RT8025 Datasheet, PDF (1/13 Pages) Richtek Technology Corporation – 1.25MHz, 400mA, High Efficiency PWM Step-Down DC/DC Converter

RT8025
1.25MHz, 400mA, High Efficiency PWM Step-Down
DC/DC Converter
General Description
The RT8025 is a high-efficiency pulse-width-modulated
(PWM) step-down DC/DC converter. Capable of delivering
400mA output current over a wide input voltage range from
2.5 to 5.5V, the RT8025 is ideally suited for portable
electronic devices that are powered from 1-cell Li-ion
battery or from other power sources within the range such
as cellular phones, PDAs and handy-terminals.
Internal synchronous rectifier with low R_DS(ON) dramatically
reduces conduction loss at PWM mode. No external
Schottky diode is required in practical application. The
RT8025 automatically turns off the synchronous rectifier
while the inductor current is low and enters discontinuous
PWM mode. This can increase efficiency at light load
condition.
The RT8025 enters Low-Dropout mode when normal PWM
cannot provide regulated output voltage by continuously
turning on the upper P-MOSFET. RT8025 enter shutdown
mode and consumes less than 0.1μA when EN pin is pulled
low.
The switching ripple is easily smoothed-out by small
package filtering elements due to a fixed operation
frequency of 1.25MHz. This along with small SOT-23-5
and TSOT-23-5 package provides small PCB area
application. Other features include soft start, lower internal
reference voltage with 2% accuracy, over temperature
protection, and over current protection.
Pin Configurations
(TOP VIEW)
LX FB/VOUT
5
4
2
3
VIN GND EN
SOT-23-5/TSOT-23-5
Features
2.5V to 5.5V Input Range
Adjustable Output From 0.5V to V_IN
1.0V, 1.2V, 1.3V, 1.5V, 1.8V, 2.5V and 3.3V Fixed/
Adjustable Output Voltage
400mA Output Current
95% Efficiency
No Schottky Diode Required
1.25MHz Fixed Frequency PWM Operation
Small SOT-23-5 and TSOT-23-5 Package
RoHS Compliant and Halogen Free
Applications
Cellular Telephones
Personal Information Appliances
Wireless and DSL Modems
MP3 Players
Portable Instruments
Ordering Information
RT8025(- )
Package Type
B : SOT-23-5
J5 : TSOT-23-5
Lead Plating System
G : Green (Halogen Free and Pb Free)
Note :
Output Voltage
Default : Adjustable
10 : 1.0V
12 : 1.2V
13 : 1.3V
15 : 1.5V
18 : 1.8V
25 : 2.5V
33 : 3.3V
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.
Marking Information
For marking information, contact our sales representative
directly or through a Richtek distributor located in your
area.
DS8025-02 March 2011
www.richtek.com
1