General Description

The MAX5033 easy-to-use, high-efficiency, high-voltage,

step-down DC-DC converter operates from an input volt-

age up to 76V and consumes only 270µA quiescent cur-

rent at no load. This pulse-width modulated (PWM)

converter operates at a fixed 125kHz switching frequen-

cy at heavy loads, and automatically switches to pulse-

skipping mode to provide low quiescent current and

high efficiency at light loads. The MAX5033 includes

internal frequency compensation simplifying circuit

implementation. The device uses an internal low-on-

resistance, high-voltage, DMOS transistor to obtain high

efficiency and reduce overall system cost. This device

includes undervoltage lockout, cycle-by-cycle current

limit, hiccup-mode output short-circuit protection, and

thermal shutdown.

The MAX5033 delivers up to 500mA output current.

The output current may be limited by the maximum

power dissipation capability of the package. External

shutdown is included, featuring 10µA (typ) shutdown

current. The MAX5033A/B/C versions have fixed output

voltages of 3.3V, 5V, and 12V, respectively, while the

MAX5033D features an adjustable output voltage, from

1.25V to 13.2V.

The MAX5033 is available in space-saving 8-pin SO

and 8-pin plastic DIP packages and operates over the

automotive (-40°C to +125°C) temperature range.

Applications

Automotive

Consumer Electronics

Industrial

Distributed Power

Features

o Wide 7.5V to 76V Input Voltage Range

o Fixed (3.3V, 5V, 12V) and Adjustable (1.25V to

13.2V) Voltage Versions

o 500mA Output Current

o Efficiency Up to 94%

o Internal 0.4Ω High-Side DMOS FET

o 270µA Quiescent Current at No Load, 10µA

Shutdown Current

o Internal Frequency Compensation

o Fixed 125kHz Switching Frequency

o Thermal Shutdown and Short-Circuit Current Limit

o 8-Pin SO and PDIP Packages

500mA, 76V, High-Efficiency, MAXPower

Step-Down DC-DC Converter

________________________________________________________________ Maxim Integrated Products

1

Ordering Information

19-2979; Rev 2; 5/04

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.

PART

TEMP RANGE

PIN-

PACKAGE

OUTPUT

VOLTAGE

(V)

MAX5033AUSA

0

°C to +85°C

8 SO

MAX5033AUPA

0

°C to +85°C

8 PDIP

MAX5033AASA

-40

°C to +125°C 8 SO

3.3

MAX5033BUSA

0

°C to +85°C

8 SO

MAX5033BUPA

0

°C to +85°C

8 PDIP

MAX5033BASA

-40

°C to +125°C 8 SO

5.0

MAX5033CUSA

0

°C to +85°C

8 SO

MAX5033CUPA

0

°C to +85°C

8 PDIP

MAX5033CASA

-40

°C to +125°C 8 SO

12

MAX5033DUSA

0

°C to +85°C

8 SO

MAX5033DUPA

0

°C to +85°C

8 PDIP

MAX5033DASA

-40

°C to +125°C 8 SO

ADJ

1

2

3

4

BST

VD

SGND

FB

8

7

6

5

LX

GND

ON/OFF

MAX5033

SO/PDIP

Pin Configuration

MAX5033

GND

BST

LX

SGND

FB

D1

50SQ100

VD

220

µH

5V, 0.5A

7.5V TO 76V

47

µF

0.1

µF

0.1

µF

33

µF

ON

OFF

R1

R2

ON/OFF

Typical Operating Circuit