LP3947ISD-09/NOPB - Texas Instruments

1 PF

ISEL

MODE

SCL

SDA

VTRS

VBSense

BATT

10 PF

Li-Ion

CHG

EOC

GND

CHG-IN

LP3947

System

Supply

Diff-Amp

USB Power Source

4.3V to 5.5V

LP3947

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SNVS298B –NOVEMBER 2004–REVISED APRIL 2013

LP3947 USB/AC Adaptor, Single Cell Li-Ion Battery Charger IC

Check for Samples: LP3947

1FEATURES DESCRIPTION

The LP3947 is a complete charge management

23• Supports USB Charging Scheme system that safely charges and maintains a Li-Ion

• Integrated Pass Transistor battery from either USB power source or AC adaptor.

• Near-Depleted Battery Preconditioning In USB mode, the LP3947 supports charging in low

power or high power mode. Alternatively, the LP3947

• Monitors Battery Temperature can take charge from AC adaptor. In both USB and

• Built-In 5.6 Hour Timer AC adaptor modes, charge current, battery regulation

• Under Voltage and Over Voltage Lockout voltage, and End of Charge (EOC) point can be

selected via I2C™ interface. The LP3947 can also

• Charge Status Indicators operate on default values that are pre-programmed in

• Charge Current Monitor Analog Output the factory. The battery temperature is monitored

• LDO Mode Operation can source 1 Amp continuously at the Ts pin to safeguard against

hazardous charging conditions. The charger also has

• Continuous Over Current/Temperature under-voltage and over-voltage protection as well as

Protection an internal 5.6 hr timer to protect the battery. The

pass transistor and charge current sensing resistor

APPLICATIONS are all integrated inside the LP3947.

• Cellular Phones The LP3947 operates in four modes: pre-qualification,

• PDAs constant current, constant voltage and maintenance

• Digital Cameras modes. There are two open drain outputs for status

indication. An internal amplifier readily converts the

• USB Powered Devices charge current into a voltage. Also, the charger can

• Programmable Current Sources 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

More Application Circuit can be found in APPLICATION NOTES.

1Please 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.

2I2C is a trademark of Philips Semiconductor Corporation.

3All other trademarks are the property of their respective owners.

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.

14 13 12 11 10 9 8

1 2 3 4 5 6 7

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

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 VTRegulated 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

Product Folder Links: LP3947

Charger

control

CHG-IN

SCL

SDA

Mode

RSENSE

Vref +

ISEL

CHG

BATT

Diff Amp

EOC

I2C and Digital

ON/OFF

Control

LED

Driver

Power

FET

Control LDO

Mode

UTLO

OTLO

LDO

Error

Amp

LP3947

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SNVS298B –NOVEMBER 2004–REVISED APRIL 2013

LP3947 FUNCTIONAL BLOCK DIAGRAM

ABSOLUTE MAXIMUM RATINGS (1) (2)

If Military/Aerospace specified devices are required, contact the Texas Instruments Semiconductor Sales Office/

Distributors for availability and specifications.

CHG-IN −0.3V to +6.5V

All pins except GND and CHG-IN (3) −0.3V to +6V

Junction Temperature 150°C

Storage Temperature −40°C to +150°C

Power Dissipation (4) 1.89W

ESD (5)

Human Body Model 2 kV

Machine Model 200V

(1) All voltages are with respect to the potential at the GND pin.

(2) 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.

(3) Caution must be taken to avoid raising pins EN and VT0.3V higher than VCHG-IN and raising pins ISEL, MODE, SCL and SDA 0.3V

higher than VBATT.

(4) The Absolute Maximum power dissipation depends on the ambient temperature and can be calculated using the formula

MM P = (TJ– TA)θJA,

where TJis the junction temperature, TAis 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.

(5) The human-body model is used. The human-body model is 100 pF discharged through 1.5 kΩ.

Product Folder Links: LP3947

LP3947

SNVS298B –NOVEMBER 2004–REVISED APRIL 2013

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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

Junction Temperature −40°C to +125°C

Operating Temperature −40°C to +85°C

Thermal Resistance θJA 37°C/W

Maximum Power Dissipation (4) 1.21W

(1) 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.

