NB672/NB673 24V, High Current Synchronous Buck Converter With +/-1.5A LDO and Buffed Reference The Future of Analog IC Technology DESCRIPTION FEATURES Wide 5V to 24V Operating Input Range The NB672/NB673 provides a complete power 6A Continuous Output Current and 8A Peak supply for DDR3, DDR3L and LPDDR2 memory Output Current (NB672) with the highest power density. It integrates a 8A Continuous Output Current and 10A high frequency synchronous rectified step-down switch mode converter (VDDQ) with a 1.5A Peak Output Current (NB673) sink/source LDO (VTT) and buffered low noise Built-in +/- 1.5A VTTLDO reference (VTTREF). Low R (ON) Internal Power MOSFETs DS Proprietary Switching Loss Reduction The fully integrated Buck converter of Technique NB672/NB673 is able to deliver 6A/8A Internal Soft Start continuous output current and 8A/10A peak output current over a wide input supply range Output Discharge with excellent load and line regulation. The 500kHZ Switching Frequency Buck converter employs the Constant-On-Time OCP, OVP, UVP Protection and Thermal (COT) control scheme, which provides fast Shutdown transient response and eases loop stabilization. Latch off Reset via EN or Power Cycle. VDDQ Adjustable from 0.604V to 5.5V The VTT LDO provides 1.5A sink/source current capability and requires only 10uF APPLICATIONS ceramic capacitance. Laptop Computer The VTTREF tracks VDDQ/2 with an excellent Tablet PC 1% accuracy. Networking Systems Under voltage lockout is internally set as 4.5V. Server An open drain power good signal indicates Personal Video Recorders VDDQ is within its nominal voltage range. Flat Panel Television and Monitors Full protection features include OCP, OVP, and Distributed Power Systems thermal shut down. All MPS parts are lead-free and adhere to the RoHS directive. For MPS green These two parts require minimum number of status, please visit MPS website under Products, Quality Assurance page. external components and are available in QFN21 MPS and The Future of Analog IC Technology are registered trademarks of (3mmx4mm) package. Monolithic Power Systems, Inc. TYPICAL APPLICATION V 220nF IN VDDQ 5-22V 1.35V VIN BST SW FB EN 1 EN 2 NB672/NB673 PG VDDQSEN VCC VINLDO VTT AGND VTT 0.675V/2A PGND VTTREF VTTSEN 220nF NB672/NB673 Rev. 1.02 www.MonolithicPower.com 1 4/30/2015 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. 2015 MPS. All Rights Reserved. NB672/NB67324V, HIGH CURRENT SYNCHRONOUS BUCK CONVERTER ORDERING INFORMATION Part Number Package Top Marking NB672GL* QFN21 (3mmx4mm) NB672 NB673GL QFN21 (3mmx4mm) NB673 * For Tape & Reel, add suffix Z (e.g. NB672GLZ) PACKAGE REFERENCE TOP VIEW PG NC EN2 VCC EN1 FB 18 17 16 15 14 13 BST 1 VIN 12 19 VIN 2 SW 20 PGND PGND 11 3 SW 21 PGND 10 PGND 9 4586 7 VTTSEN VDDQSEN VTT VTTREF VINLDO AGND EXPOSED PAD ON BACKSIDE (5) (1) Thermal Resistance JA JC ABSOLUTE MAXIMUM RATINGS QFN21 (3mmx4mm) ............... 50 ...... 12 ... C/W Supply Voltage V ....................................... 24V IN V ............................................. -0.3V to 24.3V SW Notes: 1) Exceeding these ratings may damage the device. V (30ns) ........................................ -3V to 28V SW 2) Refer to Page 13 of Configuring the EN Control. V (5ns) .......................................... -6V to 28V SW 3) The maximum allowable power dissipation is a function of the V .................................................. V + 5.5V BST SW maximum junction temperature T(MAX), the junction-to- J ambient thermal resistance , and the ambient temperature JA V .............................................................. 12V EN (2) T . The maximum allowable continuous power dissipation at A Enable Current I ................................ 2.5mA EN any ambient temperature is calculated by P (MAX)=(T (MAX)- D J All Other Pins ............................. 0.3V to +5.5V T )/ . Exceeding the maximum allowable power dissipation A JA (3) will cause excessive die temperature, and the regulator will go Continuous Power Dissipation (T =+25) A into thermal shutdown. Internal thermal shutdown circuitry protects the device from permanent damage. QFN21 ..................................................... 2.5W 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 +150 C (4) Recommended Operating Conditions Supply Voltage V ............................. 5V to 22V IN Output Voltage V ................... 0.604V to 5.5V OUT Enable Current I ...................................... 1mA EN Operating Junction Temp. (T ). -40C to +125C J NB672/NB673 Rev. 1.02 www.MonolithicPower.com 2 4/30/2015 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. 2015 MPS. All Rights Reserved.