TI1 LP3947ISD-09/NOPB Lp3947 usb/ac adaptor, single cell li-ion battery charger ic Datasheet

LP3947
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SNVS298B – NOVEMBER 2004 – REVISED APRIL 2013
LP3947 USB/AC Adaptor, Single Cell Li-Ion Battery Charger IC
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FEATURES
DESCRIPTION
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The LP3947 is a complete charge management
system that safely charges and maintains a Li-Ion
battery from either USB power source or AC adaptor.
In USB mode, the LP3947 supports charging in low
power or high power mode. Alternatively, the LP3947
can take charge from AC adaptor. In both USB and
AC adaptor modes, charge current, battery regulation
voltage, and End of Charge (EOC) point can be
selected via I2C™ interface. The LP3947 can also
operate on default values that are pre-programmed in
the factory. The battery temperature is monitored
continuously at the Ts pin to safeguard against
hazardous charging conditions. The charger also has
under-voltage and over-voltage protection as well as
an internal 5.6 hr timer to protect the battery. The
pass transistor and charge current sensing resistor
are all integrated inside the LP3947.
1
23
Supports USB Charging Scheme
Integrated Pass Transistor
Near-Depleted Battery Preconditioning
Monitors Battery Temperature
Built-In 5.6 Hour Timer
Under Voltage and Over Voltage Lockout
Charge Status Indicators
Charge Current Monitor Analog Output
LDO Mode Operation can source 1 Amp
Continuous Over Current/Temperature
Protection
APPLICATIONS
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Cellular Phones
PDAs
Digital Cameras
USB Powered Devices
Programmable Current Sources
The LP3947 operates in four modes: pre-qualification,
constant current, constant voltage and maintenance
modes. There are two open drain outputs for status
indication. An internal amplifier readily converts the
charge current into a voltage. Also, the charger can
operate in an LDO mode providing a maximum of 1.2
Amp to the load.
KEY SPECIFICATIONS
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1% Charger Voltage Accuracy Over
0°C ≤ TJ ≤ 85°C
4.3V to 6V Input Voltage Range
100 mA to 750 mA Charge Current Range, in
Charger Mode
100 mA to 500 mA Charge Current Range, in
USB Mode
WSON Package Power Dissipation:
2.7W at TA = 25°C
TYPICAL APPLICATION CIRCUIT
USB Power Source
4.3V to 5.5V
CHG-IN
To
System
Supply
BATT
1 PF
Li-Ion
10 PF
VBSense
LP3947
CHG
RT
TS
VT
RS
EOC
Diff-Amp
ISEL
SCL
MODE
SDA
EN
GND
More Application Circuit can be found in APPLICATION NOTES.
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
I C is a trademark of Philips Semiconductor Corporation.
All other trademarks are the property of their respective owners.
2
2
3
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2004–2013, Texas Instruments Incorporated
LP3947
SNVS298B – NOVEMBER 2004 – REVISED APRIL 2013
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These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
CONNECTION DIAGRAMS AND PACKAGE MARK INFORMATION
14
13
12
11
10
9
8
1
2
3
4
5
6
7
Figure 1. Package Number NHL0014B (Top View)
PIN DESCRIPTIONS
Pin #
Name
Description
1
EN
Charger Enable Input. Internally pulled high to CHG-IN pin. A HIGH enables the charger and a LOW disables the
charger.
2
SCL
I2C serial Interface Clock input.
3
SDA
I2C serial Interface Data input/out.
4
BATT
Battery supply input terminal. Must have 10 µF ceramic capacitor to GND
5
VT
Regulated 2.78V output used for biasing the battery temperature monitoring thermistor.
6
VBSENSE
Battery Voltage Sense connected to the positive terminal of the battery.
7
MODE
Select pin between AC adaptor and USB port. A LOW sets the LP3947 in USB port and a HIGH sets it in the AC
adaptor.
8
Diff-Amp
Charge current monitoring differential amplifier output. Voltage output representation of the charge current.
9
Ts
Multi function pin. Battery temperature monitoring input and LDO/Charger mode.
Pulling this pin to VT, or removing the thermistor by physically disconnecting the battery, sets the device in LDO
mode.
10
EOC
Active Low Open Drain Output. Active when USB port or AC adaptor is connected and battery is fully charged. For
more information, refer to “LED Charge Status Indicators” section.
11
GND
Ground
12
CHG
Active Low Open Drain Output. Active when USB port or AC adaptor is connected and battery is being charged.
For more information, refer to “LED Charge Status Indicators” section.
