AP5726

WHITE LED STEP-UP CONVERTER

AP5726 Rev. 1

1 of 16

JUNE 2009

www.diodes.com

•

Inherently Matched LED Current

•

High Efficiency: 84% Typical

•

Fast 1.2MHz Switching Frequency

•

Current limit and UVLO Protections

•

Internal Thermal Shutdown

•

Internal Over Voltage Protection

•

Integrated Soft-start Function

•

SOT26 and DFN2020C-6: Available in “Green”

Molding Compound (No Br, Sb)

•

Lead Free Finish/RoHS Compliant (Note 1)

The AP5726 is a step-up DC/DC converter specifically designed

to drive white LEDs with a constant current. The device can drive

2~6 LEDs in series from a Li-Ion cell. Series connection of the

LEDs provides identical LED currents resulting in uniform

brightness and eliminates the need for ballast resistors. The

AP5726 switches at 1.2MHz that allows the use of tiny external

components. A low 0.31V feedback voltage minimizes power loss

in the current setting resistor for better efficiency.

•

Cellular Phones

•

PDAs, Hand help Computers

•

Digital Cameras

•

MP3 Players

•

GPS Receivers

Typical Application Circuit

V

IN

SW

EN

GND

FB

AP5726

C

OUT

1uF

15

L1

22uH

D1

V

IN

C

IN

1uF

OVP

2~6 LEDs

PWM Dimming

OFF

ON

Figure 1. Typical Application Circuit

Features

General Description

Applications