AL8861Q
HIGH EFFICIENCY 40V 1.5A
AUTOMOTIVE GRADE BUCK LED DRIVER
Description
Pin Assignments
The AL8861Q is a hysteresis mode DC-DC step-down LED driver,
designed for driving single or multiple series of the connected LEDs
efficiently from a voltage source higher than the LED voltage. The
device can operate with an input supply from 4.5V to 40V and provide
an externally adjustable output current up to 1.5A for the MSOP-8EP
package. Depending upon supply voltage and external components,
this converter can provide up to 40W of output power.
MSOP-8EP
ISENSE
GND
1
2
3
4
8
VIN
N/C
LX
7
6
EP
GND
The AL8861Q integrates the power switch and a high-side output
current sensing circuit, which uses an external resistor to set the
nominal average output current.
VSET
5
LX
Top View
Dimming can be realized by applying an external control signal to the
VSET pin. The VSET pin will accept either a DC voltage signal or a
PWM (pulse-width modulation) signal.
Applications
Automotive interior LED lamps
Automotive exterior LED lamps
The soft-start time can be adjusted by an external capacitor from the
VSET pin to the ground. Applying a voltage of 0.2V or lower to the
VSET pin can turn off the output and make the device enter into
standby state with low power consumption.
The AL8861Q is qualified to AEC-Q100 Grade 1 and is automotive
grade to support PPAPs.
Features
Wide Input-Voltage Range: 4.5V to 40V
Output Current Up to 1.5A
Internal 40V NDMOS Switch
Typical 5% Output Current Accuracy
Single Pin for On/Off and Brightness Control by DC Voltage or
PWM Signal
High Efficiency (> 95%)
LED Short-Circuit Protection
Inherent Open-Circuit LED Protection
Sense Resistor Short-Circuit Protection
Overtemperature Shutdown
Up to 1MHz Switching Frequency
Pb-Free MSOP-8EP Package
Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)
Halogen and Antimony Free. “Green” Device (Note 3)
The AL8861Q is suitable for automotive applications
requiring specific change control; this part is AEC-Q100
qualified, PPAP capable, and manufactured in IATF16949
certified facilities.
https://www.diodes.com/quality/product-definitions/
Notes:
1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS), 2011/65/EU (RoHS 2) & 2015/863/EU (RoHS 3) compliant.
2. See https://www.diodes.com/quality/lead-free/ 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.
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www.diodes.com
July 2023
AL8861Q
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Document number: DS41798 Rev. 4 - 2