automatically reset when the
AAT3670 enable pin is reset or cycled off and on.
www.analogictech.com
3670.2008.04.1.5
PRODUCT DATASHEET
AAT3670
BatteryManagerTM
1.6A Dynamic Battery Charger and Power Manager
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 determined by the capacitance value, a 10% tolerance or
better ceramic capacitor is recommended. Ceramic
capacitor materials such as X7R and X5R type are a
good choice for this application.
If the desired charge current limit level is not listed in
Table 3, the ADPLIM and USBLIM set resistor values may
be calculated by the following equations:
Over-Current Protection
K = KI_LIM_ADP = 27800
VADPLIM = 2V
ICC = Fast Charge Constant Current
The AAT3670 provides over-current protection to both
the battery and system output modes for both the ADP
and USB input sources.
The over-current protection threshold is user programmable and independent from the constant charge current
setting. The set resistor RADPLIM is connected between the
ADPLIM pin and ground to program the ADP power path
current limit up to 1.6A. The set resistor RUSBLIM is connected between the USBLIM pin and ground to program
the USB power path current limit up to 900mA. For both
the ADP and USB charge paths, the programmed constant
current fast charge level may not exceed the respective
ADPLIM and USBLIM set points. Refer to Table 3 for the
ADPLIM and USBLIM programming resistor values.
ICC (mA)
RADPLIM (kΩ)
RUSBLIM (kΩ)
50
90
100
150
200
250
300
400
500
650
800
900
1000
1200
1500
1600
1300
681
590
412
309
249
205
154
121
93.1
73.2
64.9
57.6
48.7
38.3
34.8
750
453
383
249
187
150
124
90.9
71.5
54.9
43.2
38.3
RADPLIM = K ·
⎛ VADPLIM⎞
⎝ ICC ⎠
Where:
For the USB input mode:
RUSBLIM = K ·
⎛ VUSBLIM⎞
⎝ ICC ⎠
Where:
K = KI_LIM_USBH = 17600 (USBH)
K = KI_LIM_USBL = 3500 (USBL)
VUSBLIM = 2V
ICC = Fast Charge Constant Current
All constants K and VADP/USBLIM are specified in the Typical
Characteristics section of this datasheet.
Over-Voltage Protection
An over-voltage event is defined as a condition where
the voltage on the BATS pin exceeds the maximum battery charge voltage and is set by the over-voltage protection threshold (VOVP). If an over-voltage condition
occurs, the AAT3670 charge control will shutdown the
device until voltage on the BATS pin drops below the
over-voltage protection threshold (VOVP). The AAT3670
will resume normal charging operation once the battery
over-voltage condition is removed. During an over-voltage event, the STAT2 LED will report a system fault.
Over-Temperature Shutdown
Table 3: Current Limit Programming
Resistor Values.
3670.2008.04.1.5
For the Adapter input mode:
The AAT3670 has a thermal protection control circuit
which will shut down charging functions should the internal die temperature exceed the preset thermal limit
threshold.
www.analogictech.com
25
PRODUCT DATASHEET
AAT3670
BatteryManagerTM
1.6A Dynamic Battery Charger and Power Manager
Battery Temperature Fault Monitoring
Status Indicator Display
In the event of a battery over-temperature condition, the
charge control will turn off the internal charge path regulation device and report the fault condition via the STAT2
display LED. After the system recovers from a temperature fault, the device will resume charging operation. The
AAT3670 checks battery temperature before starting the
charge cycle, as well as during all stages of charging.
System charging status may be displayed using one or
two LEDs in conjunction with the STAT1 and STAT2 pins
on the AAT3670. These two pins are simple switches to
connect the status 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 for the various charging
states. Refer to Table 4 for LED display definitions.
Typically, batteries employ the use of a negative temperature coefficient (NTC) thermistor that is integrated
into the battery package. Most commonly used NTC
thermistors used in battery packs are approximately
10kΩ at room temperature (25°C). However, the AAT3670
TS pin, in conjunction with the VTS pin, permits the use
of almost any value of NTC thermistor.
There are two pins associated with the battery temperature sensing function, TS and VTS. The battery pack
thermistor should be connected between the TS pin and
ground. The VTS pin is provided to allow the user to
program battery temperature sense thresholds depending upon the value of the NTC thermistor used in a given
battery pack. A resistor (RT) connected between the VTS
pin and the TS pin will set a bias for the NTC thermistor
function. The TS function has been designed such that a
default NTC thermistor value of 10kΩ will then require a
10k resistor for RT. To determine the actual operating
temperature window for the the NTC thermistor and the
TS pin, one must first specify the NTC thermistor to be
used, then refer to the thermistor datasheet to determine its characteristics.
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 · VVTS
and the TS2 threshold = 0.72 · VVTS. The VTS pin is
capable of sourcing up to 2mA.
If the use of the battery temperature sense function is
not required, it may be disabled by disconnecting the
VTS pin from the TS pin and terminating the TS pin to
ground. The VTS pin can be left floating.
