ADP1621

Rev. A | Page 2 of 32

TABLE OF CONTENTS

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

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

General Description ......................................................................... 1

Typical Application Circuit ............................................................. 1

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

Specifications..................................................................................... 3

Absolute Maximum Ratings............................................................ 5

Thermal Resistance ...................................................................... 5

ESD Caution.................................................................................. 5

Simplified Block Diagram ............................................................... 6

Pin Configuration and Function Descriptions............................. 7

Typical Performance Characteristics ............................................. 8

Theory of Operation ...................................................................... 12

Control Loop............................................................................... 12

Current-Sense Configurations.................................................. 12

Current Limit .............................................................................. 13

Undervoltage Lockout ............................................................... 13

Shutdown..................................................................................... 13

Soft Start ...................................................................................... 13

Internal Shunt Regulators.......................................................... 13

Setting the Oscillator Frequency and Synchronization

Frequency .................................................................................... 13

Application Information: Boost Converter................................. 14

Duty Cycle ................................................................................... 14

Setting the Output Voltage........................................................ 14

Inductor Current Ripple............................................................ 14

Inductor Selection ...................................................................... 14

Input Capacitor Selection.......................................................... 15

Output Capacitor Selection....................................................... 15

Diode Selection........................................................................... 15

MOSFET Selection..................................................................... 16

Loop Compensation .................................................................. 16

Slope Compensation .................................................................. 17

Current Limit .............................................................................. 18

Light Load Operation ................................................................ 18

Recommended Component Manufacturers........................... 19

Layout Considerations................................................................... 20

Efficiency Considerations ............................................................. 21

Examples of Application Circuits................................................. 22

Standard Boost Converter—Design Example ........................ 22

Bootstrapped Boost Converter................................................. 23

SEPIC Converter Circuit ........................................................... 27

Low Voltage Power-Input Circuit ............................................ 27

LED Driver Application Circuits ............................................. 28

Related Parts.................................................................................... 30

Outline Dimensions ....................................................................... 31

Ordering Guide .......................................................................... 31

REVISION HISTORY

12/06—Rev.

0 to Rev. A

Changes to Table 1............................................................................ 3

Changes to Table 2............................................................................ 5

Added Table 3.................................................................................... 5

Changes to Table 5.......................................................................... 19

Changes to Ordering Guide .......................................................... 31

7/06—Revision 0: Initial Version