Datasheet ADP2390 (Analog Devices)

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 Continuous output current: 12 A VIN PVIN CBST CIN EN SW V Integrated MOSFETs: 17 mΩ high-side/4.5 mΩ low-side PGOOD L OUT COUT 0.6 V ± 0.5% reference voltage ADP2389/ Programmable switching frequency range: 200 kHz to 2200 kHz ADP2390 RTOP Enhanced transient response FTW FB ILIM Programmable current limit with ±10% accuracy RT COMP RBOT Precision enable and power good VREG R R FTW RILIM RT SS C External compensation and soft start GND PGND C CSS C PFM mode (ADP2390 o nly) VREG C
001
Start up into a precharged output
12192-
Supported by the ADIsimPower d esign tool
Figure 1.
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 −40°C to +125°C step-down, dc-to-dc regulators. They integrate a 17 mΩ high-side junction temperature range and is available in 32-lead, 5 mm × power MOSFET and a 4.5 mΩ synchronous 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 input voltage of 4.5 V to 18 V and can deliver up to 12 A of output
90
current. The output voltage can be adjusted to 0.6 V and the
85
switching frequency can be programmed between 200 kHz to
(%)
2200 kHz.
80 ENCY
The ADP2389/ADP2390 target high performance applications
75 EFFICI
that require high efficiency and design flexibility. External compensation and soft start provide design flexibility. The power-
70 VOUT = 1.2V
good output and precision enable input provide simple and reliable
65 VOUT = 1.8V V
power sequencing. An enhanced transient response feature
OUT = 3.3V VOUT = 5.0V
improves the load transient performance, which reduces the
60 0 1 2 3 4 5 6 7 8 9 10 11 12
002 output capacitance. Programmable current limit al ows the user
OUTPUT CURRENT (A)
12192- 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).
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Document Outline FEATURES APPLICATIONS TYPICAL APPLICATIONS CIRCUIT GENERAL DESCRIPTION TABLE OF CONTENTS REVISION HISTORY DETAILED FUNCTIONAL BLOCK DIAGRAM SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS THERMAL INFORMATION ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS THEORY OF OPERATION CONTROL SCHEME PFM MODE (ADP2390 ONLY) PRECISION ENABLE/SHUTDOWN INTERNAL REGULATOR (VREG) BOOTSTRAP CIRCUITRY OSCILLATOR SOFT START FAST TRANSIENT RESPONSE POWER GOOD PEAK CURRENT-LIMIT AND SHORT-CIRCUIT PROTECTION OVERVOLTAGE PROTECTION (OVP) UNDERVOLTAGE LOCKOUT (UVLO) THERMAL SHUTDOWN APPLICATIONS INFORMATION INPUT CAPACITOR SELECTION OUTPUT VOLTAGE SETTING INDUCTOR SELECTION OUTPUT CAPACITOR SELECTION PROGRAMMING INPUT VOLTAGE UVLO COMPENSATION DESIGN DESIGN EXAMPLE OUTPUT VOLTAGE SETTING FREQUENCY SETTING INDUCTOR SELECTION OUTPUT CAPACITOR SELECTION COMPENSATION COMPONENTS SOFT START TIME PROGRAM INPUT CAPACITOR SELECTION SCHEMATIC FOR DESIGN EXAMPLE EXTERNAL COMPONENTS RECOMMENDATION CIRCUIT BOARD LAYOUT RECOMMENDATIONS TYPICAL APPLICATION CIRCUITS OUTLINE DIMENSIONS ORDERING GUIDE