LP3947
www.ti.com
SNVS298B – NOVEMBER 2004 – REVISED APRIL 2013
LP3947 USB/AC Adaptor, Single Cell Li-Ion Battery Charger IC
Check for Samples: LP3947
FEATURES
DESCRIPTION
•
•
•
•
•
•
•
•
•
•
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
•
•
•
•
•
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
•
•
•
•
•
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
www.ti.com
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
Submit Documentation Feedback
Copyright © 2004–2013, Texas Instruments Incorporated
Product Folder Links: LP3947
LP3947
www.ti.com
SNVS298B – NOVEMBER 2004 – REVISED APRIL 2013
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.
Submit Documentation Feedback
Copyright © 2004–2013, Texas Instruments Incorporated
Product Folder Links: LP3947
3
LP3947
SNVS298B – NOVEMBER 2004 – REVISED APRIL 2013
www.ti.com
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.
Submit Documentation Feedback
Copyright © 2004–2013, Texas Instruments Incorporated
Product Folder Links: LP3947
LP3947
www.ti.com
SNVS298B – NOVEMBER 2004 – REVISED APRIL 2013
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.
Submit Documentation Feedback
Copyright © 2004–2013, Texas Instruments Incorporated
Product Folder Links: LP3947
5
LP3947
SNVS298B – NOVEMBER 2004 – REVISED APRIL 2013
www.ti.com
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
Submit Documentation Feedback
Copyright © 2004–2013, Texas Instruments Incorporated
Product Folder Links: LP3947
LP3947
www.ti.com
SNVS298B – NOVEMBER 2004 – REVISED APRIL 2013
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
Submit Documentation Feedback
Copyright © 2004–2013, Texas Instruments Incorporated
Product Folder Links: LP3947
7
LP3947
SNVS298B – NOVEMBER 2004 – REVISED APRIL 2013
4.3V < VCHG-IN < 6.0V
and
VBATT < VCHG-IN
www.ti.com
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