intersil ISL6257 DATA SHEET

ISL6257

Data Sheet January 17, 2007

Highly Integrated Narrow VDC Battery Charge r for Notebook Computers

The ISL6257 is a highly integrated battery charger controller for Li-Ion/Li-Ion polymer batteries. ISL6257 is designed for Narrow VDC applications where the system power source is either the battery pack or the regulated output of the charger. This makes the max voltage to the system equal to the max battery voltage instead of the max adapter voltage. Operating at lower system voltage can improve overall efficiency. High efficiency is achieved in the charger with a synchronous buck topology . The low -side MOSFET emul ates a diode at light loads to improve the light load efficiency and prevent system bus boosting.

The constant output voltage can be selected for 2, 3 and 4 series Li-Ion cells with ±0.5% accuracy over temperature. It can also be programmed between 4.2V + 5% per cell and

4.2V - 5% per cell to optimize battery capacity. When supplying the load and battery charger simultaneously, the input current limit for the AC adapter is programmable to within ±3% accuracy to avoid overloading the AC adapter and to allow the system to make efficient use of available adapter power for charging. It also has a wide range of programmable charging current. The ISL6257 automatically transitions from regulating current mode to regulating voltage mode.

FN9288.2

Features

• ±0.5% Charge Voltage Accuracy (-10°C to +100°C)

• ±3% Accurate Input Current Limit

• ±3% Accurate Battery Charge Current Limit

• ±25% Accurate Battery Trickle Charge Current Limit

• Programmable Charge Current Limit, Adapter Current Limit and Charge Voltage

• Fixed 300kHz PWM Synchronous Buck Controller with Diode Emulation at Light Load

• AC Adapter Present Indicator

• Fast Input Current Limit Response

• Input Voltage Range 7V to 25V

• Support 2, 3 and 4 Cells Battery Pack

• Up to 17.64V Battery-Voltage Set Point

• Control Adapter Power Source Select MOSFET

• Thermal Shutdown

• Aircraft Power Capable

• DC Adapter Present Indicator

• Battery Discharge MOSFET Control

• Less than 10µA Battery Leakage Current

• Support Pulse Charging

• Charge any Battery Chemistry: Li-Ion, NiCd, NiMH, etc.

• Pb-Free Plus Anneal Available (RoHS Compliant)

Ordering Information

PART

NUMBER

(Notes 1, 2)

ISL6257HRZ ISL6257HRZ -10 to +100 28 Ld 5x5 QFN L28.5×5 ISL6257HRZ-T ISL6257HRZ -10 to +100 28 Ld 5x5 QFN

NOTE: Intersil Pb-free plus anneal products employ special Pb-free material sets; molding compounds/die attach mat erials and 100% matt e tin plate termination finish, which are RoHS compliant and com patible with both SnPb and Pb-free soldering operations. Intersil Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-0 20.

PART

MARKING

TEMP

RANGE (°C)

PACKAGE

(Pb-free)

Tape & Reel

PKG.

DWG. #

L28.5×5

Applications

• Notebook, Desknote and Sub-notebook Computers

• Personal Digital Assistant

Pinout

ISL6257 (28 LD QFN)

TOP VIEW

DCSET

CELLS

ICOMP

VCOMP

VREF

CHLIM

ACSET

VDD

28 27 26 25 24 23 22

8 9 10 11 12 13 14

GND

VADJ

ACLIM

DCPRN

ACPRN

VDDP

CSON

BOOT

CSOP

CSIN

CSIP

SGATE

BGATE

PHASE

UGATE

DCIN

PGND

LGATE

CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.

1-888-INTERSIL or 1-888-468-3774

| Intersil (and design) is a registered trademark of Intersil Americas Inc.

