General Description

The MAX1795/MAX1796/MAX1797 are high efficiency

step-up DC-DC converters intended for small portable

hand-held devices. These devices feature Maxim’s

True-Shutdown™ circuitry, which fully disconnects the

output from the input in shutdown, improves efficiency,

and eliminates costly external components. All three

devices also feature Maxim’s proprietary LX-damping

circuitry for reduced EMI in noise-sensitive applica-

tions. For additional in-system flexibility, a battery moni-

toring comparator (LBI/LBO) remains active even when

the DC-DC converter is in shutdown.

can be set from +2V to +5.5V. Startup is guaranteed

from +0.85V. The MAX1795/MAX1796/MAX1797 have a

preset, pin-selectable 5V or 3.3V output. The output

can also be adjusted to other voltages, using two exter-

nal resistors. The three devices differ only in their cur-

rent limits, allowing optimization of external components

for different loads: The MAX1795, MAX1796, and

MAX1797 have current limits of 0.25A, 0.5A, and 1A,

respectively. All devices are packaged in a compact 8-

pin µMAX package that is only 1.09mm tall and half the

size of an 8-pin SO.

________________________Applications

Portable Digital Audio Players

PDAs/Palmtops

Wireless Handsets

Portable Terminals

Features

o >95% Efficiency

o True-Shutdown Circuitry

Output Disconnects from Input in Shutdown

No External Schottky Diode Needed

o 25µA Quiescent Supply Current

o Low-Noise Antiringing Feature

o LBI/LBO Comparator Enabled in Shutdown

o 2µA Shutdown Current

o 8-Pin µMAX Package

Low Supply Current, Step-Up DC-DC Converters

with True-Shutdown

________________________________________________________________ Maxim Integrated Products

1

1

2

3

4

8

7

6

5

BATT

OUT

LX

GND

LBO

FB

LBI

MAX1795

MAX1796

MAX1797

µMAX

TOP VIEW

SHDN

Pin Configuration

GND

LBI

LBO

BATT

FB

LX

OUT

MAX1795

MAX1796

MAX1797

SHDN

OUT

IN

0.7V TO

5.5V

ON

OFF

Typical Operating Circuit

19-1798; Rev 0; 12/00

Ordering Information

PART

TEMP. RANGE

PIN-PACKAGE

MAX1795EUA

-40

°C to +85°C

8

µMAX

MAX1796EUA

-40

°C to +85°C

8

µMAX

MAX1797EUA

-40

°C to +85°C

8

µMAX

True-Shutdown is a trademark of Maxim Integrated Products.

For price, delivery, and to place orders, please contact Maxim Distribution at 1-888-629-4642,

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