RT8057
2.25MHz 1A Synchronous Step-Down Converter
General Description
The RT8057 is a high efficiency Pulse-Width-Modulated
(PWM) step-down DC/DC converter, capable of delivering
1A output current over a wide input voltage range from 2.7V
to 5.5V. The RT8057 is ideally suited for portable electronic
devices that are powered from 1-cell Li-ion battery or from
other power sources such as cellular phones, PDAs, hand-
held devices, game console and related accessories.
The internal synchronous rectifier with low R
DS(ON)
dramatically reduces conduction loss at PWM mode.
No external Schottky diode is required in practical
applications. The RT8057 enters Low Dropout Mode when
normal Pulse -Width Mode cannot provide regulated output
voltage by continuously turning on the upper P-MOSFET.
The RT8057 enters shut-down mode and consumes less
than 1μA when
the EN pin is pulled low. The switching
ripple is easily smoothed-out
by small package filtering
elements due to a fixed operating frequency of 2.25MHz.
The RT8057 is available in a small WDFN-6SL 2x2 package.
Features
2.7V to 5.5V Wide Input Operation Range
2.25MHz Fixed-Frequency PWM Operation
Up to 1A Output Current
Up to 90% Efficiency
0.6V Reference Allows Low Output Voltage
Internal Soft-Start
No Schottky Diode Required
Internal Compensation to Reduce External
Components
Low Dropout Operation : 100% Duty Cycle
RoHS Compliant and Halogen Free
Applications
Portable Instruments
Game Console and Accessories
Microprocessors and DSP Core Supplies
Cellular Phones
Wireless and DSL Modems
PC Cards
Ordering Information
RT8057
(2)
Taping Type ( Pin1 at Q2)
Package Type
QW : WDFN-6SL 2x2 (W-Type)
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.
Pin Configurations
(TOP VIEW)
GND
LX
NC
FB
1
2
3
6
5
4
GND
VIN
EN
7
WDFN-6SL 2x2
Marking Information
J7 : Product Code
J7W
W : Date Code
DS8057-03
November 2011
www.richtek.com
1
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