13
ISEL
Control pin to switch between low power (100 mA) mode and high power (500 mA) mode in USB mode. This pin
is pulled high internally as default to set the USB in 100 mA mode. This pin has to be externally pulled low to go
into 500 mA mode.
14
CHG-IN
Charger input from a regulated, current limited power source. Must have a 1 µF ceramic capacitor to GND
Table 1. ORDERING INFORMATION
Part Number
Default Options
Top-Side Markings
LP3947ISD-09
ICHG = 500 mA
L00061B
VBATT = 4.1V
EOC = 0.1C
LP3947ISD-51
ICHG = 500 mA
L00062B
VBATT = 4.2V
EOC = 0.1C
2
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LP3947 FUNCTIONAL BLOCK DIAGRAM
ISEL
Mode
SDA
CHG
ON/OFF
2
I C and Digital
Control
SCL
LED
Driver
EOC
EN
RSENSE
CHG-IN
BATT
+
Diff Amp
Power
FET
Control
VT
Charger
control
LDO
Mode
Vref
+
-
TS
UTLO
LDO
Error
Amp
+
OTLO
+
-
ABSOLUTE MAXIMUM RATINGS
(1) (2)
If Military/Aerospace specified devices are required, contact the Texas Instruments Semiconductor Sales Office/
Distributors for availability and specifications.
−0.3V to +6.5V
CHG-IN
All pins except GND and CHG-IN
(3)
−0.3V to +6V
Junction Temperature
150°C
Storage Temperature
−40°C to +150°C
(4)
1.89W
Power Dissipation
ESD (5)
Human Body Model
Machine Model
(1)
(2)
(3)
(4)
(5)
2 kV
200V
All voltages are with respect to the potential at the GND pin.
Absolute Maximum Ratings are limits beyond which damage to the device may occur. Operating Ratings are conditions under which
operation of the device is ensured. Operating Ratings do not imply verified performance limits. For specified performance limits and
associated test conditions, see the Electrical Characteristics tables.
Caution must be taken to avoid raising pins EN and VT 0.3V higher than VCHG-IN and raising pins ISEL, MODE, SCL and SDA 0.3V
higher than VBATT.
The Absolute Maximum power dissipation depends on the ambient temperature and can be calculated using the formula
MM P = (TJ – TA)θJA,
where TJ is the junction temperature, TA is the ambient temperature, and θJA is the junction-to-ambient thermal resistance. The 1.89W
rating appearing under Absolute Maximum Ratings results from substituting the Absolute Maximum junction temperature, 150°C, for TJ,
80°C for TA, and 37°C/W for θJA. More power can be dissipated safely at ambient temperatures below 80°C. Less power can be
dissipated safely at ambient temperatures above 80°C. The Absolute Maximum power dissipation can be increased by 27 mW for each
degree below 80°C, and it must be de-rated by 27 mW for each degree above 80°C.
The human-body model is used. The human-body model is 100 pF discharged through 1.5 kΩ.
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RECOMMENDED OPERATING CONDITIONS
(1) (2)
CHG-IN
0.3V to 6.5V
EN, ISEL, MODE, SCL, SDA, VT (3)
0V to 6V
−40°C to +125°C
Junction Temperature
−40°C to +85°C
Operating Temperature
Thermal Resistance θJA
Maximum Power Dissipation
(1)
37°C/W
(4)
1.21W
Absolute Maximum Ratings are limits beyond which damage to the device may occur. Operating Ratings are conditions under which
operation of the device is ensured. Operating Ratings do not imply verified performance limits. For specified performance limits and
associated test conditions, see the Electrical Characteristics tables.
All voltages are with respect to the potential at the GND pin.
Caution must be taken to avoid raising pins EN and VT 0.3V higher than VCHG-IN and raising pins ISEL, MODE, SCL and SDA 0.3V
higher than VBATT.
Like the Absolute Maximum power dissipation, the maximum power dissipation for operation depends on the ambient temperature. The
1.21W rating appearing under Operating Ratings results from substituting the maximum junction temperature for operation, 125°C, for
TJ, 80°C for TA, and 37°C/W for θJA into (1) above. More power can be dissipated at ambient temperatures below 80°C. Less power can
be dissipated at ambient temperatures above 80°C. The maximum power dissipation for operation can be increased by 27 mW for each
degree below 80°C, and it must be de-rated by 27 mW for each degree above 80°C.
