200 kHz, 1 A High Voltage Step-Down Switching Regulator Data Sheet ADP3050 FEATURES FUNCTIONAL BLOCK DIAGRAM BIAS IN Wide input voltage range: 3.6 V to 30 V 3 8 Adjustable and fixed (3.3 V, 5 V) output options CURRENT SENSE Integrated 1 A power switch 2.50V AMPLIFIER 6 SD REGULATOR Uses small surface-mount components Cycle-by-cycle current limiting GND 7 Peak input voltage (100 ms): 60 V Configurable as a buck, buck-boost, and SEPIC FREQUENCY CURRENT AND CURRENT LIMIT LIMIT regulator FOLDBACK Available in 8-lead SOIC package Supported by ADIsimPower design tool + 200kHz OSCILLATOR APPLICATIONS 2 BOOST FB 4 CMP Industrial power systems S Q DRIVER PC peripheral power systems 1 SWITCH Preregulator for linear regulators R Distributed power systems g m Automotive systems ADP3050 1.2V Battery chargers 5 COMP Figure 1. GENERAL DESCRIPTION The ADP3050 is a current mode monolithic buck (step down) The ADP3050 includes a shutdown input that places the device PWM switching regulator that contains a high current 1 A power in a low power mode, reducing the total supply current to under switch and all control, logic, and protection functions. It uses a 20 A. Internal protection features include thermal shutdown unique compensation scheme allowing the use of any type of circuitry and a cycle-by-cycle current limit for the power switch output capacitor (tantalum, ceramic, electrolytic, OS-CON). to provide complete device protection under fault conditions. Unlike some buck regulators, the design is not restricted to using The ADP3050 provides excellent line and load regulation, a specific type of output capacitor or ESR value. maintaining typically less than 3% output voltage accuracy A special boosted drive stage is used to saturate the NPN power over temperature and under all input voltage and output switch, providing a system efficiency higher than conventional current conditions. bipolar buck switchers. Further efficiency improvements are The ADP3050 is specified over the industrial temperature range obtained by using the low voltage regulated output to provide of 40C to +85C and is available in a thermally enhanced 8-lead the internal operating current of the device. A high switching (not Pb-free only) SOIC package and a standard 8-lead (Pb-free frequency allows the use of small external surface-mount compo- only) RoHS-compliant SOIC package. nents. A wide variety of standard off-the-shelf devices can be used, providing a great deal of design flexibility. A complete regulator design requires only a few external components. Rev. C Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. No Tel: 781.329.4700 www.analog.com license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Fax: 781.461.3113 20082012 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. 00125-001ADP3050 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Catch Diode Selection ............................................................... 13 Applications ....................................................................................... 1 Input Capacitor Selection .......................................................... 14 Functional Block Diagram .............................................................. 1 Discontinous Mode Ringing ..................................................... 14 General Description ......................................................................... 1 Setting the Output Voltage ........................................................ 14 Revision History ............................................................................... 2 Frequency Compensation ......................................................... 14 Specifications ..................................................................................... 3 Current Limit/Frequency Foldback ......................................... 15 Absolute Maximum Ratings ............................................................ 4 Bias Pin Connection .................................................................. 15 ESD Caution .................................................................................. 4 Boosted Drive Stage ................................................................... 15 Pin Configuration and Function Descriptions ............................. 5 Start-Up/Minimum Input Voltage ........................................... 15 Typical Performance Characteristics ............................................. 6 Thermal Considerations ............................................................ 16 Theory of Operation ...................................................................... 10 Board Layout Guidelines ............................................................... 17 Setting the Output Voltage ........................................................ 10 Typical Applications ................................................................... 17 Applications Information .............................................................. 11 Inverting (Buck Boost) Regulator ............................................ 18 ADIsimPower Design Tool ....................................................... 11 Outline Dimensions ....................................................................... 20 Inductor Selection ...................................................................... 11 Ordering Guide .......................................................................... 20 Output Capacitor Selection ....................................................... 12 REVISION HISTORY 6/12Rev. B to Rev. C Change to Features Section ............................................................. 1 Added ADIsimPower Design Tool Section ................................. 11 Changes to Ordering Guide .......................................................... 20 3/08Rev. A to Rev. B Updated Format .................................................................. Universal Changes to General Description Section ...................................... 1 Changes to Figure 3 and Figure 5 ................................................... 6 Changes to Table 2 ............................................................................ 4 Deleted Table 4 ................................................................................ 14 Changes to Table 5 .......................................................................... 15 Deleted Table 8 ................................................................................ 15 Deleted Table 7 ................................................................................ 16 Deleted Table 9 ................................................................................ 16 Changes to Boosted Drive Stage Section and Thermal Considerations Sections................................................................. 19 Changes to Figure 27 ...................................................................... 20 Changes to Ordering Guide .......................................................... 23 Rev. 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