Datasheet

ADP1829 Data Sheet
Rev. C | Page 2 of 28
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
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 ................. 19
Soft Start ...................................................................................... 22
Voltage Tracking ......................................................................... 22
Coincident Tracking .................................................................. 23
Ratiometric Tracking ................................................................. 23
Thermal Considerations ............................................................ 24
PCB Layout Guidelines .................................................................. 25
LFCSP Package Considerations ................................................ 25
Application Circuits ....................................................................... 26
Outline Dimensions ....................................................................... 28
Ordering Guide .......................................................................... 28
REVISION HISTORY
10/12—Rev. B to Rev. C
Changes to PCB Layout Guidelines Section ............................... 25
Updated Outline Dimensions ....................................................... 28
Changes to Ordering Guide .......................................................... 28
1/11—Rev. A to Rev. B
Changes to VREG Short-Circuit Current Parameter, Table 1 .... 3
Changes to Figure 3 and Table 3 ..................................................... 7
Added Exposed Paddle Notation to Outline Dimensions ........ 29
4/09—Rev. 0 to Rev. A
Changes to Features and General Description Sections .............. 1
Changes to IN Input Voltage; EN1, IN2 Input High Voltage;
EN1, EN2 Input Low Voltage; and EN1, EN2 Input Impedance
to 5 V Zener Parameters, Table 1 ................................................... 3
Changes to Table 2 ............................................................................ 5
Changes to Table 3 ............................................................................ 7
Changes to Theory of Operation Section, Input Power Section,
and Start-Up Logic Section ........................................................... 13
Changes to Ordering Guide .......................................................... 29
6/07—Revision 0: Initial Version