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

ISL6257

Absolute Maximum Ratings Thermal Information

DCIN, CSIP, CSON to GND. . . . . . . . . . . . . . . . . . . . .-0.3V to +28V

CSIP-CSIN, CSOP-CSON. . . . . . . . . . . . . . . . . . . . . -0.3V to +0.3V

CSIP-SGATE, CSIP-BGATE . . . . . . . . . . . . . . . . . . . . .-0.3V to 16V

PHASE to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -7V to 30V

BOOT to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-0.3V to +35V

BOOT to VDDP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -2V to 28V

ACLIM, ACPRN, CHLIM, DCPRN, VDD to GND. . . . . . .-0.3V to 7V

BOOT-PHASE, VDDP-PGND . . . . . . . . . . . . . . . . . . . . . -0.3V to 7V

ACSET and DCSET to GND (Note 1) . . . . . . . -0.3V to VDD + 0.3V

FB, ICOMP, VCOMP to GND. . . . . . . . . . . . . . -0.3V to VDD + 0.3V

VREF, CELLS to GND . . . . . . . . . . . . . . . . . . . -0.3V to VDD + 0.3V

EN, VADJ, PGND to GND . . . . . . . . . . . . . . . . -0.3V to VDD + 0.3V

UGATE. . . . . . . . . . . . . . . . . . . . . . . . PHASE-0.3V to BOOT + 0.3V

LGATE. . . . . . . . . . . . . . . . . . . . . . . . . PGND-0.3V to VDDP + 0.3V

PGND to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to +0.3V

CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied.

NOTES:

1. ACSET and DCSET may be operated 1V below GND if the current through ACSET and DCSET is limited to less than 1mA.

is measured in free air with the component mounted on a high effective thermal conductivity test board with “direct attach” features. See T ech

2. θ

Brief TB379.

3. For θ

, the “case temp” location is the center of the exposed metal pad on the package underside.

Thermal Resistance θ

(°C/W) θJC (°C/W)

QFN Package (Notes 2, 3). . . . . . . . . . 39 9.5

QSOP Package (Note 2) . . . . . . . . . . . 80 NA

Junction Temperature Range. . . . . . . . . . . . . . . . . .-10°C to +150°C

Operating Temperature Range . . . . . . . . . . . . . . . .-10°C to +100°C

Storage Temperature. . . . . . . . . . . . . . . . . . . . . . . .-65°C to +150°C

Lead Temperature (soldering, 10s) . . . . . . . . . . . . . . . . . . . .+300°C

Electrical Specifications DCIN = CSIP = CSIN = 18V, CSOP = CSON = 12V, ACSET = DCSET = 1.5V, ACLIM = VREF,

VADJ=Floating, EN=VDD=5V, BOOT-PHASE=5.0V, GND=PGND=0V, C T

= -10°C to +100°C, TJ≤+125°C, unless otherwise noted.

PARAMETER TEST CONDITIONS MIN TYP MAX UNITS

SUPPLY AND BIAS REGULATOR

DCIN Input Voltage Range 725V DCIN Quiescent Current EN = VDD or GND, 7V ≤ DCIN ≤ 25V 1.4 3 mA Battery Leakage Current (Note 4) DCIN = 0, no load 3 10 µA VDD Output Voltage/Regulation 7V ≤ DCIN ≤ 25V, 0 ≤ I

≤ 30mA 4.925 5.075 5.225 V

VDD

VDD Undervoltage Lockout Trip Point VDD Rising 4.0 4.4 4.6 V

Hysteresis 150 250 400 mV

Reference Output Voltage VREF 0 ≤ I

≤ 300µA 2.365 2.39 2.415 V

VREF

FB Feedback Voltage 2.065 2.1 2.12 V Battery Charge Voltage Accuracy CSON = 16.8V, CELLS = VDD, VADJ = Float -0.5 0.5 %

CSON = 12.6V, CELLS = GND, VADJ = Float -0.5 0.5 % CSON = 8.4V, CELLS = Float, VADJ = Float -0.5 0.5 % CSON = 17.64V, CELLS = VDD, VADJ = VREF -0.5 0.5 % CSON = 13.23V, CELLS = GND, VADJ = VREF -0.5 0.5 % CSON = 8.82V, CELLS = Float, VADJ = VREF -0.5 0.5 % CSON = 15.96V, CELLS = VDD, VADJ = GND -0.5 0.5 % CSON = 11.97V, CELLS = GND, VADJ = GND -0.5 0.5 % CSON = 7.98V, CELLS = Float, VADJ = GND -0.5 0.5 %

TRIP POINTS

ACSET Threshold 1.24 1.26 1.28 V ACSET Input Bias Current Hysteresis 2.2 3.4 4.4 µA ACSET Input Bias Current ACSET ≥ 1.26V 2.2 3.4 4.4 µA

VDD

=1µF, I

VDD

=0mA,

FN9288.2

January 17, 2007

ISL6257

Electrical Specifications DCIN = CSIP = CSIN = 18V, CSOP = CSON = 12V, ACSET = DCSET = 1.5V, ACLIM = VREF,

