Datasheet ADP1822 (Analog Devices) - 2

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