®
RT7257C
3A, 18V, 340kHz Synchronous Step-Down Converter
General Description
Features
z
1.5% High Accuracy Reference Voltage
The RT7257C is a high efficiency, monolithic synchronous
step-down DC/DC converter that can deliver up to 3A
output current from a 4.5V to 18V input supply. The
RT7257C's current mode architecture and external
compensation allow the transient response to be
optimized over a wide input voltage range and loads.
Cycle-by-cycle current limit provides protection against
shorted outputs, and soft-start eliminates input current
surge during start-up. The RT7257C also provides under
voltage protection and thermal shutdown protection. The
low current (<3μA) shutdown mode provides output
disconnection, enabling easy power management in
battery-powered systems. The RT7257C is available in
an SOP-8 (Exposed Pad) package.
z 4.5V to 18V Input Voltage Range
z 3A Output Current
z Integrated N-MOSFET Switches
z Current Mode Control
z Fixed Frequency Operation : 340kHz
z Output Adjustable from 0.8V to 15V
z Stable with Low ESR Ceramic Output Capacitors
z Up to 95% Efficiency
z Programmable Soft-Start
z Cycle-by-Cycle Over Current Protection
z Input Under Voltage Lockout
z Output Under Voltage Protection
z Thermal Shutdown Protection
z RoHS Compliant and Halogen Free
Ordering Information
RT7257C
Applications
z Wireless AP/Router
Package Type
SP : SOP-8 (Exposed Pad-Option 2)
z Set-Top-Box
z Industrial and Commercial Low Power Systems
z LCDMonitors and TVs
Lead Plating System
Z : ECO (Ecological Element with
Halogen Free and Pb free)
z Green Electronics/Appliances
z Point of Load Regulation of High-PerformanceDSPs
H : UVP Hiccup
L : UVP Latch-Off
Pin Configurations
Note :
Richtek products are :
(TOP VIEW)
` 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.
8
BOOT
VIN
SS
2
3
4
7
6
5
EN
GND
SW
COMP
FB
9
GND
Marking Information
SOP-8 (Exposed Pad)
RT7257CxZSP : Product Number
RT7257Cx
ZSPYMDNN
x : H or L
YMDNN : Date Code
Copyright 2012 Richtek Technology Corporation. All rights reserved.
©
is a registered trademark of Richtek Technology Corporation.
DS7257C-02 September 2012
www.richtek.com
1
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
