MP38894DN-LF-Z Monolithic Power Systems

MP38894 4.5A, 42V, 420kHz Step-Down Converter with Synchronizable Gate Driver The Future of Analog IC Technology DESCRIPTION FEATURES The MP38894 is a monolithic step-down switch Wide 4.5V to 42V Operating Input Range mode converter with a built in internal power 4.5A Continuous Output Current MOSFET. It achieves 4.5A continuous output 1.5% Vfb Accuracy current over a wide input supply range with 100m Internal Power MOSFET Switch excellent load and line regulation. Synchronizable Gate Driver Delivers up to 95% Efficiency Current mode operation provides fast transient Fixed 420kHz Frequency response and eases loop stabilization. Synchronizable up to 1.5MHz Fault condition protection includes cycle-by-cycle Cycle-by-Cycle Over Current Protection with current limiting and thermal shutdown. Hiccup retry The MP38894 requires a minimum number of Thermal Shutdown readily available standard external components Output Adjustable from 0.8V to 15V and is available in an 8-pin SOIC package with Stable with Low ESR Output Ceramic exposed pad. Capacitors Available in a Thermally Enhanced 8-Pin SOIC Package APPLICATIONS Digital Set Top Boxes Personal Video Recorders Broadband Communications Flat Panel Television and Monitors MPS and The Future of Analog IC Technology are Registered Trademarks of Monolithic Power Systems, Inc. TYPICAL APPLICATION 8 2 V IN BST IN 1 SW 3 VCC M2 4 BG 7 6 EN/SYNC FB OFF ON GND 5 MP38894 Rev.1.0 www.MonolithicPower.com 1 9/28/2009 MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. 2009 MPS. All Rights Reserved. MP38894 4.5A, 42V, 420KHZ STEP-DOWN WITH SYNCHRONIZABLE GATE DRIVER (1) PACKAGE REFERENCE ABSOLUTE MAXIMUM RATINGS Supply Voltage V ....................................... 45V IN V ......................... 0.3V(-5V for <10ns) to 46V SW V V ...................................................... 6V BST SW TOP VIEW All Pins...........................................0.3V to +6V Junction Temperature...............................150C SW 1 8 IN Lead Temperature ....................................260C BST 2 7 EN/SYNC Storage Temperature ..............65 C to +150 C (2) VCC 3 6 FB Recommended Operating Conditions BG 4 5 GND Supply Voltage V ........................... 4.5V to 42V IN Output Voltage V ........................ 0.8V to 15V OUT EXPOSED PAD Operating Temperature .............40 C to +85 C ON BACKSIDE (3) Thermal Resistance JA JC SOIC8E .................................. 50...... 10... C/W Part Number* Package Temperature Notes: MP38894DN SOIC8E 40 C to +85C 1) Exceeding these ratings may damage the device. 2) The device is not guaranteed to function outside of its For Tape & Reel, add suffix Z (eg. MP38894DNZ) * operating conditions. For RoHS Compliant Packaging, add suffix LF 3) Measured on JESD51-7, 4-layer PCB. (eg. MP38894DNLFZ) ELECTRICAL CHARACTERISTICS V = 12V, T = +25 C, unless otherwise noted. IN A Parameters SymbolCondition Min Typ Max Units Feedback Voltage V 0.796 0.808 0.820 V 4.5V V 42V FB IN Feedback Current I V = 0.8V 10 nA FB FB (4) Switch On Resistance R 100 m DS(ON) Switch Leakage V = 0V, V = 0V 0.1 10 A EN SW (4) Current Limit I Duty=40% 6.5 A O-MAX Oscillator Frequency f V = 0.6V 240 420 600 kHz SW FB Fold-back Frequency V = 0V 25 115 205 kHz FB Maximum Duty Cycle V = 0.6V 85 90 % FB (4) Minimum On Time t 100 ns ON Under Voltage Lockout Threshold Rising 3.90 4.10 4.30 V Under Voltage Lockout Threshold Hysteresis 880 mV EN Input Low Voltage 0.4 V EN Input High Voltage 2 V V = 2V 2 EN EN Input Current A V = 0V 0.1 EN Sync Frequency Range (Low) F 300 kHz SYNCL Sync Frequency Range (High) F 1.5 MHz SYNCH Enable Turnoff Delay T 5.0 s OFF Supply Current (Shutdown) V = 0V 1 10 A EN Supply Current (Quiescent) V = 2V, V = 1V 0.9 1.1 mA EN FB Thermal Shutdown 150 C BG Driver Bias Supply Voltage V I = 5mA 4.5 5.0 V CC CC (4) Gate Driver Sink Impedance R 1 SINK (4) Gate Driver Source Impedance R 4 SOURCE Gate Drive Current Sense Trip Threshold V 20 mV SW Note: 4) Guaranteed by design. MP38894 Rev.1.0 www.MonolithicPower.com 2 9/28/2009 MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. 2009 MPS. All Rights Reserved.