intersil ISL97656 DATA SHEET

®

ISL97656

Data Sheet April 23, 2009

Integrated 4A Switch PWM Step-Up
Regulator

The ISL97656 is a high frequency, high efficiency step-up
voltage regulator operated at constant frequency PWM
mode. With an internal 4.0A, 120mΩ MOSFET, it can deliver
up to 2A output current at over 90% efficiency. The
selectable 640kHz and 1.2MHz allows smaller inductors and
faster transient response. An external compensation pin
gives the user greater flexibility in setting frequency
compensation allowing the use of low ESR Ceramic output
capacitors.

When shut down, it draws <1µA of current and can operate
down to 2.3V input supply. These features along with

1.2MHz switching frequency makes it an ideal device for
portable equipment and TFT-LCD displays.

The ISL97656 is available in a 10 Ld TDFN package with a
maximum height of 1.1mm. The device is specified for
operation over the full -40°C to +85°C temperature range.

FN6439.3

Features

• >90% Efficiency

• 4.0A, 120mΩ Power MOSFET

• 2.3V to 6.0V Input

• Up to 24V Output

• 640kHz/1.2MHz Switching Frequency Selection

• Adjustable Soft-Start

• Internal Thermal Protection

• 0.8mm Max Height 10 Ld TDFN Package

• Pb-Free (RoHS Compliant)

• Halogen Free

Applications

• TFT-L CD Di sp l ays

• DSL Modems

Pinout

COMP

FB
EN

GND

GND

ISL97656

(10 LD TDFN)

TOP VIEW

1
2
3
4

5

• PCMCIA Cards

• Digital Cameras

• GSM/CDMA Phones

• Portable Equipment

SS

10

9

FREQ

8

IN

7

LX
LX

6

• Handheld Devices

Ordering Information

PART

NUMBER

(Note)

ISL97656IRTZ 656Z 10 Ld TDFN L10.3x3B
ISL97656IRTZ-T* 656Z 10 Ld TDFN L10.3x3B
ISL97656IRTZ-TK* 656Z 10 Ld TDFN L10.3x3B
*Please refer to TB347 for details on reel specifications.

NOTE: These Intersil Pb-free plastic packaged products employ
special Pb-free material sets, molding compounds/die attach
materials, and 100% matte tin plate plus anneal (e3 termination
finish, which is 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.

PART

MARKING

PACKAGE

(Pb-Free)

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.

Copyright Intersil Americas Inc. 2007, 2008, 2009. All Rights Reserved

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

ISL97656

Absolute Maximum Ratings (T

LX to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26V

IN to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.5V

COMP, FB, EN, SS, FREQ to GND. . . . . . . . . . .-0.3V to (IN +0.3V)

= +25°C) Thermal Information

A

Thermal Resistance (Typical) θ

10 Ld 3x3 TDFN Package (Notes 1, 2) 53 3

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

(°C/W) θJC (°C/W)

JA

Operating Junction Temperature . . . . . . . . . . . . . . . . . . . . . .+135°C

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

Pb-free reflow profile . . . . . . . . . . . . . . . . . . . . . . . . . .see link below

http://www.intersil.com/pbfree/Pb-FreeReflow.asp

CAUTION: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may adversely impact product reliability and
result in failures not covered by warranty.

NOTES:

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

1. θ

JA

2. For θ

IMPORTANT NOTE: All parameters having Min/Max specifications are guaranteed. Typical values are for information purposes only. Unless otherwise noted, all tests
are at the specified temperature and are pulsed tests, therefore: T

Electrical Specifications V

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

JC

= TC = T

= 3V, V

IN

OUT

J

= 12V, I

A

= 0mA, FREQ = GND, TA = -40°C to +85°C, unless otherwise specified.

OUT

Parameters with MIN and/or MAX limits are 100% tested at +25°C, unless otherwise specified. Temperature
limits established by characterization and are not production tested.

