NB638DL-LF-P

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 synchronous rectified step-down switch mode converter. It offers a very compact solution to achieve 7A continuous output current over a wide input supply range with excellent load and line regulation. The NB638 operates at high efficiency over a wide output current load range.    Constant-On-Time (COT) control mode provides fast transient response and eases loop stabilization. Full protection features include SCP, OCP, OVP, UVP and thermal shutdown. The NB638 requires a minimum number of readily available standard external components and is available in a space-saving QFN20 (3x4mm) package.         Wide 4.5V to 28V Operating Input Range 7A Output Current Internal 30mΩ High-Side, 12mΩ Low-Side Power MOSFETs Proprietary Switching Loss Reduction Technique 1% Reference Voltage Programmable Soft Start Time Soft Shutdown 200kHz to 1MHz Switching Frequency SCP, OCP, OVP, UVP Protection and Thermal Shutdown Output Adjustable from 0.8V to 14V Available in a QFN20 (3x4mm) Package APPLICATIONS     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 10/26/2017 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 1 NB638–HIGH 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. NB638DL–Z) For RoHS compliant packaging, add suffix –LF (e.g. NB638DL–LF–Z) PACKAGE REFERENCE (5) θJA θJC ABSOLUTE MAXIMUM RATINGS (1) Thermal Resistance Supply Voltage VIN .......................................30V VSW ....................................... -0.3V to VIN + 0.3V VSW (30ns)...................................-3V to VIN + 3V VBST .....................................................VSW + 6V IVIN (RMS) .......................................................3.5A VPGOOD....................................-0.3V to VCC+0.6V VFREQ ........................................... -0.3V to 12V(2) All Other Pins ................................. -0.3V to +6V Continuous Power Dissipation (TA = +25°C) (3) ………………………………… …………….2.6W Junction Temperature .............................. 150C Lead Temperature ................................... 260C Storage Temperature ............... -65C to +150C Notes: 1) Exceeding these ratings may damage the device. 2) Guaranteed by design. 3) The maximum allowable power dissipation is a function of the maximum junction temperature TJ(MAX), the junction-toambient thermal resistance θJA, and the ambient temperature TA. The maximum allowable continuous power dissipation at any ambient temperature is calculated by PD(MAX)=(TJ(MAX)TA)/θJA. Exceeding the maximum allowable power dissipation will cause excessive die temperature, and the regulator will go into thermal shutdown. Internal thermal shutdown circuitry protects the device from permanent damage. 4) The device is not guaranteed to function outside of its operating conditions. 5) Measured on JESD51-7, 4-layer PCB. Recommended Operating Conditions QFN-20 (3mm x4mm) .............. 48 ...... 10 ... C/W (4) Supply Voltage VIN .......................... 4.5V to 28V Output Voltage VOUT........................ 0.8V to 14V Maximum Junct. Temp (TJ) ...... -40C to +125C NB638 Rev.1.19 10/26/2017 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 2 NB638–HIGH EFFICIENCY, FAST TRANSIENT SYNCHRONOUS STEP-DOWN CONVERTER ELECTRICAL CHARACTERISTICS VIN = 12V, TA = +25C, unless otherwise noted. Parameters Symbol Supply Current (Shutdown) IIN Supply Current (Quiescent) IIN (5) HS Switch On Resistance (5) LS Switch On Resistance Switch Leakage Current Limit ILIMIT One-Shot On Time TON (5) OCP hold-off time (5) Feedback Voltage Feedback Current Soft Start Charging Current Soft Stop Charging Current Power Good Rising Threshold Power Good Falling Threshold Power Good Rising delay Power Good Rising delay Power Good Rising delay EN Rising Threshold EN Threshold Hysteresis EN Input Current VIN Under-Voltage Lockout Threshold Rising VIN Under-Voltage Lockout Threshold Hysteresis VCC Regulator VCC Load Regulation Min VEN = 0V VEN = 2V VFB = 1V HSRDS-ON LSRDS-ON SW LKG Minimum Off Time (5) Fold-back Off Time Condition VEN = 0V VSW = 0V or 12V ILIM=1(HIGH) TOC ILIM=1(HIGH) VFB 500 μA 30 12 mΩ mΩ 10 A 250 ns 100 1.4 ns μs 40 TA=25C 823 0C