(2)
(3)
(4)
ELECTRICAL CHARACTERISTICS
Unless otherwise noted, VCHG-IN = 5V, VBATT = 4V, CCHG-IN = 1 µF, CBATT = 10 µF. Typical values and limits appearing in normal
type apply for TJ = 25°C. Limits appearing in boldface type apply over the entire junction temperature range for operation, TJ
= −40°C to +85°C. (1) (2) (3)
Symbol
Parameter
Conditions
Typ
Limit
Min
Max
4.5
6
4.3
6
Units
VCC SUPPLY
VCHG-IN
Input Voltage Range
VUSB
ICC
Quiescent Current
VOK-TSHD
Adaptor OK Trip Point (CHG-IN)
VUVLO-TSHD
Under Voltage Lock-Out Trip Point
VCHG-IN ≤ 4V
2
20
EOC = Low, adaptor connected, VBATT =
4.1V
50
150
VCHG-IN –VBATT (Rising)
60
VCHG-IN –VBATT (Falling)
VOVLO-TSHD
Over Voltage Lock-Out Trip Point
Thermal Shutdown Temperature
V
µA
mV
50
mV
VCHG-IN (Rising)
3.95
3.6
4.3
V
VCHG-IN (Falling)
3.75
3.4
4.1
V
VCHG-IN (Rising)
5.9
VCHG-IN (Falling)
5.7
(2)
Thermal Shutdown Hysteresis
V
160
°C
20
BATTERY CHARGER
ICHG
Fast Charge Current Range
Fast Charge Current Accuracy
IPRE-CHG
(1)
(2)
(3)
4
Pre-Charge Current
ISEL = High, In USB Mode
100
ISEL = Low, In USB Mode
500
mA
In AC Adaptor Mode
100
750
ICHARGE = 100 mA or 150 mA
−20
+20
ICHARGE ≥ 200 mA
−10
+10
%
VBATT = 2V
45
70
mA
mA
All limits are specified. All electrical characteristics having room-temperature limits are tested during production with TJ = 25°C. All hot
and cold limits are specified by correlating the electrical characteristics to process and temperature variations and applying statistical
process control.
Specified by design.
LP3947 is not intended as a Li-Ion battery protection device, any battery used in this application should have an adequate internal
protection.
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ELECTRICAL CHARACTERISTICS (continued)
Unless otherwise noted, VCHG-IN = 5V, VBATT = 4V, CCHG-IN = 1 µF, CBATT = 10 µF. Typical values and limits appearing in normal
type apply for TJ = 25°C. Limits appearing in boldface type apply over the entire junction temperature range for operation, TJ
= −40°C to +85°C. (1) (2) (3)
Symbol
Parameter
Conditions
100 mA to 450 mA, 0.1C EOC Only
Typ
(4)
Limit
Max
−10
+10
mA
%
IEOC
End of Charge Current Accuracy
−20
+20
VBATT
Battery Regulation Voltage (For 4.1V
Cell)
TJ = 0°C to +85°C
4.1
4.059
4.141
TJ = −40°C to +85°C
4.1
4.038
4.162
Battery Regulation Voltage (For 4.2V
Cell)
TJ = 0°C to +85°C
4.1
4.158
4.242
TJ = −40°C to +85°C
4.2
4.137
4.263
VCHG-Q
Full Charge Qualification Threshold
VBATT Rising, Transition from Pre-Charge
to Full Current
3.0
VBAT-RST
Restart Threshold Voltage
(For 4.1V Cell)
VBATT Falling, Transition from EOC, to PreQualification State
3.9
3.77
4.02
Restart Threshold Voltage
(For 4.2V Cell)
VBATT Falling, Transition from EOC, to PreQualification State
4.00
3.86
4.12
500 mA to 750 mA, All EOC Points
RSENSE
Internal Current Sense Resistance
(2)
tOUT
Diff-Amp Output
Charger Time Out
VOL
Low Level Output Voltage
V
120
mΩ
1.2
ICHG = 50 mA
0.583
ICHG = 100 mA
0.663
ICHG = 750 mA
1.790
TJ = 0°C to 85°C
5.625
4.78
6.42
TJ = −40°C to +85°C
5.625
4.5
6.75
EOC, CHG Pins each at 9 mA
V
V
Internal Current Sense Resistor Load
Current
ICHGMON
Units
Min
A
V
100
Hrs
mV
TEMPERATURE SENSE COMPARATORS
VUTLO
VOTLO
Low Voltage Threshold
High Voltage Threshold
VLDO
LDO Mode Voltage Threshold
VT
Voltage Output
Voltage at Ts Pin, Rising
2.427
Voltage at Ts Pin, Falling
2.369
Voltage at Ts Pin, Rising
1.470
Voltage at Ts Pin, Falling
1.390
Voltage at Ts Pin, % of VT
V
V
97
%
2.787
V
LDO MODE (Ts = HIGH)
VOUT
Output Voltage Regulation
ILOAD = 50 mA
4.10
ILOAD = 750 mA
4.06
V
LOGIC LEVELS
VIL
Low Level Input Voltage
EN, ISEL, MODE
VIH
High Level Input Voltage
EN, ISEL, MODE
2.0
IIL
Input Current
EN, ISEL = LOW
IIH
Input Current
(4)
0.4
V
−10
+10
µA
MODE = LOW
−5
+5
µA
EN, ISEL, MODE = HIGH
−5
+5
µA
V
The ±10 mA limits apply to all charge currents from 100 mA to 450 mA, to 0.1C End Of Charge (EOC). The limits increase proportionally
with higher EOC points. For example, at 0.2C, the End Of Charge current accuracy becomes ±20 mA.
