_______________General Description

The MAX774/MAX775/MAX776 inverting switching

regulators deliver high efficiency over three decades of

load current.

A unique current-limited, pulse-

frequency-modulated (PFM) control scheme provides

the benefits of pulse-width modulation (high efficiency

with heavy loads), while using less than 100µA of sup-

ply current (vs. 2mA to 10mA for PWM converters). The

result is high efficiency over a wide range of loads.

These ICs also use tiny external components; their high

switching frequency (up to 300kHz) allows for less than

5mm diameter surface-mount magnetics.

The MAX774/MAX775/MAX776 accept input voltages from

3V to 16.5V, and have preset output voltages of

-5V, -12V, and -15V, respectively. Or, the output voltage

can be user-adjusted with two resistors. Maximum

down voltage of the chosen external switch transistor.

These inverters use external P-channel MOSFET switch-

es, allowing them to power loads up to 5W. If less

power is required, use the MAX764/MAX765/MAX766

inverting switching regulators with on-board MOSFETs.

________________________Applications

LCD-Bias Generators

High-Efficiency DC-DC Converters

Battery-Powered Applications

Data Communicators

____________________________Features

o 85% Efficiency for 5mA to 1A Load Currents

o Up to 5W Output Power

o 100µA Max Supply Current

o 5µA Max Shutdown Current

o 3V to 16.5V Input Range

o -5V (MAX774), -12V (MAX775), -15V (MAX776),

or Adjustable Output Voltage

o Current-Limited PFM Control Scheme

o 300kHz Switching Frequency

______________Ordering Information

Ordering Information continued on last page.

* Contact factory for dice specifications.

-5V/-12V/-15V or Adjustable,

________________________________________________________________

Maxim Integrated Products

1

1

2

3

4

5

8

7

6

MAX774

MAX775

MAX776

DIP/SO

TOP VIEW

GND

EXT

CS

V+

OUT

FB

SHDN

REF

__________________Pin Configuration

MAX774

OUTPUT

-5V

REF

SHDN

GND

V+

CS

EXT

OUT

ON/OFF

INPUT

3V TO 16V

P

FB

__________Typical Operating Circuit

Call toll free 1-800-998-8800 for free samples or literature.

PART

TEMP. RANGE

PIN-PACKAGE

MAX774CPA

0°C to +70°C

8 Plastic DIP

MAX774CSA

0°C to +70°C

8 SO

MAX774C/D

0°C to +70°C

Dice*

MAX774EPA

-40°C to +85°C

8 Plastic DIP

MAX774ESA

-40°C to +85°C

8 SO

MAX774MJA

-55°C to +125°C

8 CERDIP

19-0191; Rev 1; 3/94

EVALUATION

KIT

AVAILABLE