Data Sheet

LT8350S

analog.com

Rev. A

2 of 36

TABLE OF CONTENTS

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

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

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

Simplified Application Diagram............................................................................................................................................................1

Revision History ....................................................................................................................................................................................3

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

Absolute Maximum Ratings ..................................................................................................................................................................7

Electrostatic Discharge (ESD)...........................................................................................................................................................7

ESD Ratings.......................................................................................................................................................................................8

ESD Caution ......................................................................................................................................................................................8

PACKAGE INFORMATION.......................................................................................................................................................................8

Typical Operating Characteristics ......................................................................................................................................................10

Pin Configurations and Function Descriptions ..................................................................................................................................15

PIN DESCRIPTIONS .........................................................................................................................................................................15

Block Diagram.....................................................................................................................................................................................18

Operation ............................................................................................................................................................................................19

Power Switch Control.....................................................................................................................................................................19

(1) Peak-Buck in Buck Region (VIN >> VOUT).................................................................................................................................20

(2) Peak-Buck in Buck-Boost Region (VIN ~> VOUT) ......................................................................................................................21

(3) Peak-Boost in Buck-Boost Region (VIN <~ VOUT).....................................................................................................................21

(4) Peak-Boost in Boost Region (VIN << VOUT) ..............................................................................................................................22

Main Control Loop ..........................................................................................................................................................................22

Light Load Current Operation ........................................................................................................................................................22

Internal Charge Path.......................................................................................................................................................................23

Shutdown and Power-On-Reset.....................................................................................................................................................23

Start-Up and Fault Protection........................................................................................................................................................23

Applications Information....................................................................................................................................................................25

Switching Frequency Selection......................................................................................................................................................25

Switching Frequency Setting .........................................................................................................................................................25

Spread Spectrum Frequency Modulation......................................................................................................................................26

Frequency Synchronization and Operation Mode Selection ........................................................................................................26

Maximum Output Current ..............................................................................................................................................................27

Inductor Selection ..........................................................................................................................................................................27

CIN and COUT Selection......................................................................................................................................................................28