Data Sheet
WHITE LED STEP-UP CONVERTER
General Description
The AP3029 is an inductor-based DC/DC converter
designed to drive up to six white LEDs in series or 2
rows of LEDs with 5 for each in parallel for backlight.
Only one feedback resistor is needed to control the
LED current and obtain required brightness.
A constant frequency 1.2MHz PWM control scheme is
employed in this IC, which means tiny external com-
ponents can be used. In fact, 1mm tall inductor and
0.22
µ
F output capacitor for a typical application is suf-
ficient. Additionally, the schottky diode in boost circuit
is integrated on this chip. AP3029 also provides a dis-
able pin to ease its use for different systems.
The over output voltage protection is equipped in
AP3029. When any LED is broken or in other abnor-
mal conditions, the output voltage will be clamped.
The AP3029 is available in standard SOT-23-6 and
TSOT-23-6 packages.
AP3029
Features
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·
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Inherently Uniform LED Current
High Efficiency up to 83.5%
No Need for External Schottky Diode
Over Output Voltage Protection
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
TSOT-23-6
Figure 1. Package Types of AP3029
Oct. 2009 Rev. 1. 8
1
BCD Semiconductor Manufacturing Limited
BCDSEMI [ BCD SEMICONDUCTOR MANUFACTURING LIMITED ]
