NB675 Datasheet, PDF (1/21 Pages) Monolithic Power Systems – 24V, High Current Synchronous Buck Converter With 1.5A LDO and Buffed Reference

The Future of Analog IC Technology
NB675
24V, High Current
Synchronous Buck Converter
With +/-1.5A LDO and Buffed Reference
DESCRIPTION
The NB675 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 an 1.5A
sink/source LDO (VTT) and buffered low noise
reference (VTTREF).
The fully integrated Buck converter is able to
deliver 10A continuous output current and 12A
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.
This part requires minimum number of external
components and is available in QFN21
(3mmx4mm) package.
TYPICAL APPLICATION
FEATURES
• Wide 5V to 24V Operating Input Range
• 10A Continuous Output Current
• 12A Peak Output Current
• Built-in +/- 1.5A VTTLDO
• Low R_DS(ON) Internal Power MOSFETs
• Proprietary Switching Loss Reduction
Technique
• Internal Soft Start
• Output Discharge
• 500kHZ Switching Frequency
• OCP, OVP, UVP Protection and Thermal
Shutdown
• 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.
VIN
5-21V
VIN
BST
SW
EN 1
EN 2
PG
VCC
FB
NB675
VDDQSEN
VINLDO
AGND
VTT
PGND VTTREF VTTSEN
220nF
220nF
VDDQ
1.35V/10A
VTT
0.675V/2A
95
85
75
65
55
45
35
25
15
0.001 0.01 0.1
1
10
LOAD CURRENT (A)
NB675 Rev. 1.0
www.MonolithicPower.com
1
1/14/2013
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2013 MPS. All Rights Reserved.