(2) All voltages are with respect to the potential at the GND pin.

(3) Caution must be taken to avoid raising pins EN and VT0.3V higher than VCHG-IN and raising pins ISEL, MODE, SCL and SDA 0.3V

higher than VBATT.

(4) 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.

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)

Limit

Symbol Parameter Conditions Typ Units

Min Max

VCC SUPPLY

VCHG-IN Input Voltage Range 4.5 6 V

VUSB 4.3 6

ICC Quiescent Current VCHG-IN ≤4V 2 20 µA

EOC = Low, adaptor connected, VBATT =50 150

4.1V

VOK-TSHD Adaptor OK Trip Point (CHG-IN) VCHG-IN –VBATT (Rising) 60 mV

VCHG-IN –VBATT (Falling) 50 mV

VUVLO-TSHD Under Voltage Lock-Out Trip Point VCHG-IN (Rising) 3.95 3.6 4.3 V

VCHG-IN (Falling) 3.75 3.4 4.1 V

VOVLO-TSHD Over Voltage Lock-Out Trip Point VCHG-IN (Rising) 5.9 V

VCHG-IN (Falling) 5.7

Thermal Shutdown Temperature (2) 160 °C

Thermal Shutdown Hysteresis 20

BATTERY CHARGER

ICHG Fast Charge Current Range ISEL = High, In USB Mode 100

ISEL = Low, In USB Mode 500 mA

In AC Adaptor Mode 100 750

Fast Charge Current Accuracy ICHARGE = 100 mA or 150 mA −20 +20 mA

ICHARGE ≥200 mA −10 +10 %

IPRE-CHG Pre-Charge Current VBATT = 2V 45 70 mA

(1) 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.

(2) Specified by design.

(3) LP3947 is not intended as a Li-Ion battery protection device, any battery used in this application should have an adequate internal

protection.

Product Folder Links: LP3947

LP3947

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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)

Limit

Symbol Parameter Conditions Typ Units

Min Max

IEOC End of Charge Current Accuracy 100 mA to 450 mA, 0.1C EOC Only (4) −10 +10 mA

500 mA to 750 mA, All EOC Points −20 +20 %

VBATT Battery Regulation Voltage (For 4.1V TJ= 0°C to +85°C 4.1 4.059 4.141

Cell) TJ=−40°C to +85°C 4.1 4.038 4.162 V

Battery Regulation Voltage (For 4.2V TJ= 0°C to +85°C 4.1 4.158 4.242

Cell) TJ=−40°C to +85°C 4.2 4.137 4.263

VCHG-Q Full Charge Qualification Threshold VBATT Rising, Transition from Pre-Charge 3.0 V

to Full Current

VBAT-RST Restart Threshold Voltage VBATT Falling, Transition from EOC, to Pre- 3.9 3.77 4.02

(For 4.1V Cell) Qualification State V

Restart Threshold Voltage VBATT Falling, Transition from EOC, to Pre- 4.00 3.86 4.12

(For 4.2V Cell) Qualification State

RSENSE Internal Current Sense Resistance (2) 120 mΩ

Internal Current Sense Resistor Load 1.2 A

Current

ICHGMON Diff-Amp Output ICHG = 50 mA 0.583

ICHG = 100 mA 0.663 V

ICHG = 750 mA 1.790

tOUT Charger Time Out TJ= 0°C to 85°C 5.625 4.78 6.42 Hrs

TJ=−40°C to +85°C 5.625 4.5 6.75

VOL Low Level Output Voltage EOC, CHG Pins each at 9 mA 100 mV

TEMPERATURE SENSE COMPARATORS

VUTLO Low Voltage Threshold Voltage at Ts Pin, Rising 2.427 V

Voltage at Ts Pin, Falling 2.369

VOTLO High Voltage Threshold Voltage at Ts Pin, Rising 1.470 V

Voltage at Ts Pin, Falling 1.390

VLDO LDO Mode Voltage Threshold Voltage at Ts Pin, % of VT97 %

VTVoltage Output 2.787 V

LDO MODE (Ts = HIGH)

VOUT Output Voltage Regulation ILOAD = 50 mA 4.10 V

ILOAD = 750 mA 4.06

LOGIC LEVELS

VIL Low Level Input Voltage EN, ISEL, MODE 0.4 V

VIH High Level Input Voltage EN, ISEL, MODE 2.0 V

IIL Input Current EN, ISEL = LOW −10 +10 µA

MODE = LOW −5 +5 µA

IIH Input Current EN, ISEL, MODE = HIGH −5 +5 µA

(4) 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.

