Diodes AP3019A Manuel d'utilisateur télécharger pdf

Data Sheet

WHITE LED STEP-UP CONVERTER AP3019A

May. 2010 Rev. 1.8 BCD Semiconductor Manufacturing Limited

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 0.22µF 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 0.22µF 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

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