link to page 1 link to page 1 link to page 1 link to page 1 link to page 2 link to page 3 link to page 5 link to page 5 link to page 5 link to page 6 link to page 7 link to page 14 link to page 15 link to page 15 link to page 16 link to page 16 link to page 16 link to page 16 link to page 17 link to page 17 link to page 17 link to page 17 link to page 18 link to page 18 link to page 18 link to page 19 link to page 19 link to page 21 link to page 21 link to page 21 link to page 21 link to page 23 link to page 23 link to page 24 link to page 25 link to page 25 link to page 26 link to page 29 link to page 29 link to page 29 link to page 30 link to page 31 link to page 32 link to page 32 ADP2441Data SheetTABLE OF CONTENTS Features .. 1 Applications Information .. 18 Applications ... 1 Selecting the Output Voltage .. 18 General Description ... 1 Setting the Switching Frequency .. 18 Typical Circuit Configuration ... 1 Soft Start .. 19 Revision History ... 2 External Components Selection ... 19 Specifications ... 3 Boost Capacitor .. 21 Absolute Maximum Ratings .. 5 VCC Capacitor.. 21 Thermal Resistance .. 5 Loop Compensation .. 21 ESD Caution .. 5 Large Signal Analysis of the Loop Compensation ... 21 Pin Configuration and Function Descriptions ... 6 Design Example .. 23 Typical Performance Characteristics ... 7 Configuration and Components Selection ... 23 Internal Block Diagram ... 14 System Configuration .. 24 Theory of Operation .. 15 Typical Application Circuits ... 25 Control Architecure ... 15 Design Example .. 25 Adjustable Frequency ... 16 Other Typical Circuit Configurations ... 26 Power Good ... 16 Power Dissipation and Thermal Considerations ... 29 Soft Start .. 16 Power Dissipation... 29 Tracking ... 16 Thermal Considerations .. 29 Undervoltage Lockout (UVLO) ... 17 Evaluation Board Thermal Performance .. 30 Precision Enable/Shutdown .. 17 Circuit Board Layout Recommendations ... 31 Current-Limit and Short-Circuit Protection .. 17 Outline Dimensions ... 32 Thermal Shutdown ... 17 Ordering Guide .. 32 REVISION HISTORY 8/15—Rev. B to Rev. C Changes to Figure 45 .. 14 6/14—Rev. A to Rev. B Change to Features Section ... 1 11/12—Rev. 0 to Rev. A Changes to Figure 1 .. 1 Changed IVIN Maximum Parameter from 2.2 mA to2 mA .. 3 Changes to Pin 3 and Pin 5 Descriptions .. 6 Changes to Boost Capacitor Section .. 21 Changes to Figure 66 .. 31 Changes to Ordering Guide .. 32 6/12—Revision 0: Initial Version Rev. C | Page 2 of 32 Document Outline FEATURES APPLICATIONS GENERAL DESCRIPTION TYPICAL CIRCUIT CONFIGURATION TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS INTERNAL BLOCK DIAGRAM THEORY OF OPERATION CONTROL ARCHITECURE Fixed Frequency Mode Pulse Skip Mode ADJUSTABLE FREQUENCY POWER GOOD SOFT START TRACKING Coincident Tracking Ratiometric Tracking UNDERVOLTAGE LOCKOUT (UVLO) PRECISION ENABLE/SHUTDOWN CURRENT-LIMIT AND SHORT-CIRCUIT PROTECTION THERMAL SHUTDOWN APPLICATIONS INFORMATION SELECTING THE OUTPUT VOLTAGE SETTING THE SWITCHING FREQUENCY SOFT START EXTERNAL COMPONENTS SELECTION Input Capacitor Selection Inductor Selection Output Capacitor Selection BOOST CAPACITOR VCC CAPACITOR LOOP COMPENSATION LARGE SIGNAL ANALYSIS OF THE LOOP COMPENSATION DESIGN EXAMPLE CONFIGURATION AND COMPONENTS SELECTION Resistor Divider Switching Frequency Soft Start Capacitor Inductor Selection Input Capacitor Selection Output Capacitor Selection Compensation Selection SYSTEM CONFIGURATION TYPICAL APPLICATION CIRCUITS DESIGN EXAMPLE OTHER TYPICAL CIRCUIT CONFIGURATIONS POWER DISSIPATION AND THERMAL CONSIDERATIONS POWER DISSIPATION Inductor Losses Power Switch Conduction Losses Switching Losses Transition Losses THERMAL CONSIDERATIONS EVALUATION BOARD THERMAL PERFORMANCE CIRCUIT BOARD LAYOUT RECOMMENDATIONS OUTLINE DIMENSIONS ORDERING GUIDE