Product Folder Links: LP3947

4.1V

3.9V

Prequalification to Fast

Charge transition

Battery

Voltage

Battery

Current

CC to CV transition

4.1V 0r 4.2V

Time

OFF ON

OFF

50 mA

GLED

RLED

End of Charge

Current

0.1C (Default)

Battery Voltage

Charge Current

LP3947

SNVS298B –NOVEMBER 2004–REVISED APRIL 2013

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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)

Limit

Symbol Parameter Conditions Typ Units

Min Max

VIL Low Level Input Voltage 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) 400 kHz

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

tSU Set-Up Time Repeated START (2) 0.6 µs

Condition

tDATA-HOLD 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 (2)

must be Suppressed by the Input Filter 50 ns

of both DATA & CLK Signals.

(1) 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.

(2) Specified by design.

(3) LP3947 is not intended as a Li-Ion battery protection device, any battery used in this application should have an adequate internal

protection.

Figure 2. Li-Ion Charging Profile

Product Folder Links: LP3947

1 PF

ISEL

Mode

SCL

SDA

VBSense

BATT

10 PF

Li-Ion

CHG

EOC

GND

CHG-IN

LP3947

Wall

Adaptor

System

Supply

USB

Port

P-Ch

MOSFET

Diff-Amp

10k

LP3947

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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 CHG-

IN 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.

Figure 3. LP3947 with External Switch

Product Folder Links: LP3947

Timer time out

Charger = Off

Timer resets

RLED = ON

GLED = ON

Disconnect

power at

CHG-IN pin to

restart charger

Maintenance Mode

Charger = Off

RLED = Off

GLED = On

1.39V<Ts<2.42V

Battery Temp

violation

Charger = Off

Timer resets

RLED = ON

GLED = ON

Set Fast Charge Current = I

Start 5.6 hr Timer

Timer =

5.6 hr?

EN pin =

low?

1.39V<Ts<2.42V

VBATT > = 4.1V*?

1.39V<Ts<2.42V

Constant Voltage Mode

VBATT = 4.1V *

Pre-Qualification

Charge Current = 50 mA

RLED = On

GLED = Off

1.39V<Ts<2.42V

LDO Mode

ICHG = 1.2A

VBATT = 4.1V*

LED's Off

4.3V < VCHG-IN < 6.0V

and

VBATT < VCHG-IN

1.39V < Ts < 2.42V

4.3V < VCHG-IN < 6V

Ts t2.7V VBATT > VCHG-IN

LED's Off

Charger Off

1.39V<Ts<2.42V

Timer =

5.6 hr?

EN pin =

low?

VBATT > 3.0V? N

IEOC < (0.1 x ICHG)*?

* Default Value. See "I2C Interface" section.

VBATT > 3.0V? NY

VBATT < 3.9V

EN pin =

High?

and

LP3947

SNVS298B –NOVEMBER 2004–REVISED APRIL 2013

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Figure 4. LP3947 Charger Flow Chart

Product Folder Links: LP3947

CHG-IN Batt

RSense

Diff-Amp

120 m:

0.583V

50 mA Charge Current 750 mA

1.74V

Diff-Amp

Output

ICHG = (VDIFF - 0.497)

1.655

LP3947

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SNVS298B –NOVEMBER 2004–REVISED APRIL 2013

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 ISEL Pin Functions

AC Adaptor Mode HIGH HIGH ISEL polarity is irrelevant. Default 500 mA charge current. Can be reprogrammed via

I2C.

HIGH LOW

USB Mode 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 mΩcurrent sense resistor. The differential amplifier

provides the analog representation of the charge current. Charge current can be calculated using the following

equation:

(1)

Where voltage at Diff Amp output (VDIFF) is in volt, and charge current (ICHG) is in amps.

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.

