STR-G665

3

OFF-LINE

QUASI-RESONANT FLYBACK

SWITCHING REGULATOR

115 Northeast Cutoff, Box 15036

Worcester, Massachusetts 01615-0036 (508) 853-5000

™

Copyright © 1999 Allegro MicroSystems, Inc.

FUNCTIONAL BLOCK DIAGRAM

FEEDBACK &

OVER-CURRENT

PROTECTION

GROUND

V

IN

SOURCE

DRAIN

Dwg. FK-002-5

0.73 V

–

–

TSD

OVER-VOLT.

PROTECT

R

SQ

REF.

FAULT

LATCH

4

1

2

1.45 V

UVLO

+

5

+

3

DRIVE

REG.

OSC

ALLOWABLE PACKAGE POWER DISSIPATION

MAXIMUM SAFE OPERATING AREA

30

20

10

20

60

100

1.5 W

140

LIMITED BY FRAME

TEMP. = +125

°C MAX.

FREE AIR

27 W

0

TEMPERATURE in

°C

MOUNTING SURFACE

TEMPERATURE

Dwg. GK-003-4

0.8 W

CONTROLLER

50

5

0.5

0.05

DRAIN-SOURCE VOLTAGE in VOLTS

Dwg. GK-004-5

0.15

1.5

15

3.0

10

30

100

300

NO HEAT SINK

NATURAL COOLING

TA = +25

°C

tw =

1 ms

SINGLE

PULSE

1000

tw =

0.1

ms

SINGLE

PULSE

LIMITED

BY

rDS(on)