LTC3675

2

3675fa

TABLE OF CONTENTS

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

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

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

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

Absolute Maximum Ratings..................................................................................................... 3

Order Information................................................................................................................. 3

Pin Configuration ................................................................................................................. 3

Electrical Characteristics ........................................................................................................ 4

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

Pin Functions .....................................................................................................................14

Block Diagram....................................................................................................................16

Operation..........................................................................................................................17

Buck Switching Regulator .................................................................................................................................... 17

Buck Regulators with Combined Power Stages .................................................................................................... 17

Boost Switching Regulator ................................................................................................................................... 18

Buck-Boost Switching Regulator .......................................................................................................................... 18

LED Driver ............................................................................................................................................................ 18

Pushbutton Interface and Power-Up Power-Down Sequencing ............................................................................ 19

Power-Up and Power-Down via Pushbutton ......................................................................................................... 19

LED Current Programming ................................................................................................................................... 21

Error Condition Reporting via RSTB and IRQB Pins ............................................................................................. 24

Undervoltage and Overtemperature Functionality ................................................................................................. 25

Applications Information .......................................................................................................26

Switching Regulator Output Voltage and Feedback Network................................................................................. 26

Buck Regulators ................................................................................................................................................... 26

Combined Buck Regulators .................................................................................................................................. 26

Boost Regulator.................................................................................................................................................... 27

Buck-Boost Regulator........................................................................................................................................... 28

LED Driver ............................................................................................................................................................ 28

Operating the LED Driver As a High Voltage Boost Regulator............................................................................... 29

Input and Output Decoupling Capacitor Selection................................................................................................. 29

Programming the UVOT Register ......................................................................................................................... 30

Programming the RSTB and IRQB Mask Registers .............................................................................................. 30

Status Byte Read Back ......................................................................................................................................... 31

PCB Considerations .............................................................................................................................................. 31

Typical Applications .............................................................................................................33

Package Description ............................................................................................................36

Revision History .................................................................................................................37

Typical Application ..............................................................................................................38

Related Parts .....................................................................................................................38