Data Sheet

LT83203/LT83205

analog.com

Rev. B

2 of 44

TABLE OF CONTENTS

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

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

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

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

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

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

Pin Configurations and Function Descriptions........................................................................................................................................8

Typical Performance Characteristics .....................................................................................................................................................11

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

Theory of Operation ................................................................................................................................................................................19

Applications Information ........................................................................................................................................................................20

Low Frequency Output Noise.............................................................................................................................................................20

Filtering Switching Ripple and High Frequency Noise......................................................................................................................20

PCB Layout Recommendations..........................................................................................................................................................21

Forced Continuous Mode (FCM).........................................................................................................................................................23

Pulse-Skipping Mode ..........................................................................................................................................................................23

Synchronization ..................................................................................................................................................................................24

Setting the Switching Frequency .......................................................................................................................................................24

Operating Frequency Selection and Trade-Offs ...............................................................................................................................25

Inductor Selection and Maximum Output Current ...........................................................................................................................25

Overcurrent Protection (OCP) and Hiccup Mode..............................................................................................................................27

Input Capacitors..................................................................................................................................................................................27

Output Capacitor and Output Ripple.................................................................................................................................................27

Output Voltage ....................................................................................................................................................................................28

Output Voltages Above 13V ................................................................................................................................................................30

Output Voltages Below 0.5V ...............................................................................................................................................................30

Output Sensing and Stability .............................................................................................................................................................30

Frequency Compensation ..................................................................................................................................................................31

EN/UVLO Pin ........................................................................................................................................................................................31

INTVCC Regulator..................................................................................................................................................................................32

SET Pin Capacitor: Noise and Soft-Start............................................................................................................................................32

Fast Start-Up........................................................................................................................................................................................35

Programmable Power Good...............................................................................................................................................................35

Shorted and Reversed Input Protection............................................................................................................................................36