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ELECTRICAL CHARACTERISTICS, I2C INTERFACE
Unless otherwise noted, VCHG-IN = VDD = 5V, VBATT = 4V. Typical values and limits appearing in normal type apply for TJ =
25°C. Limits appearing in boldface type apply over the entire junction temperature range for operation, TJ = −40°C to
+125°C. (1) (2) (3)
Symbol
VIL
Parameter
Conditions
Low Level Input Voltage
Typ
Limit
Min
Max
Units
SDA & SCL
(2)
0.4
0.3 VDD
V
VIH
High Level Input Voltage
SDA & SCL
(2)
0.7 VDD
VDD +0.5
V
VOL
Low Level Output Voltage
SDA & SCL
(2)
0
0.2 VDD
V
VHYS
Schmitt Trigger Input Hysteresis
SDA & SCL
(2)
0.1 VDD
V
FCLK
Clock Frequency
(2)
tHOLD
Hold Time Repeated START Condition
(2)
0.6
µs
tCLK-LP
CLK Low Period
(2)
1.3
µs
tCLK-HP
CLK High Period
(2)
0.6
µs
Set-Up Time Repeated START
Condition
(2)
0.6
µs
Data Hold Time
(2)
300
ns
tDATA-SU
Data Set-Up Time
(2)
100
ns
tSU
Set-Up Time for STOP Condition
(2)
0.6
µs
tTRANS
Maximum Pulse Width of Spikes that
must be Suppressed by the Input Filter
of both DATA & CLK Signals.
(2)
tSU
tDATA-HOLD
(1)
(2)
(3)
400
50
kHz
ns
All limits are specified. All electrical characteristics having room-temperature limits are tested during production with TJ = 25°C. All hot
and cold limits are specified by correlating the electrical characteristics to process and temperature variations and applying statistical
process control.
Specified by design.
LP3947 is not intended as a Li-Ion battery protection device, any battery used in this application should have an adequate internal
protection.
Prequalification to Fast
Charge transition
CC to CV transition
4.1V 0r 4.2V
1C
4.1V
Battery Voltage
Charge Current
3.9V
3V
Battery
Voltage
Battery
Current
End of Charge
Current
0.1C (Default)
50 mA
Time
RLED
GLED
ON
OFF
OFF
ON
Figure 2. Li-Ion Charging Profile
6
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APPLICATION NOTES
LP3947 CHARGER OPERATION
The LP3947 charge cycle is initiated with AC adaptor or USB power source insertion. If the voltage on the CHGIN pin meets under-voltage (VUVLO-TSHD), over-voltage (VOVLO-TSHD) requirements, and the Adaptor OK signal is
detected, then pre-qualification cycle begins (see Figure 2). In this cycle, a safe current level, less than 70mA, is
pumped into the battery while the voltage across the battery terminals is measured. Once this voltage exceeds
3.0V, the controller will initiate constant current fast charge cycle. If the CHG-IN pin is connected to an AC
adaptor, the default charge current is 500 mA and I2C interface can be used to program this parameter. If the
CHG-IN pin is connected to the USB port, constant current cycle will start with a default of 100 mA. During this
cycle, the 5.6 hr safety timer starts counting.
If the 5.6 hr safety timers times out during constant current cycle, charging is terminated. As the battery is
charged during constant current mode, the voltage across pack terminal increases until it reaches 4.2V (or 4.1V).
As soon as pack terminal reaches 4.2V (or 4.1V), the controller starts operating in constant voltage mode by
applying regulated VBATT voltage across the battery terminals. During this cycle, the charge current, ICHG,
continues to decrease with time and when it drops below 0.1C (default value), the EOC signal is activated
indicating successful completion of the charge cycle. The EOC current can be programmed to 0.1C, 0.15C, or
0.2C. The default value is 0.1C. After completing the full charge cycle, the controller will start the maintenance
cycle where battery pack voltage is monitored continuously. During the maintenance cycle, if the pack voltage
drops 200 mV below the termination voltage, charge cycle will be initiated providing that the wall adaptor is
plugged in and is alive.
