NB673GL-Z

NB672/NB673 24V, High Current Synchronous Buck Converter With +/-1.5A LDO and Buffed Reference The Future of Analog IC Technology DESCRIPTION FEATURES The NB672/NB673 provides a complete power supply for DDR3, DDR3L and LPDDR2 memory with the highest power density. It integrates a high frequency synchronous rectified step-down switch mode converter (VDDQ) with a 1.5A sink/source LDO (VTT) and buffered low noise reference (VTTREF). The fully integrated Buck converter of NB672/NB673 is able to deliver 6A/8A continuous output current and 8A/10A peak output current over a wide input supply range with excellent load and line regulation. The Buck converter employs the Constant-On-Time (COT) control scheme, which provides fast transient response and eases loop stabilization. The VTT LDO provides 1.5A sink/source current capability and requires only 10uF ceramic capacitance. The VTTREF tracks VDDQ/2 with an excellent 1% accuracy. Under voltage lockout is internally set as 4.5V. An open drain power good signal indicates VDDQ is within its nominal voltage range. Full protection features include OCP, OVP, and thermal shut down. These two parts require minimum number of external components and are available in QFN21 (3mmx4mm) package. • • • • • • • • • • • • Wide 5V to 24V Operating Input Range 6A Continuous Output Current and 8A Peak Output Current (NB672) 8A Continuous Output Current and 10A Peak Output Current (NB673) Built-in +/- 1.5A VTTLDO Low RDS(ON) Internal Power MOSFETs Proprietary Switching Loss Reduction Technique Internal Soft Start Output Discharge 500kHZ Switching Frequency OCP, OVP, UVP Protection and Thermal Shutdown Latch off Reset via EN or Power Cycle. VDDQ Adjustable from 0.604V to 5.5V APPLICATIONS • • • • • • • Laptop Computer Tablet PC Networking Systems Server Personal Video Recorders Flat Panel Television and Monitors Distributed Power Systems All MPS parts are lead-free and adhere to the RoHS directive. For MPS green status, please visit MPS website under Products, Quality Assurance page. “MPS” and “The Future of Analog IC Technology” are registered trademarks of Monolithic Power Systems, Inc. TYPICAL APPLICATION 220nF VIN 5-22V VIN BST FB EN 1 EN 2 VDDQ 1.35V SW NB672/NB673 PG VDDQSEN VCC VINLDO VTT AGND PGND VTTREF VTT 0.675V/2A VTTSEN 220nF NB672/NB673 Rev. 1.02 www.MonolithicPower.com 4/30/2015 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2015 MPS. All Rights Reserved. 1 NB672/NB673–24V, HIGH CURRENT SYNCHRONOUS BUCK CONVERTER ORDERING INFORMATION Part Number NB672GL* NB673GL Package QFN21 (3mmx4mm) QFN21 (3mmx4mm) Top Marking NB672 NB673 * For Tape & Reel, add suffix –Z (e.g. NB672GL–Z) PACKAGE REFERENCE TOP VIEW BST SW SW NC EN2 VCC EN1 FB PG 18 17 16 15 14 13 1 19 VIN 20 PGND 21 PGND 12 VIN 11 PGND 10 PGND 2 3 5 4 6 7 8 9 VTTSEN VTT VDDQSEN VTTREF VINLDO AGND EXPOSED PAD ON BACKSIDE (5) ABSOLUTE MAXIMUM RATINGS (1) Thermal Resistance Supply Voltage VIN .......................................24V VSW ............................................. -0.3V to 24.3V VSW (30ns) ........................................ -3V to 28V VSW (5ns) .......................................... -6V to 28V VBST ..................................................VSW + 5.5V VEN ..............................................................12V Enable Current IEN (2)................................ 2.5mA All Other Pins ............................. –0.3V to +5.5V (3) Continuous Power Dissipation (TA=+25°) QFN21 .....................................................2.5W 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) Refer to Page 13 of Configuring the EN Control. 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 θJA θJC QFN21 (3mmx4mm) ............... 50 ...... 12 ... °C/W (4) Supply Voltage VIN ............................. 5V to 22V Output Voltage VOUT................... 0.604V to 5.5V Enable Current IEN ......................................1mA Operating Junction Temp. (TJ). -40°C to +125°C NB672/NB673 Rev. 1.02 www.MonolithicPower.com 4/30/2015 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2015 MPS. All Rights Reserved. 2 NB672/NB673–24V, HIGH CURRENT SYNCHRONOUS BUCK CONVERTER ELECTRICAL CHARACTERISTICS VIN = 12V, TJ = 25°C, unless otherwise noted. Parameters Symbol Condition Min Typ Max Units 0 1 μA 300 400 500 μA 160 190 220 μA Supply Current Supply Current (Shutdown) IIN Supply Current (In S0 Mode) IIN Supply Current (In S3 Mode) IIN VEN = 0V VEN1 = VEN1 =2V, VFB = 0.65V, IVTT = 0A VEN1 = 0V, VEN2 = 2V, VFB = 0.65V MOSFET High-side Switch On Resistance HSRDS-ON Low-side Switch On Resistance LSRDS-ON Switch Leakage SW LKG NB672, TJ =25°C 28 NB673, TJ =25°C 24 NB672, TJ =25°C 10 NB673, TJ =25°C 9 VEN = 0V, VSW = 0V 0 1 μA mΩ mΩ Current Limit Low-side Valley Current Limit NB672 7.5 8.5 9.5 A NB673 8.5 9.5 10.5 A 400 250 500 300 600 350 kHz ns VOVP TOVPDEL VUVP TUVPDEL 125 130 2.5 60 12 135 %VREF μs %VREF μs VREF IFB TSS 598 604 10 1.6 610 50 1.95 mV nA ms 1.15 1.25 100 3 0 1.35 V mV VCCVth 4.5 4.85 VCCHYS 500 ILIMIT Switching frequency and minimum off time Switching frequency (6) Minimum Off Time FS TOFF Over-voltage and Under-voltage Protection OVP Threshold OVP Delay UVP Threshold UVP Delay 55 65 Reference And Soft Start Reference Voltage Feedback Current Soft Start Time VFB = 0.604V Enable And UVLO Enable Input Low Voltage Enable Hysteresis Enable Input Current VCC Under Voltage Lockout Threshold Rising VCC Under Voltage Lockout Threshold Hysteresis VILEN VEN-HYS IEN VEN = 2V VEN = 0V NB672/NB673 Rev. 1.02 www.MonolithicPower.com 4/30/2015 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2015 MPS. All Rights Reserved. μA V mV 3 NB672/NB673–24V, HIGH CURRENT SYNCHRONOUS BUCK CONVERTER ELECTRICAL CHARACTERISTICS (continued) VIN = 12V, TJ = 25°C, unless otherwise noted. Parameters Symbol Condition Min Typ Max Units 4.8 5.1 5.3 V VCC Regulator VCC Regulator VCC VCC Load Regulation Icc=8mA 5 % Power Good FB Rising (Good) PGVth-Hi 95 FB Falling (Fault) PGVth-Lo 85 FB Rising (Fault) PGVth-Hi 115 FB Falling (Good) PGVth-Lo 105 PGTd 450 Power Good Low to High Delay Power Good Sink Current Capability Power Good Leakage Current VPG IPG LEAK %VREF μs Sink 4mA 0.4 V VPG = 3.3V 1 μA VTTREF Output VTTREF Output Voltage VTTREF IVTTREF