Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are

implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

12 __________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 (408) 737-7600

© 1993 Maxim Integrated Products

Printed USA

is a registered trademark of Maxim Integrated Products.

High-Efficiency PWM, Step-Down

P-Channel DC-DC Controller

Additional Notes

When probing the MAX747 circuit, avoid shorting AV+

to GND (the two pins are adjacent to each other) as

this may cause the IC to malfunction due to large

ground currents. Also, the MAX747 may continue to

operate with AV+ disconnected, but erratic switching

waveforms will appear at EXT. Finally, due to its fast

switching and high drive capability requirements, EXT

is a low-impedance point that is not short-circuit

protected. Therefore, do not short EXT to any node

(including AGND and V+, which are adjacent to EXT)

to prevent damaging the device.

SUPPLIER

PHONE

FAX

INDUCTORS

Coiltronics

(305) 781-8900

(305) 782-4163

Sumida USA

(708) 956-0666

(708) 956-0702

Sumida Japan

81-3-3607-511

81-3-3607-5428

CAPACITORS

Kemet

(803) 963-6300

(803) 963-6322

Matsuo

(714) 969-2491

(714) 960-6492

Nichicon

(708) 843-7500

(708) 843-2798

Sprague

(603) 224-1961

(603) 224-1430

Sanyo USA

(619) 661-6322

Sanyo Japan

81-3-3837-6242

United Chemi-Con

(714) 255-9500

(714) 255-9400

DIODES

Motorola

(800) 521-6274

Nihon USA

(805) 867-2555

(805) 867-2698

Nihon Japan

81-3-3494-7411

81-3-3494-7414

POWER TRANSISTORS

Harris

(407) 724-3739

(407) 724-3937

International Rectifier

(213) 772-2000

(213) 772-9028

Siliconix

(408) 988-8000

(408) 727-5414

RESISTORS

IRC

(512) 992-7900

(512) 992-3377

Gowanda

(716) 532-2234

(716) 532-2702

Table 1. Component Suppliers

___________________Chip Topography

V+

AGND

EXT

SS

REF

SHDN

LBI LBO GND

CS

OUT

CC

FB

AV+

0.130"

(3.30mm)

0.080"

(2.03mm)

MAX747

SUBSTRATE CONNECTED TO V+;

TRANSISTOR COUNT: 508.