General Description

The MAX1748 triple-output DC-DC converter in a low-

profile TSSOP package provides the regulated voltages

required by active matrix, thin-film transistor (TFT) liquid

crystal displays (LCDs). One high-power DC-DC con-

verter and two low-power charge pumps convert the

+3.3V to +5V input supply voltage into three independent

output voltages.

The primary high-power DC-DC converter generates a

lated within ±1%. The low-power BiCMOS control cir-

cuitry and the low on-resistance (0.35

Ω) of the

integrated power MOSFET allows efficiency up to 93%.

The 1MHz current-mode PWM architecture provides

fast transient response and allows the use of ultra-small

inductors and ceramic capacitors.

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.

The MAX1748 is available in the ultra-thin TSSOP pack-

age (1.1mm max height).

________________________Applications

TFT Active Matrix LCD Displays

Passive Matrix LCD Displays

PDAs

Digital Still Cameras

Camcorders

Features

o Three Integrated DC-DC Converters

o 1MHz Current-Mode PWM Boost Regulator

Up to +13V Main High-Power Output

±1% Accuracy

High Efficiency (93%)

o Dual Charge-Pump Outputs

Up to +40V Positive Charge-Pump Output

Down to -40V Negative Charge-Pump Output

o Internal Supply Sequencing

o Internal Power MOSFETs

o +2.7V to +5.5V Input Supply

o 0.1µA Shutdown Current

o 0.6mA Quiescent Current

o Internal Soft-Start

o Power-Ready Output

o Ultra-Small External Components

o Thin TSSOP Package (1.1mm max)

Triple-Output TFT LCD DC-DC Converter

________________________________________________________________ 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

TSSOP

FB

INTG

REF

IN

GND

FBP

FBN

Pin Configuration

19-1740; Rev 0; 6/00

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.

Ordering Information

Typical Operating Circuit appears at end of data sheet.

16 TSSOP

PIN-PACKAGE

TEMP. RANGE

-40°C to +85°C

MAX1748EUE

PART