Constant Frequency Current-Mode Step-Down DC-to-DC Controller in TSOT Data Sheet ADP1864 FEATURES GENERAL DESCRIPTION Wide input voltage range: 3.15 V to 14 V The ADP1864 is a compact, inexpensive, constant-frequency, Wide output voltage range: 0.8 V to input voltage current-mode, step-down dc-to-dc controller. The ADP1864 Pin-to-pin compatible with LTC1772, LTC3801 drives a P-channel MOSFET that regulates an output voltage as Up to 94% efficiency low as 0.8 V with 1.25% accuracy, for up to 5 A load currents, 0.8 V 1.25% reference accuracy over temperature from input voltages as high as 14 V. Internal soft start The ADP1864 provides system flexibility by allowing accurate 100% duty cycle for low dropout voltage setting of the current limit with an external resistor, and the Current-mode operation for good line and load output voltage is easily adjustable using two external resistors. transient response The ADP1864 includes an internal soft start to allow quick 7 A shutdown supply current power-up while preventing input inrush current. Additional 235 A quiescent supply current safety features include short-circuit protection, output overvoltage Short-circuit and overvoltage protection protection, and input undervoltage protection. Current-mode Small 6-lead TSOT package control provides fast and stable load transient performance, Supported by ADIsimPower design tool while the 580 kHz operating frequency allows a small inductor to be used in the system. To further the life of a battery source, APPLICATIONS the controller turns on the external P-channel MOSFET 100% of the duty cycle during dropout. Wireless devices 1- to 3-cell Li-Ion battery-powered applications The ADP1864 operates over the 40C to +125C temperature Set-top boxes range and is available in a small, low profile, 6-lead TSOT package. Processor core power supplies Hard disk drives TYPICAL APPLICATIONS DIAGRAM 25k COMP 1 PGATE 6 V = 3.15V TO 14V IN 470pF 68pF ADP1864 0. 03 10F 2 GND 5 IN 5H 80. 6k 2.5V, 2.0A 3 FB 4 CS 47F 174k Figure 1. Rev. C 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. 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All rights reserved. 05562-001ADP1864 Data Sheet TABLE OF CONTENTS Soft Start .........................................................................................9 Features .............................................................................................. 1 Applications Information .............................................................. 10 Applications ....................................................................................... 1 Duty Cycle ................................................................................... 10 General Description ......................................................................... 1 Ripple Current ............................................................................ 10 Typical Applications Diagram ........................................................ 1 Sense Resistor.............................................................................. 10 Revision History ............................................................................... 2 Inductor Value ............................................................................ 10 Specifications ..................................................................................... 3 MOSFET ...................................................................................... 11 Absolute Maximum Ratings ............................................................ 4 Diode ............................................................................................ 11 ESD Caution .................................................................................. 4 Input Capacitor ........................................................................... 11 Pin Configuration and Function Descriptions ............................. 5 Output Capacitor ........................................................................ 11 Typical Performance Characteristics ............................................. 6 Feedback Resistors ..................................................................... 11 Theory of Operation ........................................................................ 8 Layout Considerations ................................................................... 12 Loop Startup .................................................................................. 8 Example Applications Circuits ..................................................... 13 Short-Circuit Protection .............................................................. 9 Outline Dimensions ....................................................................... 14 Undervoltage Lockout (UVLO) ................................................. 9 Ordering Guide .......................................................................... 14 Overvoltage Lockout Protection (OVP).................................... 9 REVISION HISTORY 8/12Rev. B to Rev. C Change to Features Section ............................................................. 1 Added ADIsimPower Design Tool Section ................................. 10 Updated Outline Dimensions ....................................................... 14 Changes to Ordering Guide .......................................................... 14 4/08Rev. A to Rev. B Change General Description Section ............................................. 1 Deleted Figure 2 ................................................................................ 1 Change to FB Regulation Voltage Parameter ................................ 3 Change to MOSFET Section ......................................................... 11 Changes to Ordering Guide .......................................................... 14 2/07Rev 0. to Rev. A Updated Format .................................................................. Universal Changes to Figure 1 .......................................................................... 1 Changes to General Description .................................................... 2 Changes to Specifications ................................................................ 3 Change to Figure 13 ......................................................................... 8 Replaced Layout Considerations Section .................................... 12 Replaced Example Applications Circuits Section ...................... 13 10/05Revision 0: Initial Version Rev. C Page 2 of 16