VTS
0.72 · VVTS
RT
TS
Battery Cold Fault
+
RNTC
Battery Hot Fault
T
+
0.30 · VVTS
Figure 6: Battery Temperature Sense Circuit.
VTS
RT
0.72V
Battery Cold Fault
TS
+
RADJ
0.30V
RNTC
Battery Hot Fault
+
T
Battery Charge Status Indication
The AAT3670 indicates the status of the battery under
charge using 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.
26
Figure 7: Battery Temperature Sense Circuit with
Externally Adjusted Window Threshold.
www.analogictech.com
3670.2008.04.1.5
PRODUCT DATASHEET
AAT3670
BatteryManagerTM
1.6A Dynamic Battery Charger and Power Manager
Event Description
STAT1
End of Charge (TERM Current Reached in CVM), Battery OV, Timeout, or Charge Disabled
No Battery (With Charge Enabled)
Battery Charging (Including Suspended Charging Due to Battery OT/UT, or Device OT )
OFF
Flash (1Hz, 40% duty)
ON
Event Description
STAT2
Charge Disabled, No Battery, End of Charge, or Charging Without Faults
Faults (Battery OV/OT/UT, or Device OT) or Timeout
OFF
ON
Table 4: LED Status Indicator (STATx Pulled Up to a Voltage Source with Resistors and LED).
The LED anodes should be connected to USB, ADP, BAT,
or OUT depending upon the system design requirements. The LEDs should be biased with as little current
as necessary to create reasonable illumination. A ballast
resistor should be placed between the status LED cathodes and the STAT1/2 pins. LED current consumption
will add to the over thermal power budget for the device
package, hence it is good reason to keep the LED drive
current to a minimum. 2mA should be sufficient to drive
most common 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:
Eq. 3: RB(STAT1/2) =
Example: RB(STAT2) = (3.6V - 3.2V) 2mA = 200Ω
Note: Green LED forward voltage (VF) is typically 3.2V @
2mA.
No Battery Present Indication
If the AAT3670 charger IC is powered and enabled from
either the ADP or USB input, yet no battery is connected
to the BAT and BATS pins, the STAT1 LED will flash at a
1Hz rate with an approximate 40% duty cycle when a
10µF capacitor is connected between the BAT pin and
ground. The flash rate of the STAT1 LED can be adjusted
by changing the value of the battery output (BAT pin)
capacitor. If the capacitor value is increased above 20µF,
the no battery detect flashing function will be defeated.
The flash rate of the no battery detect function may be
approximated by the following equation:
(VADP - VF(LED))
ILED(STAT1/2)
Example: RB(STAT1) = (5.5V - 2.0V) 2mA = 1.75kΩ
Note: Red LED forward voltage (VF) is typically 2.0V @
2mA.
(VUSB - VF(LED))
ILED(STAT1/2)
Example: RB(STAT2) = (5.0V - 3.2V) 2mA = 900Ω
Note: Green LED forward voltage (VF) is typically 3.2V @
2mA.
For connection to the BAT supply:
Eq. 5: RB(STAT1/2) =
3670.2008.04.1.5
(VBAT - VF(LED))
ILED(STAT1/2)
I·T
V
Where:
C = Capacitor value
I = Start up source current from the BAT pin = 5µA
V = Difference voltage between the end of charge voltage and the battery recharge threshold = 0.2V
T = Rate of LED flashing in seconds
For connection to the USB supply:
Eq. 4: RB(STAT1/2) =
Eq. 6: C =
Thermal Considerations
The AAT3670 is available in a 4x4mm 24-pin QFN package which can provide up to 2.0W of power dissipation
when it is properly bonded to a printed circuit board, but
can achieve a maximum thermal resistance of 37°C/W
with printed circuit board enhancement. 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 ambi-
www.analogictech.com
27
PRODUCT DATASHEET
AAT3670
BatteryManagerTM
1.6A Dynamic Battery Charger and Power Manager
ent 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 the calculated:
Eq. 7: PD = [(VIN - VBAT) · ICC + (VIN · IOP) + (IOUT2 · RDS(ON))
Given:
VADP = 5.0V
VBAT = 3.0V
ICC = 1A
IOP = 0.75mA
TJ = 110°C
θJA = 37°C/W
IOUT = 0
RDS(ON) = 0.4Ω
Using Equation 7, calculate the device power dissipation
for the stated condition:
Where:
PD
VIN
VBAT
ICC
IOP
IOUT
RDS(ON)
= Total power dissipation by the device
= either VADP or VUSB, depending on which mode is
selected
= Battery voltage as seen at the BAT pin
= Maximum constant fast charge current programmed for the application
= Quiescent current consumed by the charger IC
for normal operation
= Load current to system from the OUT pin
= On-resistance of load switch between ADP or
USB and OUT
Next, the maximum operating ambient temperature for
a given application can be estimated based on the thermal resistance of the 4x4 QFN package when sufficiently
mounted to a PCB layout and the internal thermal loop
temperature threshold.
