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LM5181

SNVSBM6 – APRIL 2020

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Copyright © 2020, Texas Instruments Incorporated

Table of Contents

1

Features .................................................................. 1

2

Applications ........................................................... 1

3

Description ............................................................. 1

4

Revision History..................................................... 2

5

Description (continued)......................................... 2

6

Pin Configuration and Functions ......................... 3

7

Specifications......................................................... 4

7.1

Absolute Maximum Ratings ...................................... 4

7.2

ESD Ratings.............................................................. 4

7.3

Recommended Operating Conditions ....................... 4

7.4

Thermal Information .................................................. 4

7.5

Electrical Characteristics........................................... 5

7.6

Typical Characteristics .............................................. 6

8

Detailed Description .............................................. 9

8.1

Overview ................................................................... 9

8.2

Functional Block Diagram ......................................... 9

8.3

Feature Description................................................... 9

8.4

Device Functional Modes........................................ 15

9

Application and Implementation ........................ 16

9.1

Application Information............................................ 16

9.2

Typical Applications ................................................ 16

10

Power Supply Recommendations ..................... 22

11

Layout................................................................... 23

11.1

Layout Guidelines ................................................. 23

11.2

Layout Examples................................................... 24

12

Device and Documentation Support ................. 25

12.1

Device Support...................................................... 25

12.2

Documentation Support ....................................... 26

12.3

Receiving Notification of Documentation Updates 26

12.4

Support Resources ............................................... 26

12.5

Trademarks ........................................................... 26

12.6

Electrostatic Discharge Caution ............................ 27

12.7

Glossary ................................................................ 27

13

Mechanical, Packaging, and Orderable

Information ........................................................... 27

4 Revision History

NOTE: Page numbers for previous revisions may differ from page numbers in the current version.

DATE

REVISION

NOTES

April 2020

*

Initial release

5 Description (continued)

The LM5181 flyback converter simplifies implementation of isolated DC/DC supplies with optional features to

optimize performance for the target end equipment. The output voltage is set by one resistor, while an optional

resistor improves output voltage accuracy by negating the thermal coefficient of the flyback diode voltage drop.

Additional features include an internally-fixed or externally-programmable soft start, optional bias supply

connection for higher efficiency, precision enable input with hysteresis for adjustable line UVLO, hiccup-mode

overload protection, and thermal shutdown protection with automatic recovery.