Datasheet ADP2387 (Analog Devices) - 7

Data Sheet ADP2387 PIN CONFIGURATION AND FUNCTION DESCRIPTIONS N GOOD SS ILIM RT P EN PVI 24 23 22 21 20 19 COMP 1 18 PVIN FB 2 17 25 PVIN VREG 3 GND 16 PVIN GND 4 15 BST 26 SW 5 14 SW SW SW 6 13 PGND 7 8 9 10 11 12 SW ND ND ND ND ND G G G G G P P P P P ADP2387 TOP VIEW (Not to Scale) NOTES 1. THE EXPOSED GND PAD MUST BE SOLDERED TO A LARGE, EXTERNAL, COPPER GND PLANE TO REDUCE THERMAL RESISTANCE. 2. THE EXPOSED SW PAD MUST BE CONNECTED TO THE SW PINS OF THE ADP2387 BY USING SHORT, WIDE TRACES, OR ELSE SOLDERED
004
TO A LARGE, EXTERNAL, COPPER SW PLANE TO REDUCE THERMAL RESISTANCE.
12643- Figure 4. Pin Configuration
Table 4. Pin Function Descriptions Pin No. Mnemonic Description
1 COMP Error Amplifier Output. Connect an RC network from COMP to GND. 2 FB Feedback Voltage Sense Input. Connect this pin to a resistor divider from the output voltage, VOUT. 3 VREG Output of the Internal 8 V Regulator. The control circuits are powered from this voltage. Place a 1 µF, X7R or X5R ceramic capacitor between this pin and GND. 4 GND Analog Ground. This pin is the return of the internal control circuit. 5 to 7, 14 SW Switch Node Outputs. Connect these pins to the output inductor. 8 to 13 PGND Power Ground. This pin is the return of the low-side power MOSFET. 15 BST Supply Rail for the High-Side Gate Drive. Place a 0.1 µF, X7R or X5R capacitor between SW and BST. 16 to 19 PVIN Power Inputs. Connect these pins to the input power source and connect a bypass capacitor between these pins and PGND. 20 EN Precision Enable Pin. An external resistor divider can set the turn on threshold. To enable the device automatically, connect the EN pin to the PVIN pin. 21 PGOOD Power-Good Output (Open Drain). Connecting a pull-up resistor of 10 kΩ to 100 kΩ to this pin is recommended. 22 RT Frequency Setting. Connect a resistor between RT and GND to program the switching frequency between 200 kHz to 1400 kHz. 23 ILIM Current-Limit Threshold Setting. Connect a resistor between ILIM and GND to program the current-limit threshold. 24 SS Soft Start Control. Connect a capacitor from SS to GND to program the soft start time. If this pin is open, the regulator uses the internal soft start time. 25 EP, GND The exposed GND pad must be soldered to a large, external, copper GND plane to reduce thermal resistance. 26 EP, SW The exposed SW pad must be connected to the SW pins of the ADP2387 by using short, wide traces, or else soldered to a large, external copper SW plane to reduce thermal resistance. Rev. C | Page 7 of 25 Document Outline FEATURES APPLICATIONS TYPICAL APPLICATIONS CIRCUIT GENERAL DESCRIPTION TABLE OF CONTENTS REVISION HISTORY FUNCTIONAL BLOCK DIAGRAM SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS THERMAL RESISTANCE ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS THEORY OF OPERATION CONTROL SCHEME PRECISION ENABLE/SHUTDOWN INTERNAL REGULATOR (VREG) BOOTSTRAP CIRCUITRY OSCILLATOR SOFT START 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 VOLTAGE CONVERSION LIMITATIONS INDUCTOR SELECTION OUTPUT CAPACITOR SELECTION PROGRAMMING INPUT VOLTAGE UVLO COMPENSATION DESIGN ADIsimPower DESIGN TOOL DESIGN EXAMPLE OUTPUT VOLTAGE SETTING FREQUENCY SETTING CURRENT-LIMIT THRESHOLD SETTING INDUCTOR SELECTION OUTPUT CAPACITOR SELECTION COMPENSATION COMPONENTS SOFT START TIME PROGRAM INPUT CAPACITOR SELECTION RECOMMENDED EXTERNAL COMPONENTS CIRCUIT BOARD LAYOUT RECOMMENDATIONS TYPICAL APPLICATIONS CIRCUITS OUTLINE DIMENSIONS ORDERING GUIDE