MP1570
3A, 23V, 340KHz Synchronous Rectified
Step-Down Converter
MP1570 Rev. 1.5 www.MonolithicPower.com 1
1/31/2006 MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
© 2006 MPS. All Rights Reserved.
The Future of Analog IC Technology
TM
TM
DESCRIPTION
The MP1570 is a monolithic synchronous buck
regulator. The device integrates 100mΩ
MOSFETS that provide 3A continuous load
current over a wide operating input voltage of
4.75V to 23V. Current mode control provides
fast transient response and cycle-by-cycle
current limit.
An adjustable soft-start prevents inrush current
at turn-on. In shutdown mode, the output is
actively discharged by transferring energy in the
output capacitor to the input capacitor, dropping
the supply current to 1µA.
This device, available in an 8-pin SOIC
package, provides a very compact system
solution with minimal reliance on external
components.
EVALUATION BOARD REFERENCE
Board Number Dimensions
EV1570DN-00A 2.0”X x 1.5”Y x 0.5”Z
FEATURES
• 3A Output Current
• Wide 4.75V to 23V Operating Input Range
• Integrated 100mΩ Power MOSFET Switches
• Output Adjustable from 1.23V to 20V
• Up to 95% Efficiency
• Programmable Soft-Start
• Stable with Low ESR Ceramic Output Capacitors
• Fixed 340KHz Frequency
• Cycle-by-Cycle Over Current Protection
• Input Under Voltage Lockout
• Thermally Enhanced 8-Pin SOIC Package
APPLICATIONS
• Distributed Power Systems
• Pre-Regulator for Linear Regulators
• Notebook Computers
“MPS” and “The Future of Analog IC Technology” are Trademarks of Monolithic
Power Systems, Inc.
TYPICAL APPLICATION
INPUT
4.75V to 23V
OUTPUT
3.3V
3A
C3
3.3nF
D1
B130
(optional)
C5
10nF
MP1570
BSIN
12
3
5
64
8
7
FB
SW
SS
GND COMP
EN
C6
(optional)
MP1570_TAC01
100
95
90
85
80
75
70
65
60
EFFICIENCY (%)
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
LOAD CURRENT (A)
MP1570-EC02
Efficiency vs.
Load Current
V
IN
=9V
V
IN
=12V
V
IN
=23V
V
OUT
=5V