Charging terminates when the battery temperature is out of range. For more explanation, please refer to Ts PIN.
The LP3947 with I2C interface allows maximum flexibility in selecting the charge current, battery regulation
voltage and EOC current. The LP3947 operates in default mode during power up. See I2C INTERFACE for more
detail.
When charging source comes from the USB port, charging starts with 100 mA (low power mode, ISEL = high).
The USB controller can set the ISEL pin low to charge the battery at 500 mA. A simple external circuit selects
between an AC adaptor or the USB port. The circuit is designed with priority given to the AC adaptor.
P-Ch
MOSFET
USB
Port
CHG-IN
To
System
Supply
BATT
1 PF
Li-Ion
10 PF
VBSense
RS
Wall
Adaptor
LP3947
1k
10k
CHG
TS
RT
VT
EOC
Diff-Amp
EN
SCL
ISEL
SDA
GND
Mode
Figure 3. LP3947 with External Switch
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4.3V < VCHG-IN < 6.0V
and
VBATT < VCHG-IN
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4.3V < VCHG-IN < 6V
VBATT > VCHG-IN
Ts t 2.7V
Charger Off
LED's Off
1.39V < Ts < 2.42V
LDO Mode
ICHG = 1.2A
VBATT = 4.1V*
RLED = On
GLED = Off
LED's Off
Pre-Qualification
Charge Current = 50 mA
1.39V<Ts<2.42V
?
N
Y
VBATT > 3.0V?
N
Y
Set Fast Charge Current = I
Start 5.6 hr Timer
Timer time out
Timer =
5.6 hr?
Charger = Off
Timer resets
RLED = ON
GLED = ON
Y
Disconnect
power at
CHG-IN pin to
restart charger
Maintenance Mode
Charger = Off
RLED = Off
GLED = On
N
1.39V<Ts<2.42V
?
N
1.39V<Ts<2.42V
?
Y
EN pin =
low?
VBATT < 3.9V
and
EN pin =
High?
N
Battery Temp
violation
Charger = Off
Timer resets
RLED = ON
GLED = ON
Y
N
N
Y
VBATT > = 4.1V*?
Y
N
N
1.39V<Ts<2.42V
?
Y
Y
Y
Constant Voltage Mode
VBATT = 4.1V *
1.39V<Ts<2.42V
?
N
VBATT > 3.0V?
N
Y
1.39V<Ts<2.42V
?
N
Y
Timer =
5.6 hr?
or
EN pin =
low?
Y
N
2
* Default Value. See "I C Interface" section.
N
IEOC < (0.1 x ICHG)*?
Y
Figure 4. LP3947 Charger Flow Chart
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CHARGE CURRENT SELECTION IN CONSTANT CURRENT MODE
In the AC adaptor mode, the LP3947 is designed to provide a charge current ranging from 100 mA to 750 mA, in
steps of 50 mA, to support batteries with different capacity ratings. The default value is 500 mA. No external
resistor is required to set the charge current in the LP3947. In the USB mode, the LP3947 will initially charge
with 100 mA (ISEL = high). By setting the ISEL pin low, charge current can be programmed to 500 mA. In
addition, with ISEL = low, the charge current can be programmed to different values via the I2C interface.
Table 2. Charge Current Selection in AC Adaptor/USB Mode
MODE Pin
AC Adaptor Mode
USB Mode
ISEL Pin
Functions
HIGH
HIGH
ISEL polarity is irrelevant. Default 500 mA charge current. Can be reprogrammed via
I2C.
HIGH
LOW
LOW
HIGH
100 mA charge current
LOW
LOW
Default 500 mA charge current. Can be reprogrammed via I2C.
BATTERY VOLTAGE SELECTION
The battery voltage regulation can be set to 4.1V or 4.2V by default. Please refer to Ordering Information for
more details.
END OF CHARGE (EOC) CURRENT SELECTION
The EOC thresholds can be programmed to 0.1C, 0.15C or 0.2C in the LP3947. The default value is 0.1C, which
provides the highest energy storage, but at the expense of longer charging time. On the other hand, 0.2C takes
the least amount of charging time, but yields the least energy storage.
