High Efficiency PWM Step-Down DC-DC Converter
The RT9201 is a high-efficiency pulse-width-modulated
(PWM) step-down DC-DC converter. Capable of delivering
600mA output current over a wide input voltage range
from 2.5 to 5.5V, the RT9201 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.
Four operational modes are available: PWM, PSM, Low-
Dropout and shut-down modes. Internal synchronous
rectifier with low RDS(ON) dramatically reduces conduction
loss at PWM mode. No external Schottky diode is
required in practical application. The RT9201 auto-
matically 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 RT9201 enters PSM (pulse-skipping mode) at
extremely light load condition. The equivalent switching
frequency is reduced to increase the efficiency in PSM.
The RT9201 enters Low-Dropout mode when normal
PWM cannot provide regulated output voltage by
continuously turning on the upper P-MOSFET. RT9201
enters shut-down 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 800kHz. This along with small VDFN package
provides small PCB area application. Other features
include soft start, 0.8V internal reference voltage with
1% accuracy, over temperature protection, and over
For marking information, contact our sales representative
directly or through a RichTek distributor located in your
area, otherwise visit our website for detail.
DS9201-11 March 2007
l +2.5V to +5.5V Input Range
l Adjustable Output From 0.85V to VIN
l 600mA Output Current
l 95% Efficiency
l No Schottky Diode Required
l 85µA Quiescent Current
l 100% Duty Cycle in Low-Dropout Mode
l 800kHz Fixed-Frequency PWM Operation
l Pulse-skipping Mode Operation During Light Ioad
l RoHS Compliant and 100% Lead (Pb)-Free
l Cellular Telephones
l Wireless Modems
l Personal Information Appliances
l Portable Instruments
l Distributed Power Systems
l Battery-Powered Equipment
(1 Li-Ion or 3 NiMH/NiCd)
QV : VDFN-10L 3x3 (V-Type)
Operating Temperature Range
P : Pb Free with Commercial Standard
G : Green (Halogen Free with Commer-
RichTek Pb-free and Green 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.
}100% matte tin (Sn) plating.