RT8009
1.25MHz, 600mA, High Efficiency PWM Step-Down DC/DC
Converter
General Description
Features
ꢀ +2.5V to +5.5V Input Range
The RT8009 is a high-efficiency pulse-width-modulated
(PWM) step-downDC-DC converter. Capable of delivering
600mAoutput current over a wide input voltage range from
2.5 to 5.5V, the RT8009 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.
ꢀ Adjustable Output From 0.5V to VIN
ꢀ 1.0V, 1.2V, 1.5V, 1.8V, 2.5V and 3.3V Fixed/
Adjustable Output Voltage
ꢀ 600mA 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 100% Lead (Pb)-Free
Internal synchronous rectifier with low RDS(ON) dramatically
reduces conduction loss at PWM mode. No external
Schottky diode is required in practical application. The
RT8009 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.
Applications
ꢀ Cellular Telephones
ꢀ Personal InformationAppliances
ꢀ Wireless and DSL Modems
ꢀ MP3 Players
The RT8009 enters Low-Dropout mode when normal PWM
cannot provide regulated output voltage by continuously
turning on the upper P-MOSFET. RT8009 enter shutdown
mode and consumes less than 0.1uAwhen ENpin is pulled
low.
ꢀ Portable Instruments
Ordering Information
RT8009(-
)
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.
Package Type
B : SOT-23-5
J5 : TSOT-23-5
Operating Temperature Range
P : Pb Free with Commercial Standard
G : Green (Halogen Free with Commer-
cial Standard)
Output Voltage
Default : Adjustable
10 : 1.0V
Pin Configurations
12 : 1.2V
15 : 1.5V
18 : 1.8V
(TOP VIEW)
25 : 2.5V
33 : 3.3V
VIN
1
2
3
5
LX
GND
Note :
RichTek Pb-free and Green products are :
`RoHS compliant and compatible with the current require-
ments of IPC/JEDEC J-STD-020.
EN
FB/VOUT
4
SOT-23-5/TSOT-23-5
`Suitable for use in SnPb or Pb-free soldering processes.
`100% matte tin (Sn) plating.
DS8009-03 March 2007
www.richtek.com
1
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