VADJ=Floating, EN=VDD=5V, BOOT-PHASE=5.0V, GND=PGND=0V, C T

= -10°C to +100°C, TJ≤+125°C, unless otherwise noted. (Continued)

PARAMETER TEST CONDITIONS MIN TYP MAX UNITS

ACSET Input Bias Current ACSET < 1.26V -1 0 1 µA DCSET Threshold 1.24 1.26 1.28 V DCSET Input Bias Current Hysteresis 2.2 3.4 4.4 µA DCSET Input Bias Current DCSET ≥ 1.26V 2.2 3.4 4.4 µA DCSET Input Bias Current DCSET < 1.26V -1 0 1 µA

OSCILLATOR

Frequency 245 300 355 kHz PWM Ramp Voltage (peak-peak) CSIP = 18V 1.6 V

CSIP = 11V 1 V

SYNCHRONOUS BUCK REGULATOR

Maximum Duty Cycle 97 99 99.6 % UGATE Pull-Up Resistance BOOT - PHASE = 5V, 500mA source current 1.8 3.0 Ω UGATE Source Current BOOT - PHASE = 5V, BOOT-UGATE = 2.5V 1.0 A UGATE Pull-Down Resistance BOOT - PHASE = 5V, 500mA sink current 1.0 1.8 Ω UGATE Sink Current BOOT- PHASE = 5V, UGATE - PHASE = 2.5V 1.8 A LGATE Pull-Up Resistance VDDP - PGND = 5V, 500mA source current 1.8 3.0 Ω LGATE Source Current VDDP - PGND = 5V, VDDP - LGATE = 2.5V 1.0 A LGATE Pull-Down Resistance VDDP - PGND = 5V, 500mA sink current 1.0 1.8 Ω LGATE Sink Current VDDP - PGND = 5V, LGATE = 2.5V 1.8 A Dead Time Falling UGATE to rising LGATE or

CHARGING CURRENT SENSING AMPLIFIER

Input Common-Mode Range 0 18 V Input Offset Voltage Guaranteed by design -1.5 0 1.5 mV Input Bias Current at CSOP 5 < CSOP < 18V 0.25 2 µA Input Bias Current at CSON 5 < CSON < 18V 50 100 µA CHLIM Input Voltage Range 0 3.6 V CSOP to CSON Full-Scale Current Sense

Voltage

CHLIM Input Bias Current CHLIM = GND or 3.3V, DCIN = 0V -1 1 µA CHLIM Power-Down Mode Threshold

Voltage CHLIM Power-Down Mode Hysteresis

Voltage

ADAPTER CURRENT SENSING AMPLIFIER

Input Common-Mode Range 7 25 V Input Offset Voltage Guaranteed by design -1.5 1.5 mV Input Bias Current at CSIP and CSIN

Combined

falling LGATE to rising UGATE

CHLIM = 3.3V (4V<CSON<16.8V) 160 165 170 mV CHLIM = 2.0V (4V<CSON<16.8V) 97 100 103 mV CHLIM = 0.6V (4V<CSON<16.8V) 28.5 30.0 31.5 mV CHLIM = 0.2V (4V<CSON<16.8V) 7.5 10 12.5 mV

CHLIM rising 80 88 95 mV

CSIP = CSIN = 25V 100 130 µA

10 30 ns

15 25 40 mV

VDD

=1µF, I

VDD

=0mA,

FN9288.2

January 17, 2007

ISL6257

Electrical Specifications DCIN = CSIP = CSIN = 18V, CSOP = CSON = 12V, ACSET = DCSET = 1.5V, ACLIM = VREF,

VADJ=Floating, EN=VDD=5V, BOOT-PHASE=5.0V, GND=PGND=0V, C T

= -10°C to +100°C, TJ≤+125°C, unless otherwise noted. (Continued)

PARAMETER TEST CONDITIONS MIN TYP MAX UNITS

Input Bias Current at CSIN 0 < CSIN < DCIN, Guaranteed by design 0.10 1 µA

ADAPTER CURRENT LIMIT THRESHOLD

CSIP to CSIN Full-Scale Current Sense Voltage

ACLIM = VREF 97 100 103 mV ACLIM = Float 72 75 78 mV ACLIM = GND 47 50 53 mV

ACLIM Input Bias Current ACLIM= VREF 10 16 20 µA

ACLIM = GND -20 -16 -10 µA

VOLTAGE REGULATION ERROR AMPLIFIER

Error Amplifier Transconductance from VFB to VCOMP

CURRENT REGULATION ERROR AMPLIFIER

Charging Current Error Amplifier Transconductance

Adapter Current Error Amplifier Transconductance

from V

to ICOMP 50 µA/V

CA2

to ICOMP 50 µA/V

CA1

BATTERY CELL SELECTOR

CELLS Input Voltage for 4 Cell Select 4.3 V CELLS Input Voltage for 3 Cell Select 2V CELLS Input Voltage for 2 Cell Select 2.1 4.2 V

