20 V, 4 A, Synchronous, Step-Down DC-to-DC Regulator Data Sheet ADP2384 FEATURES TYPICAL APPLICATIONS CIRCUIT Input voltage: 4.5 V to 20 V ADP2384 Integrated MOSFET: 44 m/11.6 m BST V PVIN IN C BST L Reference voltage: 0.6 V 1% C IN EN SW V OUT Continuous output current: 4 A C OUT PGOOD R TOP Programmable switching frequency: 200 kHz to 1.4 MHz SYNC FB Synchronizes to external clock: 200 kHz to 1.4 MHz RT 180 out-of-phase clock synchronization COMP R T R R VREG C BOT Precision enable and power good SS C VREG GND PGND C C External compensation SS C Internal soft start with external adjustable option Startup into a precharged output Figure 1. Supported by ADIsimPower design tool APPLICATIONS Communications infrastructure Networking and servers Industrial and instrumentation Healthcare and medical Intermediate power rail conversion DC-to-dc point-of-load applications GENERAL DESCRIPTION The ADP2384 is a synchronous, step-down dc-to-dc regulator Other key features include undervoltage lockout (UVLO), with an integrated 44 m , high-side power MOSFET and overvoltage protection (OVP), overcurrent protection (OCP), an 11.6 m , synchronous rectifier MOSFET to provide a high short-circuit protection (SCP), and thermal shutdown (TSD). efficiency solution in a compact 4 mm 4 mm LFCSP package. The ADP2384 operates over the 40C to +125C junction This device uses a peak current mode, constant frequency pulse- temperature range and is available in a 24-lead, 4 mm 4 mm width modulation (PWM) control scheme for excellent stability LFCSP package. and transient response. The switching frequency of the ADP2384 100 can be programmed from 200 kHz to 1.4 MHz. To minimize 95 system noise, the synchronization function allows the switching 90 frequency to be synchronized to an external clock. 85 The ADP2384 requires minimal external components and operates 80 from an input voltage of 4.5 V to 20 V. The output voltage can be 75 adjusted from 0.6 V to 90% of the input voltage and delivers up to 70 4 A of continuous current. Each IC draws less than 120 A current from the input source when it is disabled. 65 60 This regulator targets high performance applications that require V = 1.2V OUT V = 3.3V OUT high efficiency and design flexibility. External compensation and an 55 V = 5V OUT adjustable soft start function provide design flexibility. The power- 50 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 good output and precision enable input provide simple and reliable OUTPUT CURRENT (A) power sequencing. Figure 2. Efficiency vs. Output Current, V = 12 V, f = 300 kHz IN SW Rev. 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Technical Support www.analog.com EFFICIENCY (%) 10725-002 10725-001ADP2384 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Thermal Shutdown .................................................................... 14 Applications ....................................................................................... 1 Applications Information .............................................................. 15 Typical Applications Circuit ............................................................ 1 Input Capacitor Selection .......................................................... 15 General Description ......................................................................... 1 Output Voltage Setting .............................................................. 15 Revision History ............................................................................... 2 Voltage Conversion Limitations ............................................... 15 Specifications ..................................................................................... 3 Inductor Selection ...................................................................... 15 Absolute Maximum Ratings ............................................................ 5 Output Capacitor Selection....................................................... 16 Thermal Resistance ...................................................................... 5 Programming the Input Voltage UVLO .................................. 17 ESD Caution .................................................................................. 5 Compensation Design ............................................................... 17 Pin Configuration and Function Descriptions ............................. 6 ADIsimPower Design Tool ....................................................... 18 Typical Performance Characteristics ............................................. 7 Design Example .............................................................................. 19 Functional Block Diagram ............................................................ 11 Output Voltage Setting (Design Example) .............................. 19 Theory of Operation ...................................................................... 12 Frequency Setting ....................................................................... 19 Control Scheme .......................................................................... 12 Inductor Selection (Design Example) ..................................... 19 Precision Enable/Shutdown ...................................................... 12 Output Capacitor Selection (Design Example) ...................... 20 Internal Regulator (VREG) ....................................................... 12 Compensation Components ..................................................... 20 Bootstrap Circuitry .................................................................... 12 Soft Start Time Program ........................................................... 20 Oscillator ..................................................................................... 12 Input Capacitor Selection (Design Example) ......................... 20 Synchronization .......................................................................... 12 Recommended External Components .................................... 21 Soft Start ...................................................................................... 13 Circuit Board Layout Recommendations ................................... 22 Power Good ................................................................................. 13 Typical Applications Circuits ........................................................ 23 Peak Current-Limit and Short-Circuit Protection ................. 13 Outline Dimensions ....................................................................... 24 Overvoltage Protection (OVP) ................................................. 14 Ordering Guide .......................................................................... 24 Undervoltage Lockout (UVLO) ............................................... 14 REVISION HISTORY 7/14Rev. 0 to Rev. A Changes to Table 2 and Table 3 ....................................................... 5 Changes to Inductor Selection Section ........................................ 15 Changes to Compensation Components Section....................... 20 Updated Outline Dimensions ....................................................... 24 8/12Revision 0: Initial Version Rev. A Page 2 of 24