11

FN6899.0

December 22, 2009

Table of Contents

Applications Schematics: ISL95870.................................................................................................... 2

Applications Schematics: ISL95870A.................................................................................................. 3

Applications Schematics: ISL95870B.................................................................................................. 4

Block Diagram .................................................................................................................................... 5

ISL95870 Functional Pin Descriptions ................................................................................................ 7

ISL95870A Functional Pin Descriptions .............................................................................................. 8

ISL95870B Functional Pin Descriptions .............................................................................................. 9

Absolute Maximum Ratings .............................................................................................................. 12

Thermal Information ........................................................................................................................ 12

Recommended Operating Conditions ................................................................................................ 12

Electrical Specifications..................................................................................................................... 12

Theory of Operation.......................................................................................................................... 15

Power-On Reset .............................................................................................................................. 15

Start-Up Timing .............................................................................................................................. 15

Start-Up and Voltage-Step Operation for ISL95870.............................................................................. 15

Start-Up and Voltage-Step Operation for ISL95870A, ISL95870B........................................................... 15

Output Voltage Programming for ISL95870......................................................................................... 16

Output Voltage Programming for ISL95870A....................................................................................... 16

Output Voltage Programming for ISL95870B....................................................................................... 17

High Output Voltage Programming ..................................................................................................... 19

R4 Modulator.................................................................................................................................. 19

Stability ......................................................................................................................................... 19

Transient Response ......................................................................................................................... 20

Diode Emulation.............................................................................................................................. 20

Overcurrent.................................................................................................................................... 20

Overvoltage ................................................................................................................................... 21

Undervoltage.................................................................................................................................. 21

Over-Temperature........................................................................................................................... 21

PGOOD Monitor............................................................................................................................... 22

Integrated MOSFET Gate-Drivers ....................................................................................................... 22

Adaptive Shoot-Through Protection.................................................................................................... 22

General Application Design Guide ..................................................................................................... 22

Selecting the LC Output Filter ........................................................................................................... 22

Selecting the Input Capacitor ............................................................................................................ 23

Selecting the Bootstrap Capacitor...................................................................................................... 23

Driver Power Dissipation .................................................................................................................. 23

MOSFET Selection and Considerations ................................................................................................ 24

Layout Considerations ...................................................................................................................... 24

Revision History ............................................................................................................................... 26

Products ........................................................................................................................................... 26

L16.2.6x1.8A ..................................................................................................................................... 27

L20.3.2x1.8 ........................................................................................................................................ 28

L20.3x4.............................................................................................................................................. 29

ISL95870, ISL95870A, ISL95870B