AL8805 Datasheet, PDF (1/16 Pages) Diodes Incorporated – HIGH EFFICIENCY 30V 1A BUCK LED DRIVER

AL8805
HIGH EFFICIENCY 30V 1A BUCK LED DRIVER
Description
The AL8805 is a step-down DC/DC converter designed to
drive LEDs with a constant current. The device can drive up
to 8 LEDs, depending on the forward voltage of the LEDs, in
series from a voltage source of 6V to 30V. Series connection
of the LEDs provides identical LED currents resulting in
uniform brightness and eliminating the need for ballast
resistors. The AL8805 switches at frequency up to 1MHz.
This allows the use of small size external components, hence
minimizing the PCB area needed.
Maximum output current of AL8805 is set via an external
resistor connected between the V_IN and SET input pins.
Dimming is achieved by applying either a DC voltage or a
PWM signal at the CTRL input pin. An input voltage of 0.4V
or lower at CTRL switches off the output MOSFET simplifying
PWM dimming.
Pin Assignments
(Top View)
SW 1
GND 2
CTRL 3
5 V_IN
4 SET
SOT25
Features
Applications
• LED driving current up to 1A
• Better than 5% accuracy
• MR16 lamps
• High efficiency up to 98%
• General illumination lamps
• Operating input voltage from 6V to 30V
• High switching frequency up to 1MHz
• PWM/DC input for dimming control
• Built-in output open-circuit protection
• SOT25: Available in “Green” Molding Compound (No Br,
Sb) with lead Free Finish/ RoHS Compliant (Note 1)
Notes: 1. EU Directive 2002/95/EC (RoHS). All applicable RoHS exemptions applied. Please visit our website at
http://www.diodes.com/products/lead_free.html.
Typical Application Circuit
AL8805
Document number: DS35030 Rev. 1 - 2
1 of 16
www.diodes.com
September 2010
© Diodes Incorporated