RT9271 Datasheet, PDF (1/5 Pages) Richtek Technology Corporation – White LED Step-Up Converter in Tiny Package

Product specification
RT9271
General Description
The RT9271 is a step-up DC/DC converter specifically
designed to drive white LEDs with a constant current. The
device can drive one to three LEDs in series from a Li-Ion
cell. Series connection of the LEDs provides identical LED
currents resulting in uniform brightness and eliminating
the need for ballast resistors. The RT9271 switches at 1.1
MHz, allowing the use of tiny external components. The
input and output capacitor can be as small as 1uF, saving
space and cost versus alternative solutions. A low 0.25V
feedback voltage minimizes power loss in the current
setting resistor for better efficiency.
The RT9271 is available in low profile SOT-23-6 package.
Ordering Information
RT9271
Package Type
B : SOT-23-5
E : SOT-23-6
Operating Temperature Range
P : Pb Free with Commercial Standard
G : Green (Halogen Free with Commer-
cial Standard)
Marking Information
For marking information, contact our sales representative
directly or through a RichTek distributor located in your
area, otherwise visit our website for detail.
Features
z Inherently Matched LED Current
z Up to 80mA Output Current @ V_OUT < 12V
z High Efficiency : 85% Typical
z Drives Up to Three LEDs from 2.8V Supply
z 20V Internal Switch
z Fast 1.1 MHz Switching Frequency
z Uses Tiny 1 mm Height Inductors
z Requires Only 1uF Output Capacitor
z Low Profile SOT-23-6 Package
z Optional 15V Over Voltage Protection
z RoHS Compliant and 100% Lead (Pb)-Free
Applications
z Mobile Phone
z Digital Still Camera
z PDAs, Handheld Computers
z MP3 Players
z GPS Receivers
Pin Configurations
(TOP VIEW)
VCC
EN
5
4
12 3
LX GND FB
SOT-23-5
VCC OVP EN
65 4
123
LX GND FB
SOT-23-6
Note : There is no pin1 indicator on top mark for SOT-23-6
type, and pin1 will be lower left pin when reading top mark
from left to right.
http://www.twtysemi.com
[e-mail]
4008-318-123
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