MOSFET DRIVER

BGATE Pull-Up Current CSIP - BGATE = 3V 10 30 45 mA BGATE Pull-Down Current CSIP - BGATE = 5V 2.7 4.0 5.0 mA CSIP - BGATE Voltage High 8 9.6 11 V CSIP - BGATE Voltage Low -50 0 50 mV DCIN - CSON Threshold for CSIP-BGATE

DCIN = 12V, CSON Rising -100 0 100 mV

Going High DCIN - CSON Threshold Hysteresis 250 300 400 mV SGATE Pull-Up Current CSIP - SGATE = 3V 7 12 15 mA SGATE Pull-Down Current CSIP - SGATE = 5V 50 160 370 µA CSIP - SGATE Voltage High 8 9 11 V CSIP - SGATE Voltage Low -50 0 50 mV CSIP - CSIN Threshold for CSIP - SGATE

2.5 8 13 mV

Going High CSIP - CSIN Threshold Hysteresis 1.3 5 8 mV

LOGIC INTERFACE

EN Input Voltage Range 0VDDV EN Threshold Voltage Rising 1.030 1.06 1.100 V

Falling 0.985 1.000 1.025 V

Hysteresis 30 60 90 mV EN Input Bias Current EN = 2.5V 1.8 2.0 2.2 µA ACPRN Sink Current ACPRN = 0.4V 3 8 11 mA ACPRN Leakage Current ACPRN = 5V -0.5 0.5 µA

VDD

=1µF, I

VDD

=0mA,

240 µA/V

FN9288.2

January 17, 2007

ISL6257

Electrical Specifications DCIN = CSIP = CSIN = 18V, CSOP = CSON = 12V, ACSET = DCSET = 1.5V, ACLIM = VREF,

VADJ=Floating, EN=VDD=5V, BOOT-PHASE=5.0V, GND=PGND=0V, C T

= -10°C to +100°C, TJ≤+125°C, unless otherwise noted. (Continued)

PARAMETER TEST CONDITIONS MIN TYP MAX UNITS

DCPRN Sink Current DCPRN = 0.4V 3 8 11 mA DCPRN Leakage Current DCPRN = 5V -0.5 0.5 µA CSON to GND resistance CSON = 12.6V 315 380 485 kΩ Thermal Shutdown Temperature 150 °C Thermal Shutdown Temperature Hysteresis 25 °C

NOTE:

4. This is the sum of currents in these pins (CSIP, CSIN, BGATE, BOOT, UGATE, PHASE, CSOP, CSON) all tied to 16.8V . No current in pins EN, ACSET, DCSET, VADJ, CELLS, ACLIM, CHLIM.

VDD

=1µF, I

VDD

=0mA,

Typical Operating Performance DCIN = 20V, 4S2P Li-Battery, T

0.6

0.3

0.0

-0.3

VDD LOAD REGULATION ACCURACY(%)

-0.6

(%)

ACCURACY

150 5 10 20 40

LOAD CURRENT (mA)

FIGURE 1. VDD LOAD REGULATION

9 8 7 6 5 4 3 2 1 0

10 20 30 40 50 60 70 80 90

CSIP-CSIN (mV)

100

VREF LOAD REGULATION ACCURACY(%)

EFFICIENCY (%)

= +25°C, unless otherwise noted.

