RT8057A Datasheet, PDF (1/12 Pages) Richtek Technology Corporation – 2.25MHz 1A Synchronous Step-Down Converter

RT8057A
2.25MHz 1A Synchronous Step-Down Converter
General Description
The RT8057A 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 RT8057A 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 RT8057A enters Low Dropout Mode when
normal Pulse -Width Mode cannot provide regulated output
voltage by continuously turning on the upper P-MOSFET.
The RT8057A 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 RT8057A is available in a small WDFN-6SL 2x2
package.
Ordering Information
RT8057A (2)
Pin 1 Orientation
(2) : Quadrant 2, Follow EIA-481-D
(For WDFN-6SL 2x2 Only)
Package Type
QW : WDFN-6SL 2x2 (W-Type)
J5 : TSOT-23-5
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.
Features
z 2.7V to 5.5V Wide Input Operation Range
z 2.25MHz Fixed-Frequency PWM Operation
z Up to 1A Output Current
z Up to 90% Efficiency
z 0.6V Reference Allows Low Output Voltage
z Internal Soft-Start
z No Schottky Diode Required
z Internal Compensation to Reduce External
Components
z Low Dropout Operation : 100% Duty Cycle
z RoHS Compliant and Halogen Free
Applications
z Portable Instruments
z Game Console and Accessories
z Microprocessors and DSP Core Supplies
z Cellular Phones
z Wireless and DSL Modems
z PC Cards
Pin Configurations
(TOP VIEW)
LX 1
NC 2
FB 3
6 GND
5 VIN
7 4 EN
WDFN-6SL 2x2
LX
FB
5
4
2
3
VIN GND EN
TSOT-23-5
Marking Information
For marking information, contact our sales representative
directly or through a Richtek distributor located in your
area.
DS8057A-00 March 2011
www.richtek.com
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