ADP3198

Rev. A | Page 2 of 32

TABLE OF CONTENTS

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

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

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

Functional Block Diagram .............................................................. 1

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

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

Test Circuits....................................................................................... 5

Absolute Maximum Ratings............................................................ 6

ESD Caution.................................................................................. 6

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

Typical Performance Characteristics ............................................. 9

Theory of Operation ...................................................................... 10

Start-Up Sequence...................................................................... 10

Phase Detection Sequence......................................................... 10

Master Clock Frequency............................................................ 11

Output Voltage Differential Sensing ........................................ 11

Output Current Sensing ............................................................ 11

Active Impedance Control Mode............................................. 11

Current Control Mode and Thermal Balance ........................ 11

Voltage Control Mode................................................................ 12

Current Reference ...................................................................... 12

Enhanced PWM Mode .............................................................. 12

Delay Timer................................................................................. 12

Soft Start ...................................................................................... 12

Current-Limit, Short-Circuit, and Latch-Off Protection...... 13

Dynamic VID.............................................................................. 13

Power-Good Monitoring........................................................... 14

Output Crowbar ......................................................................... 14

Output Enable and UVLO ........................................................ 14

Thermal Monitoring .................................................................. 14

Application Information................................................................ 20

Setting the Clock Frequency..................................................... 20

Soft Start Delay Time................................................................. 20

Current-Limit Latch-Off Delay Times .................................... 20

Inductor Selection ...................................................................... 21

Current Sense Amplifier............................................................ 22

Inductor DCR Temperature Correction ................................. 22

Output Offset .............................................................................. 24

COUT Selection ............................................................................. 24

Power MOSFETs......................................................................... 25

Ramp Resistor Selection............................................................ 26

COMP Pin Ramp ....................................................................... 26

Current-Limit Setpoint.............................................................. 26

Feedback Loop Compensation Design.................................... 27

CIN Selection and Input Current di/dt Reduction.................. 28

Thermal Monitor Design .......................................................... 28

Shunt Resistor Design................................................................ 29

Tuning the ADP3198 ................................................................. 29

Layout and Component Placement ......................................... 31

Outline Dimensions ....................................................................... 32

Ordering Guide .......................................................................... 32

REVISION HISTORY

8/06—Rev. 0 to Rev. A.

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

Changes to Table 2............................................................................ 6

Changes to Start-Up Sequence Section ....................................... 10

Changes to Phase Detection Sequence Section .......................... 10

6/06—Revision 0: Initial Version