ADP1823 Datasheet, PDF (2/32 Pages) Analog Devices – Dual, Interleaved, Step-Down DC-to-DC Controller with Tracking

ADP1823
TABLE OF CONTENTS
Features .............................................................................................. 1
Applications....................................................................................... 1
Typical Application Circuit ............................................................. 1
General Description ......................................................................... 1
Revision History ............................................................................... 2
Specifications..................................................................................... 3
Absolute Maximum Ratings............................................................ 5
ESD Caution.................................................................................. 5
Functional Block Diagram .............................................................. 6
Pin Configuration and Function Descriptions............................. 7
Typical Performance Characteristics ............................................. 9
Theory of Operation ...................................................................... 13
Input Power ................................................................................. 13
Start-Up Logic............................................................................. 13
Internal Linear Regulator .......................................................... 13
Oscillator and Synchronization ................................................ 13
Error Amplifier ........................................................................... 14
Soft Start ...................................................................................... 14
Power OK Indicator ................................................................... 14
REVISION HISTORY
11/06—Rev. 0 to Rev. A
Changes to Features and Applications Sections ........................... 1
Changes to Specifications Section.................................................. 3
Changes to Absolute Maximum Ratings Section......................... 5
Replaced Theory of Operation Section ....................................... 13
Added Feedback Voltage Divider Section ................................... 18
Changes to Ratiometric Tracking Section................................... 23
Replaced PCB Layout Guidelines Section................................... 25
Added Application Circuits Section............................................. 29
Changes to Ordering Guide .......................................................... 31
4/06—Revision 0: Initial Version
Tracking ....................................................................................... 14
MOSFET Drivers........................................................................ 15
Current Limit.............................................................................. 15
Applications Information .............................................................. 16
Selecting the Input Capacitor ................................................... 16
Selecting the MOSFETS ............................................................ 17
Setting the Current Limit .......................................................... 18
Feedback Voltage Divider ......................................................... 18
Compensating the Voltage Mode Buck Regulator................. 18
Soft Start ...................................................................................... 22
Voltage Tracking......................................................................... 22
Coincident Tracking .................................................................. 22
Ratiometric Tracking ................................................................. 23
Thermal Considerations............................................................ 24
PCB Layout Guidelines.................................................................. 25
LFCSP Package Considerations................................................ 26
Application Circuits ....................................................................... 29
Outline Dimensions ....................................................................... 31
Ordering Guide .......................................................................... 31
Rev. A | Page 2 of 32