Datasheet ADP1829 (Analog Devices) - 2

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ADP1829 Data Sheet TABLE OF CONTENTS
Features .. 1 Tracking ... 14 Applications ... 1 MOSFET Drivers .. 15 Typical Application Circuit ... 1 Current Limit .. 15 General Description ... 1 Applications Information .. 16 Revision History ... 2 Selecting the Input Capacitor ... 16 Specifications ... 3 Selecting the MOSFETs ... 17 Absolute Maximum Ratings .. 5 Setting the Current Limit .. 18 ESD Caution .. 5 Feedback Voltage Divider ... 18 Functional Block Diagram .. 6 Compensating the Voltage Mode Buck Regulator ... 19 Pin Configuration and Function Descriptions ... 7 Soft Start .. 22 Typical Performance Characteristics ... 9 Voltage Tracking ... 22 Theory of Operation .. 13 Coincident Tracking .. 23 Input Power ... 13 Ratiometric Tracking ... 23 Start-Up Logic ... 13 Thermal Considerations .. 24 Internal Linear Regulator .. 13 PCB Layout Guidelines .. 25 Oscillator and Synchronization .. 13 LFCSP Package Considerations .. 25 Error Amplifier ... 14 Application Circuits ... 26 Soft Start .. 14 Outline Dimensions ... 28 Power OK Indicator ... 14 Ordering Guide .. 28
REVISION HISTORY 4/16—Rev. C to Rev. D 4/09—Rev. 0 to Rev. A
Changes to Figure 3 .. 7 Changes to Features and General Description Sections .. 1 Updated Outline Dimensions ... 28 Changes to IN Input Voltage; EN1, IN2 Input High Voltage; Changes to Ordering Guide .. 28 EN1, EN2 Input Low Voltage; and EN1, EN2 Input Impedance to 5 V Zener Parameters, Table 1 .. 3
10/12—Rev. B to Rev. C
Changes to Table 2 ... 5 Changes to PCB Layout Guidelines Section ... 25 Changes to Table 3 ... 7 Updated Outline Dimensions ... 28 Changes to Theory of Operation Section, Input Power Section, Changes to Ordering Guide .. 28 and Start-Up Logic Section ... 13 Changes to Ordering Guide .. 29
1/11—Rev. A to Rev. B
Changes to VREG Short-Circuit Current Parameter, Table 1 .. 3
6/07—Revision 0: Initial Version
Changes to Figure 3 and Table 3 ... 7 Added Exposed Paddle Notation to Outline Dimensions .. 29 Rev. D | Page 2 of 28 Document Outline FEATURES APPLICATIONS TYPICAL APPLICATION CIRCUIT GENERAL DESCRIPTION TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS ESD CAUTION FUNCTIONAL BLOCK DIAGRAM PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS THEORY OF OPERATION INPUT POWER START-UP LOGIC INTERNAL LINEAR REGULATOR OSCILLATOR AND SYNCHRONIZATION ERROR AMPLIFIER SOFT START POWER OK INDICATOR TRACKING MOSFET DRIVERS CURRENT LIMIT APPLICATIONS INFORMATION SELECTING THE INPUT CAPACITOR Selecting the Output LC Filter SELECTING THE MOSFETS SETTING THE CURRENT LIMIT FEEDBACK VOLTAGE DIVIDER COMPENSATING THE VOLTAGE MODE BUCK REGULATOR Type II Compensator Type III Compensator SOFT START VOLTAGE TRACKING COINCIDENT TRACKING RATIOMETRIC TRACKING Setting the Channel 2 Undervoltage Threshold for Ratiometric Tracking THERMAL CONSIDERATIONS PCB LAYOUT GUIDELINES LFCSP PACKAGE CONSIDERATIONS APPLICATION CIRCUITS OUTLINE DIMENSIONS ORDERING GUIDE