Product Folder Links: LP3947

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SNVS298B –NOVEMBER 2004–REVISED APRIL 2013

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Table 3. LED Indicator Summary

RED LED GREEN LED (EOC)

(CHG)

Charger Off OFF 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 RTand 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 RTis 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 10kΩfor the thermistor and a 4.1kΩfor Rsshould 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 Charger Off

0V ≤Ts ≤1.39V

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.

Product Folder Links: LP3947

00 TimeTime

4.1V

VCHG-IN

CHG-IN

VBATT

VCHG-IN

CHG-IN

VBATT

Load < 50 mA

Load > 50 mA

00 TimeTime

4.1V

3.0V

VCHG-IN

3.0V

CHG-IN

VBATT

VCHG-IN

CHG-IN

VBATT

LP3947

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SNVS298B –NOVEMBER 2004–REVISED APRIL 2013

Figure 6. Power Up Timing Diagram in Charger Mode (1.39V < Ts < 2.427V)

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 CHG-

IN 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.

Product Folder Links: LP3947

ack

address h´00 data

ack

addr = h´00

ackw

id = h´47

start

scl

sda

start msb ID lsb wack msb ADDRESS lsb ack msb DATA lsb ack

ack from slave ack from slave ack from slave

stop

LP3947

SNVS298B –NOVEMBER 2004–REVISED APRIL 2013

www.ti.com

Table 5. LP3947 Serial Port Communication address code 7h’47

LP3947 Control and Data Codes(1)

Addrs Register 7 6 5 4 3 2 1 0

8′h00 Charger Batt Voltage AC Adaptor AC Adaptor AC Adaptor AC Adaptor

1 = 4.2V Current Code 2 (0) Code 1 (0) Code 0 (0)

Code 3 (1)

8′h01 Charger EOC Charging EOC EOC

R/O R/O (0) (1)

8′h02 Charger USB USB USB USB

Current Code 2 (0) Code 1 (0) Code 0 (0)

Code 3 (1)

(1) 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

Charger Current End of Charge Current

Data Code Selection Code ISET (mA) Selection Code

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

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

Product Folder Links: LP3947

TJA = TJ - TA

Nack stop

address h´00 data

ackr

id = h´47

rsack

addr = h´00

ackw

id = h´47

start

scl

sda

start msb ID lsb w ack msb ADDRESS lsb ack rs msb ID lsb r ack msb lsb NA stopDATA

ack from slave repeated startack from slave ack from slave data from slave Nack from master

LP3947

www.ti.com

SNVS298B –NOVEMBER 2004–REVISED APRIL 2013

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:

(2)

By substituting 37°C/W for θJA, 125°C for TJand 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.

Product Folder Links: LP3947

LP3947

SNVS298B –NOVEMBER 2004–REVISED APRIL 2013

www.ti.com

REVISION HISTORY

Changes from Revision A (April 2013) to Revision B Page

• Changed layout of National Data Sheet to TI format .......................................................................................................... 13

Product Folder Links: LP3947

PACKAGE OPTION ADDENDUM

www.ti.com 8-Oct-2015

Addendum-Page 1

PACKAGING INFORMATION

Orderable Device Status

(1)

Package Type Package

Drawing Pins Package

Qty Eco Plan

(2)

Lead/Ball Finish

(6)

MSL Peak Temp

(3)

Op Temp (°C) Device Marking

(4/5)

Samples

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

(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.

(6) Lead/Ball Finish - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead/Ball Finish values may wrap to two lines if the finish

value exceeds the maximum column width.

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.

PACKAGE OPTION ADDENDUM

www.ti.com 8-Oct-2015

Addendum-Page 2

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.

TAPE AND REEL INFORMATION

*All dimensions are nominal

Device Package

Type Package

Drawing Pins SPQ Reel

Diameter

(mm)

Reel

Width

W1 (mm)

(mm) B0

(mm) K0

(mm) P1

(mm) W

(mm) Pin1

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

PACKAGE MATERIALS INFORMATION

www.ti.com 2-Sep-2015

Pack Materials-Page 1

*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

PACKAGE MATERIALS INFORMATION

www.ti.com 2-Sep-2015

Pack Materials-Page 2

MECHANICAL DATA

NHL0014B

www.ti.com

SDA14B (Rev A)

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