18 V, 12 A Step-Down Regulator with Programmable Current Limit Data Sheet ADP2389/ADP2390 FEATURES TYPICAL APPLICATIONS CIRCUIT Input voltage: 4.5 V to 18 V VIN BST V PVIN IN C BST Continuous output current: 12 A C EN IN SW V OUT L PGOOD Integrated MOSFETs: 17 m high-side/4.5 m low-side C OUT ADP2389/ 0.6 V 0.5% reference voltage ADP2390 Programmable switching frequency range: 200 kHz to 2200 kHz R TOP FTW FB Enhanced transient response ILIM R BOT Programmable current limit with 10% accuracy RT COMP VREG R C Precision enable and power good R R R SS FTW ILIM T GND PGND External compensation and soft start C C C VREG SS C PFM mode (ADP2390 only) Start up into a precharged output Figure 1. Supported by the ADIsimPower design tool APPLICATIONS Communication infrastructure Networking and servers Industrial and instrumentation Healthcare and medical Intermediate power rail conversions DC-to-DC point of load applications GENERAL DESCRIPTION The ADP2389/ADP2390 are current mode control, synchronous The ADP2389/ADP2390 operates over a 40C to +125C step-down, dc-to-dc regulators. They integrate a 17 m hi gh -side junction temperature range and is available in 32-lead, 5 mm power MOSFET and a 4.5 m s ynchronous rectifier MOSFET to 5 mm LFCSP package. provide a high efficiency solution. The ADP2390 operates in pulse 100 frequency modulation (PFM) mode to improve the system 95 efficiency at light load. The ADP2389/ADP2390 run from an 90 input voltage of 4.5 V to 18 V and can deliver up to 12 A of output current. The output voltage can be adjusted to 0.6 V and the 85 switching frequency can be programmed between 200 kHz to 80 2200 kHz. The ADP2389/ADP2390 target high performance applications 75 that require high efficiency and design flexibility. External 70 compensation and soft start provide design flexibility. The power- V = 1.2V OUT V = 1.8V OUT good output and precision enable input provide simple and reliable 65 V = 3.3V OUT power sequencing. An enhanced transient response feature V = 5.0V OUT 60 improves the load transient performance, which reduces the 0 1 2 3 4 5 6 7 8 9 10 11 12 OUTPUT CURRENT (A) output capacitance. Programmable current limit allows the user to optimized the inductor design and provide a compact solution. Figure 2. ADP2389 Efficiency vs. Output Current, VIN = 12 V, fSW = 300 kHz Other key features include undervoltage lockout (UVLO), overvoltage protection (OVP), overcurrent protection (OCP), and thermal shutdown (TSD). 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 2015 Analog Devices, Inc. All rights reserved. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. Technical Support www.analog.com EFFICIENCY (%) 12192-002 12192-001ADP2389/ADP2390 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Undervoltage Lockout (UVLO) ............................................... 13 Applications ....................................................................................... 1 Thermal Shutdown .................................................................... 13 Typical Applications Circuit ............................................................ 1 Applications Information .............................................................. 14 General Description ......................................................................... 1 Input Capacitor Selection .......................................................... 14 Revision History ............................................................................... 2 Output Voltage Setting .............................................................. 14 Detailed Functional Block Diagram .............................................. 3 Inductor Selection ...................................................................... 14 Specif icat ions ..................................................................................... 4 Output Capacitor Selection....................................................... 15 Absolute Maximum Ratings ............................................................ 6 Programming Input Voltage UVLO ........................................ 15 Thermal Information ................................................................... 6 Compensation Design ............................................................... 15 ESD Caution .................................................................................. 6 Design Example .............................................................................. 17 Pin Configuration and Function Descriptions ............................. 7 Output Voltage Setting .............................................................. 17 Typical Performance Characteristics ............................................. 8 Frequency Setting ....................................................................... 17 Theory of Operation ...................................................................... 12 Inductor Selection ...................................................................... 17 Control Scheme .......................................................................... 12 Output Capacitor Selection....................................................... 17 PFM Mode (ADP2390 Only) .................................................... 12 Compensation Components ..................................................... 18 Precision Enable/Shutdown ...................................................... 12 Soft Start Time Program ........................................................... 18 Internal Regulator (VREG) ....................................................... 12 Input Capacitor Selection .......................................................... 18 Bootstrap Circuitry .................................................................... 12 Schematic for Design Example ................................................. 18 Oscillator ..................................................................................... 12 External Components Recommendation .................................... 19 Soft Start ...................................................................................... 13 Circuit Board Layout Recommendations ................................... 20 Fast Transient Response ............................................................ 13 Typical Application Circuits ......................................................... 22 Power Good ................................................................................. 13 Outline Dimensions ....................................................................... 23 Peak Current-Limit and Short-Circuit Protection ................. 13 Ordering Guide .......................................................................... 23 Overvoltage Protection (OVP) ................................................. 13 REVISION HISTORY 8/15Revision 0: Initial Version Rev. 0 Page 2 of 23