= 2.00375W
The maximum ambient temperature before the AAT3670
thermal loop becomes active can now be calculated
using Equation 8:
Eq. 10: TA = 110°C - (37°C/W · 2.00375W)
= 35.86°C
Therefore, under the stated conditions for this worstcase power dissipation example, the AAT3670 will enter
the thermal loop and lower the fast charge constant current when the ambient operating temperature rises
above 35.86°C.
Capacitor Selection
Eq. 8: TA = TJ - (θJA · PD)
Input Capacitor
Where:
TA = Ambient temperature in °C
TJ = Maximum device junction temperature below the
thermal loop threshold
PD = Total power dissipation by the device
θJA = Package thermal resistance in °C/W
Example:
For an application where the fast charge current for the
adapter mode is set to 1A, VADP = 5.0V, and the worstcase battery voltage at 3.0V with the system load disabled, what is the maximum ambient temperature where
the thermal limiting will become active?
28
Eq. 9: PD = (5.0V - 3.0V)(1A) + (5.0V · 0.75mA) + (02 · 0.4Ω)
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 AAT3670 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” in. Likewise, a
10µF or greater input capacitor is recommended for the
www.analogictech.com
3670.2008.04.1.5
PRODUCT DATASHEET
AAT3670
BatteryManagerTM
1.6A Dynamic Battery Charger and Power Manager
USB input to help buffer the effects of USB source power
switching, noise and input cable impedance.
Printed Circuit Board
Layout Considerations
Output Capacitor
For the best results, it is recommended to physically place
the battery pack as close as possible to the AAT3670 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 AAT3670 QFN
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. Refer to the AAT3670
evaluation board for a good layout example.
The AAT3670 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
AAT3670 is to be used in applications where the battery
can be removed from the charger, such as with the case
with desktop charging cradles, an output capacitor
greater than 10µF, but less than 20µF, may be required
to retard the device from cycling on and off when no
battery is present.
J6
J2
J8
USB
USB
2 1
USBSEL
1 2 3 4 5
R13
R12
TBD
TBD
D1
1 2 3
R11
R10
1K
1K
C2
10µF
D3A
SOT-23
D2
J1
1
2
3
D3B
CT
ADP
C1
10µF
STAT2
N/C
STAT1
USB
19
OUT
CT
18
EN
17
C4
0.01µF
R9
OUT
TERM
16
4
BAT
GND
15
5
BAT
USBSET
14
R8
6
ADP
ADPSET
13
71.5K
R7
USBLIM
ENBAT
J3
3
VTS
1
2
20
ADPLIM
C3
10µF
BAT
J4
21
CHRADP
1
2
3
C5
10µF
USBSEL
22
BATS
OUT
J5
2
ENBAT
1
1
2
23
TS
J7
24
CHRUSB
U1
71.5K
1
2
3
ENABLE
57.6K
AAT3670
7
8
9
10
11
12
R1
100K
R2
100K
R3 R4 R5
R6
TBD TBD 34.8K 39.2K
TS
Figure 8: AAT3670 Evaluation Board Schematic.
3670.2008.04.1.5
www.analogictech.com
29
PRODUCT DATASHEET
AAT3670
BatteryManagerTM
1.6A Dynamic Battery Charger and Power Manager
Figure 9: AAT3670 Evaluation Board Top Side Layout.
Figure 10: AAT3670 Evaluation Board Bottom Side Layout.
30
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3670.2008.04.1.5
PRODUCT DATASHEET
AAT3670
BatteryManagerTM
1.6A Dynamic Battery Charger and Power Manager
Ordering Information
Package
Marking1
Part Number (Tape and Reel)2
QFN44-24
TFXYY
AAT3670ISK-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/about/quality.aspx.
Package Information3
QFN44-24
0.4 ± 0.05
24
1
2.7 ± 0.05
0.5 BSC
4.000 ± 0.050
19
18
R0.030Max
13
6
12
4.000 ± 0.050
0.300 × 45°
Pin 1 Identification
0.305 ± 0.075
Pin 1 Dot By Marking
7
2.7 ± 0.05
Top View
0.214 ± 0.036
0.900 ± 0.050
0.025 ± 0.025
Bottom View
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.
Advanced Analogic Technologies, Inc.
3230 Scott Boulevard, Santa Clara, CA 95054
Phone (408) 737-4600
Fax (408) 737-4611
© 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. Except as provided in AnalogicTech’s terms and
conditions of sale, AnalogicTech assumes no liability whatsoever, and AnalogicTech disclaims any express or implied warranty relating to the sale and/or use of AnalogicTech products including liability or warranties
relating to fitness for a particular purpose, merchantability, or infringement of any patent, copyright or other intellectual property right. In order to minimize risks associated with the customer’s applications, adequate
design and operating safeguards must be provided by the customer to minimize inherent or procedural hazards. Testing and other quality control techniques are utilized to the extent AnalogicTech deems necessary to
support this warranty. Specific testing of all parameters of each device is not necessarily performed. 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.
3670.2008.04.1.5
www.analogictech.com
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