intersil ISL97631 DATA SHEET

®

www.BDTIC.com/Intersil

ISL97631

Data Sheet December 21, 2005

White LED Boost Regulator With
Integrated Schottky Diode

The ISL97631 represents a high efficiency, constant
frequency PWM regulator with integrated boost diode and
FET. Designed for use in white LED driving applications, the
ISL97631 features efficiencies up to 85%. It operates at

1.35MHz switching frequency and operates from an input
voltage of between 2.7V and 5.5V. The maximum output
voltage of 27V enables the ISL97631 to drive up to 6 LEDs in
series. It is also possible to use the ISL97631 to drive LEDs
in series/parallel combination for applications requiring up to
15 LEDs.

Available in the 6 Ld TSOT package, the ISL97631 offers
high efficiency, constant frequency operation. It is specified
for operation over the -40°C to +85°C ambient temperature
range.

Pinout

ISL97631

(6 LD TSOT)

TOP VIEW

VOUT

1

6

VIN

FN7370.1

Features

• Up to 6 LEDs in series

• 27V maximum output

• 2.7V to 5.5V input

• Up to 85% efficient

• 1.35MHz constant frequency

• Enable/PWM dimming control

• Pb-free plus anneal available (RoHS compliant)

Applications

• LED backlighting

• Cell phones

•PDAs

• Handheld games

• MP3 players

•GPS

• Other handheld devices

GND

LX

2

3

5FB

ENAB

4

Ordering Information

PAR T

PAR T N UMBE R

ISL97631IHTZ-T7 (See Note) 631Z 3,000 7” 6 Ld TSOT (Pb-free) MDP0049

ISL97631IHTZ-T7A (See Note) 631Z 270 7” 6 Ld TSOT (Pb-free) MDP0049

NOTE: Intersil Pb-free plus anneal products employ special Pb-free material sets; molding compounds/die attach materials and 100% matte tin plate
termination finish, which are RoHS compliant and compatible 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-020.

MARKING PCS.

TAPE &

REEL

PACKAGE

(TAPE AND REEL) PKG. DWG. #

1

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.

Copyright Intersil Americas Inc. 2005. All Rights Reserved

ISL97631

www.BDTIC.com/Intersil

Absolute Maximum Ratings (T

Input Voltage (VIN) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to +6V

LX, Vout Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-0.3V to +27V

FB Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to +6V

ENAB Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to +6V

Operating Temperature . . . . . . . . . . . . . . . . . . . . . . .-40°C to +85°C

= 25°C) Thermal Information

A

Thermal Resistance (Typical, Note 1) θJA (°C/W)

6 Ld TSOT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190

Maximum Junction Temperature (Plastic Package . . . . . . . . . 150°C

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

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

(TSOT - Lead Tips Only)

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.

IMPORTANT NOTE: All parameters having Min/Max specifications are guaranteed over the specified temperature range. All parameters are based on pulsed tests,
therefore: T

= TC = T

J

A

NOTE:

1. θ

is measured with the component mounted on a high effective thermal conductivity test board in free air. See Tech Brief TB379 for details.

JA

Electrical Specifications V

= 3V, V

IN

= 3V, TA = -40°C to 85°C unless otherwise specified.

ENAB

PARAMETER DESCRIPTION CONDITION MIN TYP MAX UNIT

V

IN-MIN

V

IN-MAX

V

I

FB

I

FB

IN

Minimum Operating Voltage V

Maximum Operating Voltage V

Feedback Voltage 80 100 120 mV

FB Pin Bias Current 100 nA

Supply Current ENAB = 3V, output not switching 0.6 1.0 mA

OUT

OUT

= 16V, I

= 25V, I

= 20mA 2.7 V

LED

= 20mA 5.5 V

LED

ENAB = 0V 1 µA

F

D

OSC

MAX

Switching Frequency 0.8 1.35 1.8 MHz

Maximum Duty Cycle TA = 25°C 85 90 %

82 90 %

I

LIM

Switch Current Limit TA = 25°C 280 350 mA

250 350 mA

r

DS(ON)

I

LEAK(LX)

I

LEAK(VOUT)

V

DIODE

V

ENAB-HI

V

ENAB-LO

I

ENAB

/∆V

∆I

LED

Eff Efficiency I

Switch On Resistance ILX = 100mA 750 mΩ

Switch Leakage Current VLX = 27V, Vout = 27V 0.01 1 µA

Diode Leakage Current V

LX-V

Diode Forward Voltage I

OUT

= 27V 0.01 1 µA

OUT

= 100mA, TA = 25°C 0.75 0.9 V

DIODE

ENAB Voltage High 2.5 V

ENAB Voltage Low 0.6 V

ENAB Pin Bias Current 1µA

Line Regulation VIN = 2.7V to 5V 0.2 %/V

IN

= 20mA, 3 LEDs 85 %

LED

2

FN7370.1

December 21, 2005

Typical Application

www.BDTIC.com/Intersil

L1

22µH

V

IN

2.7V~5.5V

C1

1µF

OFF/ON

V

IN

ISL97631

ENAB

V

OUT

GND

LX

FB

R

4.75Ω

FIGURE 1. TYPICAL APPLICATION CIRCUIT FIGURE 2. EFFICIENCY vs LED CURRENT (VIN = 4V)

Typical Performance Curves

SET

LEDs

C2

0.22µF

ISL97631

90

22µH, V

85

80

75

70

65

EFFICIENCY (%)

60

55

50

0 5 10 15 20 25 30

IN

= 4V

I

LED

(mA)

700
600
500
400
300

Iq (µA)

200
100

0

024

VIN (V)

6

FIGURE 3. QUIESCENT CURRENT vs VIN (ENAB = hi)

18.33

18.32

18.31

18.30

18.29

18.28

(mA)

O

I

18.27

18.26

18.25

18.24

18.23

2.5 3.5 4.5 5.5
(V)

V

IN

FIGURE 5. LINE REGULATION FIGURE 6. SWITCHING FREQUENCY vs TEMPERATURE

18.244

18.242

18.240

18.238

18.236

(mA)

O

I

18.234

18.232

18.230

18.228
0 5 10 15 20

(V)

V

OUT

FIGURE 4. LOAD REGULATION (V

1.37

1.36

1.35

1.34

1.33

1.32

1.31

1.30

FREQUENCY (MHz)

1.29

1.28

1.27

-60 -40 -20 0 20 40 60 80 100
TEMPERATURE (°C)

IN

= 4V)

3

FN7370.1

December 21, 2005