NB675 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 NB675 provides a complete power supply 10A Continuous Output Current for DDR3, DDR3L and LPDDR2 memory with 12A Peak Output Current the highest power density. It integrates a high frequency synchronous rectified step-down Built-in +/- 1.5A VTTLDO switch mode converter (VDDQ) with an 1.5A Low R (ON) Internal Power MOSFETs DS sink/source LDO (VTT) and buffered low noise Proprietary Switching Loss Reduction reference (VTTREF). Technique Internal Soft Start The fully integrated Buck converter is able to Output Discharge deliver 10A continuous output current and 12A 500kHZ Switching Frequency peak output current over a wide input supply OCP, OVP, UVP Protection and Thermal range with excellent load and line regulation. Shutdown The Buck converter employs the Constant-On- Latch Off Reset via EN2 or Power Cycle Time (COT) control scheme, which provides fast transient response and eases loop VDDQ Adjustable from 0.604V to 5.5V stabilization. APPLICATIONS The VTT LDO provides 1.5A sink/source Laptop Computer current capability and requires only 10uF Tablet PC ceramic capacitance. Networking Systems The VTTREF tracks VDDQ/2 with an excellent Server 1% accuracy. Personal Video Recorders Flat Panel Television and Monitors Under voltage lockout is internally set as 4.5V. An open drain power good signal indicates Distributed Power Systems VDDQ is within its nominal voltage range. 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. Full protection features include OCP, OVP, and MPS and The Future of Analog IC Technology are registered trademarks of thermal shut down. Monolithic Power Systems, Inc. This part requires minimum number of external components and is available in QFN21 (3mmx4mm) package. TYPICAL APPLICATION 95 85 75 65 55 45 35 25 15 0.001 0.01 0.1 1 10 LOAD CURRENT (A) NB675 Rev. 1.02 www.MonolithicPower.com 1 10/16/2014 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. 2014 MPS. All Rights Reserved. NB675 24V, HIGH CURRENT SYNCHRONOUS BUCK CONVERTER ORDERING INFORMATION Part Number* Package Top Marking NB675GL QFN21 (3mmx4mm) NB675 * For Tape & Reel, add suffix Z (e.g. NB675GLZ) 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 NB675 Rev. 1.02 www.MonolithicPower.com 2 10/16/2014 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. 2014 MPS. All Rights Reserved.