Diodes AL8807 User Manual
Al8807, Description, Features
AL8807
Document number: DS35281 Rev. 5 - 2
1 of 20
March 2013
© Diodes Incorporated
AL8807
HIGH EFFICIENCY LOW 36V 1A BUCK LED DRIVER
Description
The AL8807 is a step-down DC/DC converter designed to drive LEDs
with a constant current. The device can drive up to 9 LEDs,
depending on the forward voltage of the LEDs, in series from a
voltage source of 6V to 36V. Series connection of the LEDs provides
identical LED currents resulting in uniform brightness and eliminating
the need for ballast resistors. The AL8807 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 AL8807 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.
Features
LED Driving Current up to 1.3A (MSOP-8EP)
Better Than 5% Accuracy
High Efficiency up to 96%
Optimally Controlled Switching Speeds
Operating Input Voltage from 6V to 36V
PWM/DC Input for Dimming Control
Built-In Output Open-Circuit Protection
SOT25, MSOP-8EP: 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)
Pin Assignments
SOT25
(Top View)
SW
GND
CTRL
SET
V
IN
(Top View)
MSOP-8EP
SET
GND
GND
CTRL
V
IN
N/C
SW
SW
Applications
MR16
Lamps
General Illumination Lamps
12V Powered LED Lamps
24V Powered LED Lamps
Notes:
1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant.
2. S more 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
100 nF
C 1
1µF
C 4
D1
DFLS 2100
D2
DFLS 2100
D3
DFLS 2100
D 5
DFLS 2100
D 4
DFLS 2100
GND
SW
GND
CTRL
SE
T
V
IN
U 1
AL8807
0 R15
R1
L 1
33µH
100nF
C5
150µF
C 2
150µF
C3
P1
P 2
ANODE
CATHODE