2

LM3478

SNVS085X – JULY 2000 – REVISED DECEMBER 2017

www.ti.com

Product Folder Links: LM3478

Submit Documentation Feedback

Copyright © 2000–2017, Texas Instruments Incorporated

Table of Contents

1

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

2

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

3

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

4

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

5

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

6

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

6.1

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

6.2

ESD Ratings - LM3478 ............................................ 4

6.3

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

6.4

Thermal Information .................................................. 5

6.5

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

6.6

Typical Characteristics .............................................. 7

7

Detailed Description ............................................ 11

7.1

Overview ................................................................. 11

7.2

Functional Block Diagram ....................................... 12

7.3

Feature Description................................................. 12

7.4

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

8

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

8.1

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

8.2

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

9

Power Supply Recommendations ...................... 28

10

Layout................................................................... 28

10.1

Layout Guidelines ................................................. 28

10.2

Layout Example .................................................... 29

11

Device and Documentation Support ................. 30

11.1

Custom Design with WEBENCH Tools................. 30

11.2

Receiving Notification of Documentation Updates 30

11.3

Documentation Support ....................................... 30

11.4

Related Links ........................................................ 30

11.5

Trademarks ........................................................... 30

11.6

Electrostatic Discharge Caution ............................ 30

11.7

Glossary ................................................................ 30

12

Mechanical, Packaging, and Orderable

Information ........................................................... 31

4 Revision History

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

Changes from Revision W (December 2014) to Revision X

Page

•

Deleted LM3478Q-Q1 device. See LM3478Q-Q1 data sheet ............................................................................................... 1

•

Changed package from "DCK" to "DGK" for LM3478 and LM3478-Q1 devices in the Thermal Information table;

changed pin complement from "3" to "8" for the D, and DGK packages ............................................................................... 5

•

Changed RθJA for the D package from "157.2" to "105.3" °C/W............................................................................................. 5

•

Changed RθJC(top) for the D package from "49.9" to "50.3" °C/W............................................................................................ 5

•

Changed RθJB for the D package from "77.1" to "55.8" °C/W................................................................................................. 5

•

Changed ψJT for the D package from "4.7" to "6.8" °C/W ...................................................................................................... 5

•

Changed ψJB for the D package from "75.8" to "54.7" °C/W .................................................................................................. 5

Changes from Revision V (February 2013) to Revision W

Page

•

Added ESD Ratings table, Feature Description section, Device Functional Modes, Application and Implementation

section, Power Supply Recommendations section, Layout section, Device and Documentation Support section, and

Mechanical, Packaging, and Orderable Information section ................................................................................................. 4

•

Deleted Thermal Resistance parameter from Electrical Characteristics ............................................................................... 6

Changes from Revision U (February 2013) to Revision V

Page