Diodes AL8808 User Manual
New prod uc t al8808, Description, Applications
AL8808
Document number: DS35648 Rev. 2 - 2
1 of 20
January 2013
© Diodes Incorporated
NEW PROD
UC
T
AL8808
COST EFFECTIVE LOW EMI 30V 1A BUCK LED DRIVER
Description
The AL8808 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 AL8808 switches at frequency up to
1MHz with controlled rise and fall times to reduce EMI. This allows
the use of small size external components, hence minimizing the PCB
area needed.
Maximum output current of AL8808 is set via an external resistor
connected between the V
IN
and SET input pins. Dimming is achieved
by applying either an analog 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.
Applications
• MR16
Lamps
•
General Illumination Lamps
Pin Assignments
Features
•
LED Driving Current Up to 1A
•
Better Than 5% Accuracy
•
High Efficiency Up to 96%
•
Fast Controlled Falling Edges 7ns
•
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
•
Built-In Over-Temperature Protection
•
TSOT25: Available in “Green” Molding Compound (No Br, Sb)
Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)
Halogen and Antimony Free. “Green” Device (Note 3)
Notes:
1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant.
2. Se information about Diodes Incorporated’s definitions of Halogen and Antimony free, "Green" and Lead-Free.
3. Halogen and Antimony free "Green” products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl)
and <1000ppm antimony compounds.
Typical Applications Circuit
TSOT25
(Top View)
1
2
3
5
4
V
IN
SET
SW
GND
CTRL