20 V, 4 A Synchronous Step-Down Regulator with Low-Side Driver Data Sheet ADP2380 FEATURES TYPICAL APPLICATIONS CIRCUIT V Input voltage: 4.5 V to 20 V IN 1 16 PVIN BST Integrated 44 m high-side MOSFET L C V BST OUT 2 15 C IN PVIN SW 0.6 V 1% reference voltage over temperature 3 14 C OUT UVLO SW Continuous output current: 4 A ADP2380 FET 4 13 PGOOD LD Programmable switching frequency: 250 kHz to 1.4 MHz 12 5 C RT VREG VREG Synchronizes to external clock: 250 kHz to 1.4 MHz R OSC 6 11 SYNC PGND 180 out-of-phase synchronization 7 10 R Programmable UVLO EN/SS GND TOP C 8 9 SS Power-good output COMP FB External compensation R BOT C C EA R Internal soft start with external adjustable option C EA Startup into a precharged output Supported by ADIsimPower design tool C CP EA Figure 1. APPLICATIONS Communications infrastructure Networking and servers 100 Industrial and instrumentation 95 Healthcare and medical 90 Intermediate power rail conversion 85 DC-to-dc point of load application 80 75 70 65 60 V = 1.2V OUT V = 3.3V OUT 55 V = 5V OUT 50 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 OUTPUT CURRENT (A) Figure 2. Efficiency vs. Output Current, VIN = 12 V, fSW = 250 kHz GENERAL DESCRIPTION The ADP2380 is a current mode control, synchronous, step-down, External compensation and an adjustable soft start provide dc-to-dc regulator. It integrates a 44 m high-side power MOSFET design flexibility. The power-good output provides simple and and a low-side driver to provide a high efficiency solution. The reliable power sequencing. Additional features include ADP2380 runs from an input voltage of 4.5 V to 20 V and can programmable undervoltage lockout (UVLO), overvoltage deliver 4 A of output current. The output voltage can be adjusted protection (OVP), overcurrent protection (OCP), and thermal to 0.6 V to 90% of the input voltage. The switching frequency of shutdown (TSD). the ADP2380 can be programmed from 250 kHz to 1.4 MHz or The ADP2380 operates over the 40C to +125C junction fixed at 290 kHz or 540 kHz. The synchronization function allows temperature range and is available in a 16-lead TSSOP EP the switching frequency to be synchronized to an external clock package. to minimize system noise. Rev. 0 Document Feedback 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 2012 Analog Devices, Inc. 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Technical Support www.analog.com EFFICIENCY (%) 09939-002 09939-001ADP2380 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Applications Information .............................................................. 15 Applications ....................................................................................... 1 Input Capacitor Selection .......................................................... 15 Typical Applications Circuit ............................................................ 1 Output Voltage Setting .............................................................. 15 General Description ......................................................................... 1 Voltage Conversion Limitations ............................................... 15 Revision History ............................................................................... 2 Inductor Selection ...................................................................... 15 Specifications ..................................................................................... 3 Output Capacitor Selection....................................................... 17 Absolute Maximum Ratings ............................................................ 5 Low-Side Power Device Selection ............................................ 17 Thermal Information ................................................................... 5 Programming Input Voltage UVLO ........................................ 18 ESD Caution .................................................................................. 5 Compensation Design ............................................................... 18 Pin Configuration and Function Descriptions ............................. 6 ADIsimPower Design Tool ....................................................... 19 Typical Performance Characteristics ............................................. 7 Design Example .............................................................................. 20 Functional Block Diagram ............................................................ 12 Output Voltage Setting .............................................................. 20 Theory of Operation ...................................................................... 13 Frequency Setting ....................................................................... 20 Control Scheme .......................................................................... 13 Inductor Selection ...................................................................... 20 Internal Regulator (VREG) ....................................................... 13 Output Capacitor Selection....................................................... 20 Bootstrap Circuitry .................................................................... 13 Low-Side MOSFET Selection ................................................... 21 Low-Side Driver .......................................................................... 13 Compensation Components ..................................................... 21 Oscillator ..................................................................................... 13 Soft Start Time Program ........................................................... 21 Synchronization .......................................................................... 13 Input Capacitor Selection .......................................................... 21 Enable and Soft Start .................................................................. 13 Recommended External Components ........................................ 22 Power Good ................................................................................. 14 Circuit Board Layout Recommendations ................................... 24 Peak Current-Limit and Short-Circuit Protection ................. 14 Typical Applications Circuits ........................................................ 26 Overvoltage Protection (OVP) ................................................. 14 Outline Dimensions ....................................................................... 27 Undervoltage Lockout (UVLO) ............................................... 14 Ordering Guide .......................................................................... 27 Thermal Shutdown ..................................................................... 14 REVISION HISTORY 12/12Revision 0: Initial Version Rev. 0 Page 2 of 28