TM
MP18561
3A, 28V, 385KHz
Step-Down Converter
The Future of Analog IC Technology
TM
DESCRIPTION
The MP18561 is a step-down regulator with an
internal Power MOSFET. It achieves 3A
continuous output current over a wide input
supply range with excellent load and line
regulation.
Current mode operation provides fast transient
response and eases loop stabilization.
Fault condition protection includes cycle-by-cycle
current limiting and thermal shutdown. Adjustable
soft-start reduces the stress on the input source
at turn-on. In shutdown mode the regulator draws
2
0μA
of supply current.
The MP18561 requires a minimum number of
readily available external components to
complete a 3A step down DC to DC converter
solution.
FEATURES
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3A Output Current
Programmable Soft-Start
100mΩ Internal Power MOSFET Switch
Stable with Low ESR Output Ceramic
Capacitors
Up to 95% Efficiency
20μA Shutdown Mode
Fixed 385KHz Frequency
Thermal Shutdown
Cycle-by-Cycle Over Current Protection
Wide 4.75V to 28V Operating Input Range
Output Adjustable from 1.22V
Under Voltage Lockout
Available in 8-Pin SOIC Package
Distributed Power Systems
Battery Chargers
Pre-Regulator for Linear Regulators
Flat Panel TVs
Set-Top Boxes
Cigarette Lighter Powered Devices
DVD/PVR Devices
APPLICATIONS
EVALUATION BOARD REFERENCE
Board Number
EV18561DN-00A
Dimensions
2.1”X x 1.3”Y x 0.4”Z
“MPS” and “The Future of Analog IC Technology” are Trademarks of Monolithic
Power Systems, Inc.
TYPICAL APPLICATION
INPUT
4.75V to 28V
2
IN
7
EN
8
1
BS
3
SW
C5
10nF
100
95
Efficiency vs
Load Current
V
IN
= 9V
V
IN
= 24V
V
IN
= 12V
EFFICIENCY (%)
OFF ON
MP1593
SS
GND
4
FB
COMP
6
OUTPUT
3.3V
3A
90
85
80
75
70
65
60
55
50
0
500 1000 1500 2000 2500 3000 3500
5
C6
(optional)
C3
8.2nF
D1
B340A
MP1593_TAC01
LOAD CURRENT (mA)
MP1593_TAC _EC01
MP18561 Rev. 0.1
12/12/2007
www.MonolithicPower.com
MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
© 2007 MPS. All Rights Reserved.
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MPS [ MONOLITHIC POWER SYSTEMS ]