CHARGE CURRENT SENSE DIFFERENTIAL AMPLIFIER
The charge current is monitored across the internal 120 mΩ current sense resistor. The differential amplifier
provides the analog representation of the charge current. Charge current can be calculated using the following
equation:
ICHG =
(VDIFF - 0.497)
1.655
(1)
Where voltage at Diff Amp output (VDIFF) is in volt, and charge current (ICHG) is in amps.
CHG-IN
1.74V
Batt
Diff-Amp
Output
RSense
120 m:
Diff-Amp
0.583V
750 mA
50 mA
Charge Current
Figure 5. Charge Current Monitoring Circuit (Diff-Amp)
Monitoring the Diff Amp output during constant voltage cycle can provide an accurate indication of the battery
charge status and time remaining to EOC. This feature is particularly useful during constant voltage mode. The
current sense circuit is operational in the LDO mode as well. It can be used to monitor the system current
consumption during testing.
LED CHARGE STATUS INDICATORS
The LP3947 is equipped with two open drain outputs to drive a green LED and a red LED. These two LEDs work
together in combinations to indicate charge status or fault conditions. Table 3 shows all the conditions.
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Table 3. LED Indicator Summary
RED LED
(CHG)
GREEN LED (EOC)
OFF
OFF
Charger Off
Charging Li Ion Battery
(1)
ON
OFF
Maintenance Mode
OFF
ON
Charging Li Ion Battery after Passing Maintenance Mode
OFF
ON
EN Pin = LOW
OFF
ON
LDO Mode
OFF
OFF
5.6 Hr Safety Timer Flag/Battery Temperature Violation
ON
ON
(1)
Charging Li Ion battery for the first time after VCHG-IN insertion.
Ts PIN
The LP3947 continuously monitors the battery temperature by measuring the voltage between the Ts pin and
ground. Charging stops if the battery temperature is outside the permitted temperature range set by the battery’s
internal thermistor RT and the external bias resistor RS. A 1% precision resistor should be used for RS. A curve 2
type thermistor is recommended for RT. The voltage across RT is proportional to the battery temperature. If the
battery temperature is outside of the range during the charge cycle, the LP3947 will suspend charging. As an
example, for a temperature range of 0°C to 50°C, a 10kΩ for the thermistor and a 4.1kΩ for Rs should be used.
When battery temperature returns to the permitted range, charging resumes from the beginning of the flow chart
and the 5.6 hr safety timer is reset. Refer to Figure 4. LP3947 Charger Flow Chart for more information.
In absence of the thermistor, Ts pin will be pulled high to VT and the LP3947 goes into LDO mode. In this mode,
the internal power FET provides up to 1.2 amp of current at the BATT pin. The LDO output is set to 4.1V or 4.2V,
depending on the programmed battery regulation voltage. When operating at higher output currents, care must
be taken not to exceed the package power dissipation rating. See “Thermal Performance of WSON Package”
section for more detail.
Table 4. Charger Status in Relation to Ts Voltage
Voltage on the Ts Pin
Charger Status
Ts ≥ 2.7V
LDO Mode
2.427v ≤ Ts < 2.7V
0V ≤ Ts ≤ 1.39V
Charger Off
1.39V < Ts < 2.427V
Charger On
LDO MODE
The charger is in the LDO mode when the Ts pin is left floating. This mode of operation is used primarily during
system level testing of the handset to eliminate the need for battery insertion. CAUTION: battery may be
damaged if device is operating in LDO mode with battery connected.
The internal power FET provides up to 1.2 amp of current at BATT pin in this mode. The LDO output is set to
4.1V. When operating at higher output currents, care must be taken not to exceed the package power dissipation
rating. See “Thermal Performance of WSON Package” section for more detail.
EN PIN
The Enable pin is used to enable/disable the charger, in both the charger mode and the LDO mode, see Figure 6
Figure 7. The enable pin is internally pulled HIGH to the CHG-IN pin. When the charger is disabled, it draws less
than 4 µA of current.
10
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VCHG-IN
CHG-IN
CHG-IN
VCHG-IN
0
VCHG-IN
VCHG-IN
EN
EN
0
0
4.1V
3.0V
Load < 50 mA
VBATT
VBATT
0
3.0V
0
Load > 50 mA
0
0
0
Time
Time
Figure 6. Power Up Timing Diagram in Charger Mode (1.39V < Ts < 2.427V)
VCHG-IN
CHG-IN
CHG-IN
VCHG-IN
0
VCHG-IN
0
EN
EN
VCHG-IN
0
4.1V
4.1V
VBATT
VBATT
0
0
0
0
0
Time
Time
Figure 7. Power Up Timing Diagram in LDO Mode (Ts ≥ 2.7V)
MODE PIN
The mode pin toggles the LP3947 between the AC adaptor mode and the USB mode. When CHG-IN is
connected to a USB port, this pin must be set low. When CHG-IN is connected to an AC adaptor, this pin must
be tied high to either the BATT pin or to the wall adaptor input. Caution: MODE pin should never be tied to CHGIN pin directly, as it will turn on an internal diode.
