AL5802

30V, ADJUSTABLE CURRENT SINK LINEAR LED DRIVER

AL5802

Document number: DS35516 Rev.4 - 2

1 of 11

www.diodes.com

November 2011

© Diodes Incorporated

Description

The AL5802 combines a high gain NPN transistor with a pre-

biased NPN transistor to make a simple small footprint LED

driver.

The LED current is set by an external resistor connected to

from REXT pin (6) to GND pin (4), the internal high gain

transistor develops approximately 0.6V across the external

resistor.

The AL5802 open-collector output can operate from 0.8V to

30V enabling it to operate from 5V to 24V power supplies

without additional components.

PWM dimming of the LED current can be achieved by either

driving the BIAS pin (2) with a low impedance voltage

source, or driving the EN pin (3) with an external open-

collector NPN transistor or open-drain N-channel MOSFET.

The AL5802 is available in a SOT26 package and is ideal for

driving 20mA to 120mA LED currents.

Pin Assignments

(Top View)

SOT26

Features

•

•

-40 to 125ºC temperature range

•

0.8V to 30V open-collector output

•

Negative temperature co-efficient – automatically reduce the LED

current at high temperatures

•

Low thermal impedance SOT26 with copper leadframe

•

SOT26: Available in “Green” Molding Compound (No Br, Sb)

•

Qualified to AEC-Q101 Standards for High Reliability

Applications

•

Linear LED driver

•

LED signs

•

Offline LED luminaries

Typical Application Circuit

654

123

Q2

Q1