Diodes AP3019A - Manual

Data Sheet
WHITE LED STEP-UP CONVERTER AP3019A
May. 2010 Rev. 1.8 BCD Semiconductor Manufacturing Limited
1
General Description
The AP3019A is an inductor-based DC/DC converter
designed to drive up to eight white LEDs in series 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
components can be used. Specifically, 1mm tall
inductor and 0.22
µF output capacitor for a typical
application is sufficient. Additionally, the Schottky
diode in boost circuit is integrated on this chip.
AP3019A also provides a disable pin to ease its use
for different systems.
The output over-voltage protection is implemented in
AP3019A. When any LED is broken or in other
abnormal conditions, the output voltage will be
clamped.
The AP3019A is available in standard SOT-23-6 and
TSOT-23-6 packages.
Features
•
Inherently Uniform LED Current
• High Efficiency up to 84%
• No Need for External Schottky Diode
• Output Over-voltage Protection (OVP)
• Fixed 1.2MHz Switching Frequency
• Uses Tiny 1mm Tall Inductor
• Requires Only 0.22
µF Output Capacitor
Applications
• Cellular Phones
• Digital Cameras
• LCD modules
• GPS Receivers
• PDAs, Handheld Computers
Figure 1. Package Types of AP3019A
SOT-23-6 TSOT-23-6