5.6 HR SAFETY TIMER IN CHARGER MODE
The LP3947 has a built-in 5.6 hr back up safety timer to prevent over-charging a Li Ion battery. The 5.6 hr timer
starts counting when the charger enters the constant current mode. It will turn the charger off when the 5.6 hr
timer is up while the charger is still in constant current mode. In this case, both LEDs will turn on, indicating a
fault condition.
When the battery temperature is outside the specified temperature range, the 5.6 hr safety timer will reset upon
recovery of the battery temperature.
I2C INTERFACE
I2C interface is used in the LP3947 to program various parameters as shown in Table 5. The LP3947 operates
on default settings following power up. Once programmed, the LP3947 retains the register data as long as the
battery voltage is above 2.85V.
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Table 5. LP3947 Serial Port Communication address code 7h’47
LP3947 Control and Data Codes (1)
(1)
Addrs
Register
8′h00
7
6
5
4
3
2
1
0
Charger
Register -1
Batt Voltage
(0) = 4.1V
1 = 4.2V
AC Adaptor
Charge
Current
Code 3 (1)
AC Adaptor
Charge Current
Code 2 (0)
AC Adaptor
Charge Current
Code 1 (0)
AC Adaptor
Charge Current
Code 0 (0)
8′h01
Charger
Register -2
EOC
(Green LED)
R/O
Charging
(Red LED)
R/O
EOC
SEL-1
(0)
EOC
SEL-0
(1)
8′h02
Charger
Register -3
USB
Charge
Current
Code 3 (1)
USB
Charge Current
Code 2 (0)
USB
Charge Current
Code 1 (0)
USB
Charge Current
Code 0 (0)
Numbers in parentheses indicate default setting. “0” bit is set to low state, and “1” bit is set to high state. R/O –Read Only, All other bits
are Read and Write.
Table 6. Charger Current and EOC Current Programming Code
Data Code
Charger Current
Selection Code ISET (mA)
4h′00
100
4h′01
150
0.1C
4h′02
200
0.15C
4h′03
250
0.2C
4h′04
300
4h′05
350
4h′06
400
4h′07
450
4h′08
500
4h′09
550
4h′0A
600
4h′0B
650
4h′0C
700
4h′0D
750
ack from slave
start
msb
ID
lsb
End of Charge Current
Selection Code
ack from slave
w ack msb ADDRESS lsb ack
ack from slave
lsb
ack
address h´00 data
ack
msb
DATA
stop
scl
sda
start
id = h´47
w ack
addr = h´00
ack
w = write (sda = “0”)
r = read (sda = “1”)
ack = acknowledge (sda pulled low by either master or slave)
Nack = No Acknowledge
rs = repeated start
Figure 8. LP3947 (Slave) Register Write
12
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ack from slave
start
msb
ID
lsb
ack from slave
w ack msb ADDRESS lsb ack
repeated start
rs
msb
ID
ack from slave
lsb
data from slave Nack from master
r ack
msb
DATA
lsb NA stop
r ack
address h´00 data Nack stop
scl
sda
start
id = h´47
w ack
addr = h´00
ack
rs
id = h´47
w = write (sda = “0”)
r = read (sda = “1”)
ack = acknowledge (sda pulled low by either master or slave)
Nack = No Acknowledge
rs = repeated start
Figure 9. LP3947 (Slave) Register Read
THERMAL PERFORMANCE OF WSON PACKAGE
The LP3947 is a monolithic device with an integrated pass transistor. To enhance the power dissipation
performance, the Leadless Lead frame Package, or WSON, is used. The WSON package is designed for
improved thermal performance because of the exposed die attach pad at the bottom center of the package. It
brings advantage to thermal performance by creating a very direct path for thermal dissipation. Compared to the
traditional leaded packages where the die attach pad is embedded inside the mold compound, the WSON
reduces a layer of thermal path.
The thermal advantage of the WSON package is fully realized only when the exposed die attach pad is soldered
down to a thermal land on the PCB board and thermal vias are planted underneath the thermal land. Based on a
WSON thermal measurement, junction to ambient thermal resistance (θJA) can be improved by as much as two
times if a WSON is soldered on the board with thermal land and thermal vias than if not.
