NB634EL-LF-Z Datasheet, PDF (1/13 Pages) MPS Industries, Inc. – High Efficiency 5A, 24V, 500kHz Synchronous Step-down Converter

The Future of Analog IC Technology
DESCRIPTION
The NB634 is a high efficiency synchronous
rectified step-down switch mode converter with
built-in internal power MOSFETs. It offers a
very compact solution to achieve 5A continuous
output current over a wide input supply range
with excellent load and line regulation. The
NB634 operates at high efficiency over a wide
output current load range.
Current mode operation provides fast transient
response and eases loop stabilization.
Full protection features include latch-off OCP and
thermal shut down.
The NB634 requires a minimum number of
readily available standard external components
and is available in a space saving QFN14 (3mm x
4mm) package.
NB634
High Efficiency 5A, 24V, 500kHz
Synchronous Step-down Converter
FEATURES
 Wide 4.5V to 24V Operating Input Range
 5A Output Current
 Low R_DS(ON) Internal Power MOSFETs
 Proprietary Switching Loss Reduction
Technique
 Fixed 500kHz Switching Frequency
 Sync from 300kHz to 2MHz External Clock
 Internal Compensation
 Latch-off OCP Protection and Thermal
Shutdown
 Output Adjustable from 0.8V
 Available in a QFN14 (3mmx4mm) Package
APPLICATIONS
 Notebook Systems and I/O Power
 Networking Systems
 Digital Set Top Boxes
 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 （FOR NOTEBOOK）
4.5V-24V
VIN
VCC
C1
22uF
R3
R4
ON/OFF
1 _IN
3.3V
9
PG
10 _AAM
11
C3
VCC
0.1uF
NB634
7 _{EN/SY NC}
BST ⁶
SW ^2,3,4,5
C4
0.1uF
L1
2.3uH
8
FB
Rt
24.9k
GND
12,13,14
R1
10k
R2
8.06k
C2
47uF
VOUT 1.8V
Efficiency
V_OUT=1.8V, L=1.0uH
100
95
VIN=7V
90
VIN=12V
85
80
VIN=24V
75
70
65
60
55
50
0123456
OUTPUT CURRENT (A)
NB634 Rev. 0.94
www.MonolithicPower.com
1
12/25/2013
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