General Description

The MAX1748/MAX8726 triple-output DC-DC converters

in a low-profile TSSOP package provide the regulated

voltages required by active-matrix, thin-film transistor

(TFT) liquid-crystal displays (LCDs). One high-power

DC-DC converter and two low-power charge pumps

convert the +3.3V to +5V input supply voltage into three

independent output voltages.

The primary 1MHz DC-DC converter generates a boost-

inductors and ceramic capacitors. The low-power

BiCMOS control circuitry and the low on-resistance

(0.35

Ω) of the integrated power MOSFET allows effi-

ciency up to 93%.

The dual charge pumps independently regulate one

These low-power outputs use external diode and

capacitor stages (as many stages as required) to regu-

late output voltages up to +40V and down to -40V. A

proprietary regulation algorithm minimizes output rip-

ple, as well as capacitor sizes for both charge pumps.

For both the MAX1748 and MAX8726, the supply

The MAX1748 soft-starts each supply as soon as the

previous supply finishes. The MAX8726 adds a delay

The MAX1748/MAX8726 are available in the ultra-thin

TSSOP package (1.1mm max height).

Applications

TFT Active-Matrix LCD Displays

Passive-Matrix LCD Displays

PDAs

Digital Still Cameras

Camcorders

Features

♦ Three Integrated DC-DC Converters

♦ 1MHz Current-Mode PWM Boost Regulator

Up to +13V Main High-Power Output

±1% Accuracy

High Efficiency (93%)

♦ Dual Charge-Pump Outputs

Up to +40V Positive Charge-Pump Output

Down to -40V Negative Charge-Pump Output

♦ Internal Supply Sequencing

♦ Internal Power MOSFETs

♦ +2.7V to +5.5V Input Supply

♦ 0.1µA Shutdown Current

♦ 0.6mA Quiescent Current

♦ Internal Soft-Start

♦ Power-Ready Output

♦ Ultra-Small External Components

♦ Thin TSSOP Package (1.1mm max)

Triple-Output TFT-LCD

DC-DC Converters

________________________________________________________________ Maxim Integrated Products

1

16

15

14

13

12

11

10

9

1

2

3

4

5

6

7

8

RDY

TGND

LX

PGND

SUPP

DRVP

SUPN

DRVN

SHDN

TOP VIEW

MAX1748

MAX8726

TSSOP

FB

INTG

REF

IN

GND

FBP

FBN

Pin Configuration

19-3430; Rev 0; 10/04

For free samples and the latest literature, visit www.maxim-ic.com or phone 1-800-998-8800.

For small orders, phone 1-800-835-8769.

EVALUATION

KIT

AVAILABLE

Ordering Information

Typical Operating Circuit appears at end of data sheet.

PART

TEMP RANGE

PIN-PACKAGE

MAX1748EUE

-40°C to +85°C

16 TSSOP

MAX8726EUE

-40°C to +85°C

16 TSSOP