An example of how to calculate for WSON thermal performance is shown below:
TJA =
TJ - TA
PD
(2)
By substituting 37°C/W for θJA, 125°C for TJ and 70°C for TA, the maximum power dissipation allowed from the
chip is 1.48W. If VCHG-IN is at 5.0V and a 3.0V battery is being charged, then 740 mA of ICHG can safely charge
the battery. More power can be dissipated at ambient temperatures below 70°C. Less power can be dissipated at
ambient temperatures above 70°C. The maximum power dissipation for operation can be increased by 27 mW
for each degree below 70°C, and it must be de-rated by 27 mW for each degree above 70°C.
LAYOUT CONSIDERATION
The LP3947 has an exposed die attach pad located at the bottom center of the WSON package. It is imperative
to create a thermal land on the PCB board when designing a PCB layout for the WSON package. The thermal
land helps to conduct heat away from the die, and the land should be the same dimension as the exposed pad
on the bottom of the WSON (1:1 ratio). In addition, thermal vias should be added inside the thermal land to
conduct more heat away from the surface of the PCB to the ground plane. Typical pitch and outer diameter for
these thermal vias are 1.27 mm and 0.33 mm respectively. Typical copper via barrel plating is 1oz although
thicker copper may be used to improve thermal performance. The LP3947 bottom pad is connected to ground.
Therefore, the thermal land and vias on the PCB board need to be connected to ground.
For more information on board layout techniques, refer to Application Note 1187 (SNOA401) “Leadless
Leadframe Package (LLP).” The application note also discusses package handling, solder stencil, and assembly.
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LP3947
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REVISION HISTORY
Changes from Revision A (April 2013) to Revision B
•
14
Page
Changed layout of National Data Sheet to TI format .......................................................................................................... 13
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PACKAGE OPTION ADDENDUM
www.ti.com
7-Oct-2013
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
Lead/Ball Finish
(2)
MSL Peak Temp
Op Temp (°C)
Device Marking
(3)
(4/5)
LP3947ISD-09/NOPB
ACTIVE
WSON
NHL
14
1000
Green (RoHS
& no Sb/Br)
CU SN
Level-1-260C-UNLIM
-40 to 85
L00061B
LP3947ISD-51/NOPB
ACTIVE
WSON
NHL
14
1000
Green (RoHS
& no Sb/Br)
CU SN
Level-1-260C-UNLIM
-40 to 85
L00062B
LP3947ISDX-51/NOPB
ACTIVE
WSON
NHL
14
4500
Green (RoHS
& no Sb/Br)
CU SN
Level-1-260C-UNLIM
-40 to 85
L00062B
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability
information and additional product content details.
TBD: The Pb-Free/Green conversion plan has not been defined.
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that
lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between
the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above.
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight
in homogeneous material)
(3)
MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.
(4)
There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device.
(5)
Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation
of the previous line and the two combined represent the entire Device Marking for that device.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information
provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and
continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals.
TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.
Addendum-Page 1
Samples
PACKAGE OPTION ADDENDUM
www.ti.com
7-Oct-2013
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.
Addendum-Page 2
PACKAGE MATERIALS INFORMATION
www.ti.com
11-Oct-2013
TAPE AND REEL INFORMATION
*All dimensions are nominal
Device
Package Package Pins
Type Drawing
SPQ
Reel
Reel
A0
Diameter Width (mm)
(mm) W1 (mm)
B0
(mm)
K0
(mm)
P1
(mm)
W
Pin1
(mm) Quadrant
LP3947ISD-09/NOPB
WSON
NHL
14
1000
178.0
12.4
4.3
4.3
1.3
8.0
12.0
Q1
LP3947ISD-51/NOPB
WSON
NHL
14
1000
178.0
12.4
4.3
4.3
1.3
8.0
12.0
Q1
LP3947ISDX-51/NOPB
WSON
NHL
14
4500
330.0
12.4
4.3
4.3
1.3
8.0
12.0
Q1
Pack Materials-Page 1
PACKAGE MATERIALS INFORMATION
www.ti.com
11-Oct-2013
*All dimensions are nominal
Device
Package Type
Package Drawing
Pins
SPQ
Length (mm)
Width (mm)
Height (mm)
LP3947ISD-09/NOPB
WSON
NHL
14
1000
210.0
185.0
35.0
LP3947ISD-51/NOPB
WSON
NHL
14
1000
210.0
185.0
35.0
LP3947ISDX-51/NOPB
WSON
NHL
14
4500
367.0
367.0
35.0
Pack Materials-Page 2
MECHANICAL DATA
NHL0014B
SDA14B (Rev A)
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