General Description

The MAX5014/MAX5015 integrate all the building

blocks necessary for implementing DC-DC fixed-fre-

quency isolated power supplies. These devices are

current-mode controllers with an integrated high-volt-

age startup circuit suitable for isolated telecom/industri-

al voltage range power supplies. Current-mode control

with leading-edge blanking simplifies control-loop

design and internal ramp compensation circuitry stabi-

lizes the current loop when operating at duty cycles

above 50% (MAX5014). The MAX5014 allows 85%

operating duty cycle and could be used to implement

flyback converters, whereas the MAX5015 limits the

operating duty cycle to less than 50% and can be used

in single-ended forward converters. A high-voltage

startup circuit allows these devices to draw power

directly from the 18V to 110V input supply during start-

up. The switching frequency is internally trimmed to

275kHz ±10%, thus reducing magnetics and filter com-

ponent costs.

The MAX5014/MAX5015 are available in 8-pin SO

packages. An evaluation kit (MAX5015EVKIT) is also

available.

Warning: The MAX5014/MAX5015 are designed to

operate with high voltages. Exercise caution.

Applications

Telecom Power Supplies

Industrial Power Supplies

Networking Power Supplies

Isolated Power Supplies

Features

o Wide Input Range: (18V to 110V) or (13V to 36V)

o Current-Mode Control

o Leading-Edge Blanking

o Internally Trimmed 275kHz ±10% Oscillator

o Low External Component Count

o Soft-Start

o High-Voltage Startup Circuit

o Pulse-by-Pulse Current Limiting

o Thermal Shutdown

o SO-8 Package

Current-Mode PWM Controllers with Integrated

Startup Circuit for Isolated Power Supplies

________________________________________________________________ Maxim Integrated Products

1

GND

CS

1

2

8

7

NDRV

OPTO

V+

8-SO

TOP VIEW

3

4

6

5

MAX5014/

MAX5015

SS_SHDN

Pin Configuration

Ordering Information

MAX5015

V+

SS_SHDN

NDRV

CS

GND

OPTO

OPTOCOUPLER

Typical Operating Circuit

19-2082; Rev 0; 7/01

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at

1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

EVALUATION

KIT

AVAILABLE

PART

TEMP. RANGE

PIN-PACKAGE

MAX5014CSA*

0

°C to +70°C8-SO

MAX5014ESA*

-40

°C to +85°C8-SO

MAX5015CSA*

0

°C to +70°C8-SO

MAX5015ESA*

-40

°C to +85°C8-SO

*See Selector Guide at end of data sheet.