AL8807A Datasheet, PDF (1/20 Pages) Diodes Incorporated – HIGH EFFICIENCY LOW EMI WIDE ANALOG DIMMING RANGE 36V 1A/1.3A BUCK LED DRIVER

Description
The AL8807A is a step-down DC/DC converter designed to drive
LEDs with a constant current. The device can drive up to 9 white high
brightness LEDs in series from a voltage source of 6V to 36V.
The AL8807A has an extended CTRL pin voltage range; increasing
its analog dimming range to greater than 10:1. The improved analog
dimming range makes it suitable for a variety of lighting applications
requiring wide analog dimming ranges.
The AL8807A 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 AL8807A is set via an external resistor
connected between the V_IN and SET input pins.
Over Temperature Protection is incorporated so that should a fault
occur the device will automatically shut-down and only restart when
its junction temperature has cooled down,
Features
• LED Driving Current up to 1A/1.3A
• Better than 5% Accuracy
• High Efficiency Up to 96%
• Optimally Controlled Switching Speeds
• Operating Input Voltage from 6V to 36V
• Wide Analog Input Range for Dimming Control (>10:1)
• Built-in Protection Features:
ƒ Open-Circuit LED protection
ƒ LED Chain Short Circuited
ƒ Over-Temperature Protection
• MSOP-8EP and SOT25: Available in “Green” Molding Compound
(No Br, Sb) with lead Free Finish/ RoHS Compliant
ƒ Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)
ƒ Halogen and Antimony Free. “Green” Device (Note 3)
AL8807A
HIGH EFFICIENCY LOW EMI WIDE ANALOG
DIMMING RANGE 36V 1A/1.3A BUCK LED DRIVER
Pin Assignments
(Top View)
SW 1
GND 2
5 V_IN
CTRL 3
4 SET
SOT25
(Top View)
SET 1
GND 2
GND 3
CTRL 4
8 V_IN
7 N/C
6 SW
5 SW
MSOP-8EP
Applications
•
General Illumination Lamps
•
12V Powered LED Lamps
•
Wide Analog Dimming Range LED Lamps
Notes:
1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant.
2. See http://www.diodes.com for 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
D1 ^R1
V_IN:
6 ~ 36V
C1
V_IN
SET
AL8807A
Analog Dimming
Input:
CTRL GND SW
C2
L1
AL8807A
Document number: DS35990 Rev. 1 - 2
1 of 20
www.diodes.com
September 2012
© Diodes Incorporated