General Description

The MAX8570 family of LCD step-up converters uses

an internal n-channel switch and an internal p-channel

output isolation switch. These converters operate from

a 2.7V to 5.5V supply voltage and deliver up to 28V at

the output.

A unique control scheme provides the highest efficien-

cy over a wide range of load conditions. The internal

MOSFET switch reduces external component count and

a high switching frequency (up to 800kHz) allows for

tiny surface-mount components. Three current-limit

options are available. The MAX8570 and MAX8572 use

a 110mA current limit to reduce ripple and component

size in low-current applications. For high-power require-

ments, the MAX8574 and MAX8575 use a 500mA cur-

rent limit and supply up to 20mA at 20V. The MAX8571

and MAX8573 use a 250mA current limit for a compro-

mise between ripple and power. Built-in safety features

protect the internal switch and down-stream compo-

nents from fault conditions.

Additional features include a low quiescent current and

a True Shutdown

™ mode to save power. The MAX8570/

MAX8571/MAX8574 allow the user to set the output

voltage between 3V and 28V, and the MAX8572/

MAX8573/MAX8575 have a preset 15V output. These

step-up converters are ideal for small LCD panels with

low current requirements, but can also be used in other

applications. The MAX8571 evaluation kit is available to

help reduce design time.

Applications

LCD Bias Generators

Polymer LEDs (OLED)

Cellular or Cordless Phones

Palmtop Computers

Personal Digital Assistants (PDAs)

Organizers

Handy Terminals

Features

o 15V or Adjustable Output Voltage Up to 28V

o Safety Features Protect Against Output Faults

o 20mA at 20V from a Single Li+ Battery

o True Shutdown

o 87% Efficiency

o Up to 800kHz Switching Frequency

o Small, 6-Pin SOT23 and µDFN (MAX8570 Only)

Packages

High-Efficiency LCD Boost

with True Shutdown

________________________________________________________________

Maxim Integrated Products

1

Ordering Information

19-3329; Rev 3; 3/10

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,

or visit Maxim’s website at www.maxim-ic.com

EVALUATION

KIT

AVAILABLE

PART

TEMP RANGE

PIN-

PACKAGE

TOP

MARK

MAX8570ELT+T

-40

°C to +85°C

6L µDFN

ACW

MAX8570EUT+T

-40

°C to +85°C

6 SOT23

ABTJ

MAX8571EUT+T

-40

°C to +85°C

6 SOT23

ABTK

MAX8572EUT+T

-40

°C to +85°C

6 SOT23

ABTL

MAX8573EUT+T

-40

°C to +85°C

6 SOT23

ABTM

MAX8574EUT+T

-40

°C to +85°C

6 SOT23

ABTN

MAX8575EUT+T

-40

°C to +85°C

6 SOT23

ABTO

GND

LX

1

+

5SW

FB

MAX8570

MAX8571

MAX8574

SOT23

TOP VIEW

2

34

SHDN

Pin Configurations

PART

CURRENT LIMIT

OUTPUT VOLTAGE

MAX8570

110mA

Adjustable

MAX8571

250mA

Adjustable

MAX8572

110mA

15V

MAX8573

250mA

15V

MAX8574

500mA

Adjustable

MAX8575

500mA

15V

Selector Guide

True Shutdown is a trademark of Maxim Integrated Products, Inc.

MAX8572

MAX8573

MAX8575

SW

LX

OUT

GND

ON

OFF

SHDN

Typical Operating Circuit

+

Denotes a lead(Pb)-free RoHS-compliant package.

T = Tape and reel.

Pin Configurations continued at end of data sheet.