PARAMETER DESCRIPTION CONDITIONS MIN TYP MAX UNIT

I

Q1

I

Q2

I

Q3

V

I

B-FB

FB

Quiescent Current - Shutdown EN = 0V 0.1 5 µA
Quiescent Current - Not Switching EN = IN, FB = 1.3V 0.7 mA
Quiescent Current - Switching EN = IN, FB = 1.0V 3 5 mA
Feedback Voltage 1.22 1.24 1.26 V
Feedback Input Bias Current 0.01 0.5 µA

IN Input Voltage Range 2.3 6.0 V

D

- 640kHz Maximum Duty Cycle FREQ = 0V 85 92 %

MAX

D

- 1.2MHz Maximum Duty Cycle FREQ = IN 85 90 %

MAX

I

LIM

I

EN

r

DS(ON)

I

LX-LEAK

ΔV

/ΔVINLine Regulation 2.3V < VIN < 5.5V, V

OUT

ΔV

/ΔI

OUT

F

OSC1

F

OSC2

V

IL

V

IH

G

M

IN

-ON

Current Limit - Max Peak Input Current 3.8 4.0 5.1 A
Shutdown Input Bias Current EN = 0V 0.01 0.5 µA
Switch ON Resistance IN = 2.7V, ILX = 1A 0.12 Ω
Switch Leakage Current VSW = 27V 0.01 3 µA

= 12V 0.2 %

OUT

Load Regulation VIN = 3.3V , V

OUT

= 12V , IO = 30mA to 200mA 0.3 %

OUT

Switching Frequency Accuracy FREQ = 0V 500 640 740 kHz
Switching Frequency Accuracy FREQ = IN 1000 1220 1500 kHz
EN, FREQ Input Low Level 0.5 V
EN, FREQ Input High Level 1.5 V
Error Amp Tranconductance ΔI = 5µA 70 130 250 1µ/Ω
IN UVLO On Threshold 2.00 2.38 2.57 V

HYS IN UVLO hysteresis 50 mV

I

SS

Soft-Start Charge Current 2.5 4.5 7.5 µA

OTP Over-Temperature Protection 150 °C

2

FN6439.3

April 23, 2009

Block Diagram

ISL97656

EN SS

SHUTDOWN

AND START -UP

CONTROL

IN

REFERENCE
GENERATOR

COMPARATOR

COMP

FREQ

OSCILLATOR

CURRENT

SENSE

GM

AMPLIFIER

PWM LOGIC

CONTROLLER

Pin Descriptions

PIN NUMBER PIN NAME DESCRIPTION

FET

DRIVER

LX

GND

FB

1 COMP Compensation pin. Output of the internal error amplifier. Capacitor and resistor from COMP pin to ground.
2 FB Voltage feedback pin. Internal reference is 1.24V nominal. Connect a resistor divider from V

V

= 1.24V (1 + R1/R2). See “Typical Application Circuit”.

OUT

3 EN Shutdown control pin. Pull EN low to turn off the device.
4, 5 GND Analog and power ground.
6, 7 LX Power switch pin. Connected to the drain of the internal power MOSFET.

8 IN A nalog power supply input pin.

9 FREQ Frequency select pin. When FREQ is set low, switching frequency is set to 620kHz. When connected to

high or IN, switching frequency is set to 1.25MHz.

10 SS Soft-start control pin. Connect a capacitor to control the converter start-up.

Typical Application Circuit

3.9kΩ
C

4.7nF

1

2

3

4

5

COMP

FB

EN

GND

GND

R

3

5

1

86.6kΩR
R

10kΩ

2

SS

FREQ

LX

LX

10

9

IN

8

7

6

C

3

27nF

C

4

0.1µF

+

C

1

22µF

10µH

D

1

2.3V TO 6.0V

C

+

2

22µF

12V

OUT

.

3

FN6439.3

April 23, 2009