LT3573

1

3573f

FEATURES

APPLICATIONS

DESCRIPTION

Isolated Flyback Converter

Without an Opto-Coupler

cally designed for the isolated flyback topology. No third

winding or optoisolator is required for regulation. The

part senses the isolated output voltage directly from the

primary side flyback waveform. A 1.25A, 60V NPN power

switch is integrated along with all control logic into a 16-

lead MSOP package.

The LT3573 operates with input supply voltages from

3V to 40V, and can deliver output power up to 7W with

no external power devices.The LT3573 utilizes boundary

mode operation to provide a small magnetic solution with

improved load regulation.

5V Isolated Flyback Converter

Optoisolator Required for Regulation

Load Regulation

NPN Driver

LT, LTC and LTM are registered trademarks of Linear Technology Corporation.

All other trademarks are the property of their respective owners. Patents pending.

Load Regulation

SHDN/UVLO

TC

SS

SW

VC

GND

TEST BIAS

LT3573

3573 TA01

28.7k

10k

20k

12V TO 24V

+

5V, 0.7A

–

3:1

357k

51.1k

10nF

1nF

6.04k

2k

80.6k

B340A

1N4148

0

1

2

0

–1

400

800

200

600

1000 1200 1400

–2

–3

3

3573 TA01b

TYPICAL APPLICATION