NB638 High Efficiency, Fast Transient, 7A, 28V Synchronous Step-down Converter in a Tiny 3x4mm QFN Package DESCRIPTION FEATURES The NB638 is a fully integrated, high frequency Wide 4.5V to 28V Operating Input Range synchronous rectified step-down switch mode 7A Output Current converter. It offers a very compact solution to Internal 30m High-Side, 12m Low-Side achieve 7A continuous output current over a Power MOSFETs wide input supply range with excellent load and Proprietary Switching Loss Reduction line regulation. The NB638 operates at high Technique efficiency over a wide output current load range. 1% Reference Voltage Programmable Soft Start Time Constant-On-Time (COT) control mode Soft Shutdown provides fast transient response and eases loop stabilization. 200kHz to 1MHz Switching Frequency SCP, OCP, OVP, UVP Protection and Full protection features include SCP, OCP, OVP, Thermal Shutdown UVP and thermal shutdown. Output Adjustable from 0.8V to 14V The NB638 requires a minimum number of Available in a QFN20 (3x4mm) Package readily available standard external components APPLICATIONS and is available in a space-saving QFN20 (3x4mm) package. Notebook Systems and I/O Power Networking Systems Optical Communication Systems Distributed Power and POL Systems All MPS parts are lead-free, halogen-free, and adhere to the RoHS directive. For MPS green status, please visit the MPS website under Quality Assurance. MPS and The Future of Analog IC Technology are registered trademarks of Monolithic Power Systems, Inc. TYPICAL APPLICATION NB638 Rev.1.19 www.MonolithicPower.com 1 10/26/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. 2017 MPS. All Rights Reserved. NB638HIGH EFFICIENCY, FAST TRANSIENT SYNCHRONOUS STEP-DOWN CONVERTER ORDERING INFORMATION Part Number* Package Top Marking NB638DL QFN-20 (3mmx4mm) NB638 * For Tape & Reel, add suffix Z (e.g. NB638DLZ) For RoHS compliant packaging, add suffix LF (e.g. NB638DLLFZ) PACKAGE REFERENCE (5) (1) Thermal Resistance JA JC ABSOLUTE MAXIMUM RATINGS QFN-20 (3mm x4mm) .............. 48 ...... 10 ... C/W Supply Voltage V ....................................... 30V IN V ....................................... -0.3V to V + 0.3V SW IN Notes: V (30ns) ...................................-3V to V + 3V 1) Exceeding these ratings may damage the device. SW IN 2) Guaranteed by design. V .....................................................V + 6V BST SW 3) The maximum allowable power dissipation is a function of the I ....................................................... 3.5A VIN (RMS) maximum junction temperature T (MAX), the junction-to- J ambient thermal resistance , and the ambient temperature JA V .................................... -0.3V to V +0.6V PGOOD CC (2) T . The maximum allowable continuous power dissipation at A V ........................................... -0.3V to 12V FREQ any ambient temperature is calculated by P (MAX)=(T (MAX)- D J All Other Pins ................................. -0.3V to +6V T )/ . Exceeding the maximum allowable power dissipation A JA (3) will cause excessive die temperature, and the regulator will go Continuous Power Dissipation (T = +25C) A into thermal shutdown. Internal thermal shutdown circuitry .2.6W protects the device from permanent damage. 4) The device is not guaranteed to function outside of its Junction Temperature .............................. 150C operating conditions. Lead Temperature ................................... 260C 5) Measured on JESD51-7, 4-layer PCB. Storage Temperature ............... -65C to +150C (4) Recommended Operating Conditions Supply Voltage V .......................... 4.5V to 28V IN Output Voltage V ........................ 0.8V to 14V OUT Maximum Junct. Temp (T ) ...... -40C to +125C J NB638 Rev.1.19 www.MonolithicPower.com 2 10/26/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. 2017 MPS. All Rights Reserved.