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Rainbow Electronics MAX1759 User Manual

Max1759 buck/boost regulating charge pump in µmax, General description, Applications

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General Description

The MAX1759 is a buck/boost regulating charge pump
that generates a regulated output voltage from a single
lithium-ion (Li+) cell, or two or three NiMH or alkaline
cells for small hand-held portable equipment. The
MAX1759 operates over a wide +1.6V to +5.5V input
voltage range and generates a fixed 3.3V or adjustable
(2.5V to 5.5V) output (Dual Mode

™)

. Maxim’s unique

charge-pump architecture allows the input voltage to be
higher or lower than the regulated output voltage.
Despite its high 1.5MHz operating frequency, the
MAX1759 maintains low 50µA quiescent supply current.

Designed to be an extremely compact buck/boost con-
verter, this device requires only three small ceramic
capacitors to build a complete DC-DC converter capa-
ble of generating a guaranteed 100mA (min) output
current from a +2.5V input. For added flexibility, the
MAX1759 also includes an open-drain power-OK
(POK) output that signals when the output voltage is in
regulation.

The MAX1759 is available in a space-saving 10-pin
µMAX package that is 1.09mm high and half the size of
an 8-pin SO.

Applications

Li+ Battery-Powered Applications

Miniature Equipment

Backup Battery Boost Converters

Translators

Features

Regulated Output Voltage (Fixed 3.3V or

Adjustable 2.5V to 5.5V)

100mA Guaranteed Output Current
+1.6V to +5.5V Input Voltage Range
Low 50µA Quiescent Supply Current
1µA Shutdown Mode
Load Disconnected from Input in Shutdown
High 1.5MHz Operating Frequency
Uses Small Ceramic Capacitors
Short-Circuit Protection and Thermal Shutdown
Small 10-Pin µMAX Package

MAX1759

Buck/Boost Regulating

Charge Pump in µMAX

________________________________________________________________ Maxim Integrated Products

1

1

2

3

4

5

10

9

8

7

6

FB

OUT

CXP

CXN

IN

IN

SHDN

POK

MAX1759

µMAX

TOP VIEW

PGND

GND

C

X

IN

+1.6V TO +5.5V

OUT

3.3V AT 100mA

C

IN

ON

OFF

C

OUT

POWER OK

OUT

POK

IN

CXN

CXP

PGND

GND

FB

SHDN

MAX1759

Typical Operating Circuit

19-1600; Rev 1; 6/00

PART

MAX1759EUB

-40°C to +85°C

TEMP. RANGE

PIN-PACKAGE

10 µMAX

Pin Configuration

Ordering Information

Dual Mode 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.