Datasheet

ADP1822 Data Sheet
Rev. D | Page 2 of 24
TABLE OF CONTENTS
Features .............................................................................................. 1
Applications ....................................................................................... 1
General Description ......................................................................... 1
Revision History ............................................................................... 2
Specifications ..................................................................................... 3
Absolute Maximum Ratings ............................................................ 5
ESD Caution .................................................................................. 5
Simplified Block Diagram ............................................................... 6
Pin Configuration and Function Descriptions ............................. 7
Typical Performance Characteristics ............................................. 9
Theory of Operation ...................................................................... 12
Current-Limit Scheme ............................................................... 12
Output Voltage Margining ........................................................ 12
Output Voltage Tracking ........................................................... 12
Soft Start ...................................................................................... 12
High-Side Driver (BST and DH) .............................................. 13
Low-Side Driver (DL) ................................................................ 13
Input Voltage Range ................................................................... 13
Setting the Output Voltage ........................................................ 13
Switching Frequency Control ................................................... 13
Compensation ............................................................................. 13
Power-Good Indicator ............................................................... 13
Shutdown Control ...................................................................... 13
Application Information ................................................................ 14
Selecting the Input Capacitor ................................................... 14
Output LC Filter ......................................................................... 14
Selecting the MOSFETS ............................................................ 15
Setting the Current Limit .......................................................... 15
Feedback Voltage Divider ......................................................... 16
Setting the Voltage Margin ........................................................ 16
Compensating the Regulator .................................................... 16
Setting the Soft Start Period ...................................................... 18
Synchronizing the Converter .................................................... 19
Setting the Output Voltage Tracking ....................................... 19
Application Circuits ....................................................................... 20
Outline Dimensions ....................................................................... 21
Ordering Guide .......................................................................... 21
REVISION HISTORY
12/11—Rev. C to Rev. D
Updated Outline Dimensions ....................................................... 21
Changes to Ordering Guide .......................................................... 21
5/07—Re v. B to Rev. C
Changes to Features .......................................................................... 1
Changes to General Description .................................................... 1
Changes to Specifications Section .................................................. 3
Changes to Table 2 ............................................................................ 5
Changes to Theory of Operation Section .................................... 12
Changes to Current Limit Scheme Section ................................. 12
Changes to Setting the Current Limit Section ............................ 15
Changes to Ordering Guide .......................................................... 21
8/06—Rev. A to Rev. B
Change to Title .................................................................................. 1
Change to General Description ...................................................... 1
Changes to Figure 6 .......................................................................... 9
Changes to Output Voltage Margining Section .......................... 12
Changes to Table 4 .......................................................................... 12
1/06—Re v. 0 to Re v. A
Changes to Figure 1 ........................................................................... 1
Changes to Table 1 ............................................................................. 3
Changes to Input Voltage Range Section .................................... 13
Changes to Selecting the Input Capacitor Section ..................... 14
Added Equation 1; Renumbered Sequentially ........................... 14
Changes to Equation 7 and Equation 8 ....................................... 15
Changes to Selecting the MOSFETS Section .............................. 15
Added Equation 9; Renumbered Sequentially ........................... 15
Changes to Equation 10 ................................................................. 15
Changes to Equation 22 ................................................................. 17
Changes to Compensating the Regulator Section ...................... 17
Changes to Figure 19 and Figure 20............................................. 17
Changes to Equation 27 ................................................................. 17
Changes to Equation 34 ................................................................. 18
7/05—Revision 0: Initial Version