Data Sheet
WHITE LED STEP-UP CONVERTER
General Description
The AP3009 is an inductor-based DC/DC converter
designed to drive up to six white LEDs in series for
backlight. Only one feedback resistor is needed to con-
trol the LED current and obtain satisfied brightness.
A constant frequency 1.2MHz PWM control scheme is
employed in this IC, which means the tiny external
components can be used. In fact, 1mm tall inductor and
0.22
µ
F output capacitor for the typical application is
very appropriate. Additionally, the schottky diode in
boost circuit is integrated in this chip. AP3009 also
provide a disable port to ease its use for different sys-
tems.
The over output voltage protection is equipped in
AP3009. When any LED is broken or in other abnor-
mal conditions, the output voltage will be clamped to
30V.
The AP3009 is available in standard SOT-23-6 pack-
age.
AP3009
Features
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Inherently Uniform LED Current
High Efficiency: 83% Typical
No Need for Extra Schottky Diode
Over Output Voltage Protection
Drives 2 to 6 LEDs
Fast 1.2MHz Switching Frequency
Uses Tiny 1mm Tall Inductor
Requires Only 0.22
µ
F Output Capacitor
Applications
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Cellular Phones
Digital Cameras
LCD modules
GPS Receivers
PDAs, Handheld Computers
SOT-23-6
Figure 1. Package Type of AP3009
Apr. 2007 Rev. 1. 4
1
BCD Semiconductor Manufacturing Limited
BCDSEMI [ BCD SEMICONDUCTOR MANUFACTURING LIMITED ]
