®
RT7257G
3A, 18V, 800kHz Synchronous Step-Down Converter
General Description
The RT7257G 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
RT7257G'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 RT7257G 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 RT7257G is available in
an SOP-8 (Exposed Pad) package.
Features
±
1.5% High Accuracy Reference Voltage
4.5V to 18V Input Voltage Range
3A Output Current
Integrated N-MOSFET Switches
Current Mode Control
Fixed Frequency Operation : 800kHz
Output Adjustable from 0.8V to 12V
Up to 95% Efficiency
Programmable Soft-Start
Stable with Low ESR Ceramic Output Capacitors
Cycle-by-Cycle Current Limit
Input Under Voltage Lockout
Output Under Voltage Protection
Thermal Shutdown Protection
RoHS Compliant and Halogen Free
Marking Information
RT7257GxZSP : Product Number
Applications
Wireless AP/Router
Set-Top-Box
Industrial and Commercial Low Power Systems
LCD Monitors and TVs
Green Electronics/Appliances
Point of Load Regulation of High-Performance DSPs
RT7257Gx
ZSPYMDNN
x : H or L
YMDNN : Date Code
Simplified Application Circuit
V
IN
C
IN
R
EN
VIN
BOOT
RT7257G
SW
EN
SS
C
SS
GND
COMP
FB
C
C
R
C
R2
R1
C
OUT
C
BOOT
L
V
OUT
Copyright
©
2012 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
DS7257G-01
September 2012
www.richtek.com
1
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