0.10

0.08

0.06

0.04

0.02

0.00 0 100 200 300 400

LOAD CURRENT (μA)

FIGURE 2. VREF LOAD REGULATION

100

VCSON = 16.8V

VCSON = 12.6V

3 CELLS

4 CELLS

1.50 0.5 1.0 2.0 2.5 3.0 3.5 4.0

LOAD CURRENT (A)

VCSON = 8.4V

2 CELLS

FIGURE 3. ACCURACY vs AC ADAPTER CURRENT

FIGURE 4. SYSTEM EFFICIENCY vs CHARGE CURRENT

FN9288.2

January 17, 2007

ISL6257

Typical Operating Performance DCIN = 20V, 4S2P Li-Battery, T

DCIN

DCIN 10V/div

10V/div

ACSET

ACSET 1V/div

1V/div

DCSET

DCSET 1V/div

1V/div

DCPRN

DCPRN 5V/div

5V/div ACPRN

ACPRN 5V/div

5V/div

FIGURE 5. AC AND DC ADAPTER DETECTION

CSON

CSON 5V/div

5V/div

EN 5V/div

5V/div

INDUCTOR

INDUCTOR CURRENT

CURRENT 2A/div

2A/div

CHARGE

CHARGE CURRENT

CURRENT 2A/div

2A/div

= +25°C, unless otherwise noted. (Continued)

LOAD STEP: 0-4A CHARGE CURRENT: 3A

C ADAPTER CURRENT LIMIT: 5.15A

FIGURE 6. LOAD TRANSIENT RESPONSE

BATTERY

BATTERY REMOVAL

REMOVAL

VCOMP

ICOMP

BATTERY

BATTERY INSERTION

INSERTION

LOAD CURRENT 5A/div

DAPTER CURRENT 5A/div

CHARGE CURRENT 2A/div

BATTERY VOLTAGE 2V/div

INDUCTOR

INDUCTOR CURRENT

CURRENT 2A/div

2A/div

CSON

CSON 10V/div

10V/div

VCOMP

VCOMP 2V/div

2V/div

ICOMP

ICOMP 2V/div

2V/div

FIGURE 7. CHARGE ENABLE AND SHUTDOWN FIGURE 8. BATTERY INSERTION AND REMOVAL

CHLIM=0.2V

CHLIM=0.2V CSON=8V

CSON=8V

PHASE

PHASE 10V/div

10V/div

INDUCTOR

INDUCTOR CURRENT

CURRENT

CURRENT 1A/div

1A/div

UGATE

UGATE 5V/div

5V/div

FIGURE 9. SWITCHING WAVE FORMS IN DISCONTINUOUS

CONDUCTION MODE (DIODE EMULATION)

FIGURE 10. SWITCHING WAVE FORMS IN CONTINUOUS

CONDUCTION MODE

PHASE

PHASE 10V/div

10V/div

UGATE

UGATE 2V/div

2V/div

LGATE

LGATE 2V/div

2V/div

FN9288.2

January 17, 2007

ISL6257

Typical Operating Performance DCIN = 20V, 4S2P Li-Battery, T

SGATE-CSIP

SGATE-CSIP 2V/div

2V/div

ADAPTER REMOVAL

FIGURE 11. ADAPTER REMOVAL

2V/div

SYST EM BUS

SYST EM BUS VOLTAGE

VOLTAGE

VOLTAGE 10V/div

10V/div

BGATE-CSIP

BGATE-CSIP 2V/div

2V/div

INDUCTOR

INDUCTOR CURRENT

CURRENT

CURRENT 2A/div

2A/div

= +25°C, unless otherwise noted. (Continued)

ADAPTER INSERTION

FIGURE 12. ADAPTER INSERTION

BGATE-CSIP

BGATE-CSIP 2V/div

2V/div

SYSTEM BUS

SYSTEM BUS VOLTAGE

VOLTAGE

VOLTAGE 10V/div

10V/div

SGATE-CSIP

SGATE-CSIP 2V/div

2V/div

INDUCTOR

INDUCTOR CURRENT

CURRENT

CURRENT 2A/div

2A/div

FIGURE 13. ADAPTER INSERTION WITH A CHARGED

BATTERY

FIGURE 14. ADAPTER INSERTION WITH NO BATTERY AND A

2A SYSTEM LOAD

ISL6257 CHARGE CURVES

V ba ttery

BATTERY VOLTAG

0 50 100 150 200

TIM E (MINUTES)

FIGURE 15. BATTERY CHARGE VOLTAGE AND CURRENT

I batter

2.5

2.0

1.5

1.0

0.5

0.0

100%

95%

90%

85%

Efficiency

BATTERY CURREN

80%

75%

10Vin-8.4Vout 25Vin-8.4Vout 15Vin-12.6Vout 25Vin-12.6Vout 20Vin-16.8Vout 25Vin-16.8Vout

70%

024681012

Load Current (Amps)

FIGURE 16. EFFICIENCY VS LOAD CURRENT

Efficiency vs load current

FN9288.2

January 17, 2007

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