®
RT8251
5A, 24V, 570kHz Step-Down Converter
General Description
The RT8251 is a monolithic step-down switch mode
converter with a built-in internal power MOSFET. It achieves
5A 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.
The RT8251 provides protection functions such as
cycle-by-cycle current limiting and thermal shutdown. In
shutdown mode, the regulator draws 25μA of supply
current. Programmable soft-start minimizes the inrush
supply current and the output overshoot at initial startup.
The RT8251 requires a minimum number of external
components. The RT8251 is available in WQFN-16L 3x3
and SOP-8 (Exposed Pad) packages.
Features
Wide Operating Input Voltage Range : 4.75V to 24V
Adjustable Output Voltage Range : 0.8V to 15V
Output Current up to 5A
25μA Low Shutdown Current
μ
Internal Power MOSFET : 70mΩ
Ω
High Efficiency up to 95%
570kHz Fixed Switching Frequency
Stable with Low ESR Output Ceramic Capacitors
Thermal Shutdown Protection
Cycle-By-Cycle Over Current Protection
RoHS Compliant and Halogen Free
Applications
Distributed Power Systems
Battery Charger
DSL Modems
Pre-regulator for Linear Regulators
Pin Configurations
(TOP VIEW)
VIN
VIN
SW
SW
16 15 14 13
Ordering Information
12
VIN
VIN
VIN
GND
1
2
3
4
5
6
7
8
SW
RT8251
Package Type
QW : WQFN-16L 3x3 (W-Type)
SP : SOP-8 (Exposed Pad-Option 1)
Lead Plating System
G : Green (Halogen Free and Pb Free)
Note :
Richtek products are :
RoHS compliant and compatible with the current require-
ments of IPC/JEDEC J-STD-020.
Suitable for use in SnPb or Pb-free soldering processes.
GND
17
SW
10
SW
9
BOOT
11
WQFN-16L 3x3
BOOT
VIN
SW
GND
2
3
4
8
7
FB
COMP
EN
SS
SS
EN
COMP
FB
GND
9
6
5
SOP-8 (Exposed Pad)
Copyright
©
2013 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
DS8251-04 February 2013
www.richtek.com
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RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
