MP1484EN-LF-Z

MP1484 3A, 18V, 340KHz Synchronous Rectified Step-Down Converter The Future of Analog IC Technology DESCRIPTION FEATURES The MP1484 is a monolithic synchronous buck 3A Continuous Output Current regulator. The device integrates top and bottom Wide 4.75V to 18V Operating Input Range 85m MOSFETS that provide 3A of continuous Integrated 85m Power MOSFET Switches load current over a wide operating input voltage Output Adjustable from 0.925V to 20V of 4.75V to 18V. Current mode control provides Up to 95% Efficiency fast transient response and cycle-by-cycle Programmable Soft-Start current limit. Stable with Low ESR Ceramic Output Capacitors An adjustable soft-start prevents inrush current Fixed 340KHz Frequency at turn-on and in shutdown mode, the supply Cycle-by-Cycle Over Current Protection current drops below 1A. Input Under Voltage Lockout Thermally Enhanced 8-Pin SOIC Package The MP1484 is PIN compatible to the MP1482 2A/18V/Synchronous Step-Down Converter. APPLICATIONS FPGA, ASIC, DSP Power Supplies LCD TV Green Electronics/Appliances Notebook Computers MPS and The Future of Analog IC Technology are Registered Trademarks of Monolithic Power Systems, Inc. TYPICAL APPLICATION Efficiency vs Load Current 100 V = 5V IN 95 V = 12V 2 1 IN 90 IN BS 7 3 85 EN SW 80 8 5 75 SS FB GND COMP 70 4 6 65 60 55 50 0.1 1.0 10 LOAD CURRENT (A) MP1484 Rev. 0.9 www.MonolithicPower.com 1 10/23/2008 MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. 2008 MPS. All Rights Reserved. EFFICIENCY (%)MP1484 3A, 18V, 340KHz SYNCHRONOUS RECTIFIED STEP-DOWN CONVERTER (1) PACKAGE REFERENCE ABSOLUTE MAXIMUM RATINGS Supply Voltage V .......................0.3V to +24V IN Switch Voltage V ................. 1V to V + 0.3V SW IN TOP VIEW Boost Voltage V ..........V 0.3V to V + 6V BS SW SW All Other Pins.................................0.3V to +6V BS 1 8 SS Junction Temperature...............................150C IN 2 7 EN Lead Temperature ....................................260C SW 3 6 COMP Storage Temperature .............65C to +150C GND 4 5 FB (2) Recommended Operating Conditions Input Voltage V ............................ 4.75V to 18V EXPOSED PAD IN ON BACKSIDE Output Voltage V .................... 0.925V to 20V OUT CONNECT Ambient Operating Temp .............. 20C to +85C TO GND PIN (3) Thermal Resistance JA JC SOIC8N(Exposed Pad) .......... 50...... 10... C/W Part Number* Package Temperature Notes: SOIC8N MP1484EN 20C to +85C 1) Exceeding these ratings may damage the device. (Exposed Pad) 2) The device is not guaranteed to function outside of its operating conditions. For Tape & Reel, add suffix Z (e.g. MP1484EN -Z) * 3) Measured on approximately 1 square of 1 oz copper. For Lead Free, add suffix LF (e.g. MP1484EN - LF-Z) ELECTRICAL CHARACTERISTICS V = 12V, T = +25C, unless otherwise noted. IN A Parameter SymbolCondition Min Typ Max Units Shutdown Supply Current V = 0V 0.3 3.0 A EN Supply Current V = 2.0V, V = 1.0V 1.3 1.5 mA EN FB Feedback Voltage V 4.75V V 18V 0.900 0.925 0.950 V FB IN Feedback Overvoltage Threshold 1.1 V (4) Error Amplifier Voltage Gain A 400 V/V EA Error Amplifier Transconductance G 820 A/V I = 10 A EA C High-Side/Low-Side Switch On- 85 m (4) Resistance High-Side Switch Leakage Current V = 0V, V = 0V 0 10 A EN SW Upper Switch Current Limit Minimum Duty Cycle 3.8 5.3 A Lower Switch Current Limit From Drain to Source 0.9 A COMP to Current Sense G 5.2 A/V CS Transconductance Oscillation Frequency F 300 340 380 KHz osc1 Short Circuit Oscillation Frequency F V = 0V 110 KHz osc2 FB Maximum Duty Cycle D V = 1.0V 90 % MAX FB (4) Minimum On Time T 220 ns ON EN Shutdown Threshold Voltage V Rising 1.1 1.5 2.0 V EN EN Shutdown Threshold Voltage 220 mV Hysterisis MP1484 Rev. 0.9 www.MonolithicPower.com 2 10/23/2008 MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. 2008 MPS. All Rights Reserved.