AL5811EV2 User Guide - Diodes Incorporated

AL5811EV2 User Guide
75mA, 60V Low-side Adjustable Linear LED Driver
General Description
The AL5811 is an adjustable Linear LED
driver offering excellent temperature
stability and output handling capability.
The AL5811 simplifies the design of linear
and isolated or non-isolated LED drivers by
setting the LED current with standard value
resistors.
The AL5811 has an open drain output that
can swing from 1V up to 60V enabling it
drive long LED chains. Its low 0.5V RSET pin
is outside of the LED current path and so
accuracy is maintained while minimizing
the required overhead to regulate the LED
current. This reduces its power dissipation
when compared to traditional linear LED
drivers. This makes it ideal for driving LEDs
up to 75mA. Longer LED chains can be
driven by tapping VCC from the chain,
where the chain voltage may exceed 60V.
Specifications
Parameter
Value
Input Voltage
3.5V – 60V (Low Side)
>60V (Floating GND)
75mA (Adjustable)
0.62” x 0.57”
Yes
LED Current
XY Dimension
ROHS Compliance
Top-View EVM (AL5811EV2)
The AL5811EV2 evaluation board provides
U-DFN3030-6 package.
AL5811EV2 (U-DFN3030-6)
Key Features
Connection Instructions



Input Voltage: Red Wire
Ground: Black Wires
LED: White Wire
Low Reference Voltage (VRSET=0.5V)
-40˚C to 125˚C Temperature Range
MSOP-8EP and U-DFN3030-6 packages
Applications




Linear LED Driver
Isolated Offline LED Converters
LED Signs
Instrumentation Illumination
AL5811EV2 Rev2
January 2013
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AL5811EV2 User Guide
75mA, 60V Low-side Adjustable Linear LED Driver
Board Layouts
Note: By default, this evaluation board provides Low side Current LED string configuration in
this user guide document. For design flexibility, multiple application circuits can be derived in
both Low and High Side Current LED configurations with use of PWM dimming.
Evaluation Board Connection Setup and Power-up Procedure
Current LED String Procedure to Evaluation Board in Low side current LED configuration
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January 2013
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AL5811EV2 User Guide
75mA, 60V Low-side Adjustable Linear LED Driver
1.
2.
3.
4.
5.
6.
7.
By default, the evaluation board is preset at 75mA as low side current LED configuration.
Ensure that the DC source is switched OFF or disconnected.
Connect the DC line wires of power supply to VIN and GND terminals on the board.
Connect the anode wire of external LED string to VIN of the board.
Connect the cathode wire of external LED string to LED terminal of the board.
Load 10KΩ to R1 on the board. Do not load any components on R2 and R3.
Ensure that the area around the board is clear and safe, and preferably that the board and
LEDs are enclosed in a transparent safety cover.
8. Turn on the main switch. LED string should light up with LED.
Other Typical Circuit Design Options
I) Current LED String Procedure in High side current LED configuration
1.
2.
3.
4.
5.
6.
7.
8.
9.
The evaluation can be configured as High side current LED configuration.
Ensure that the DC source is switched OFF or disconnected.
Connect the line wire of the DC power supply to VIN and LED terminals on the board.
Connect the GND wire of the DC power supply to GND terminals on the board.
Connect the anode wire of external LED string to floating GND of the board.
Connect the cathode wire of external LED string to earth GND of the DC power supply.
Load 10KΩ to R1 on the board. Do not load any components on R2 and R3.
Observe MAX 60V differential between VIN and floating GND when applied VIN > 60V.
In the high side circuit configuration, extreme high voltage may be present. Please use
caution and try not to touch any components on the board or input leads.
10. Turn on the main switch. LED string should light up with LED.
AL5811EV2 Rev2
January 2013
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AL5811EV2 User Guide
75mA, 60V Low-side Adjustable Linear LED Driver
II) Current LED String Procedure in Low side current LED configuration with PWM dimming
1. The evaluation board can be configured as Low side current LED configuration with use
of PWM dimming.
2. Ensure that the DC source is switched OFF or disconnected.
3. Connect the DC line wires of power supply to VIN and GND terminals on the board.
4. Connect the anode wire of external LED string to VIN of the board.
5. Connect the cathode wire of external LED string to LED terminal of the board.
6. Load 10KΩ to R2 on the board. Do not load any components on R1 and R3.
7. Insert external MOSFET across R3 pads of the board for PWM dimming control.
8. Ensure that the area around the board is clear and safe, and preferably that the board
and LEDs are enclosed in a transparent safety cover.
9. Turn on the main switch. LED string should light up with LED.
AL5811EV2 Rev2
January 2013
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AL5811EV2 User Guide
75mA, 60V Low-side Adjustable Linear LED Driver
Schematic
For AL5811EV2 (U-DFN3030-6)
Bill of Materials
Bill of Material for AL5811EV2 U-DFN3030-6 Evaluation Board (Low Side Current LED String Configuration)
#
1
2
3
4
Name
U1
C1
R1
R2, R3
AL5811EV2 Rev2
January 2013
www.diodes.com
Quantity
1
1
1
0
Part number
AL5811FF
12101C104KAT2A
RR1220P-103-D
N/A
Manufacturer
Diodes Inc
AVX Corp
Susumu
N/A
Description
Adjustable Linear Driver in U-DFN3030-6
CAP CER 0.1µF 100V 10% X7R 1210
RES 10KΩ 1/10W 0.5% 0805 SMD
N/A
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AL5811EV2 User Guide
75mA, 60V Low-side Adjustable Linear LED Driver
Functional Performance
AL5811EV2 Rev2
January 2013
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AL5811EV2 User Guide
75mA, 60V Low-side Adjustable Linear LED Driver
AL5811EV2 Rev2
January 2013
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AL5811EV2 User Guide
75mA, 60V Low-side Adjustable Linear LED Driver
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www.diodes.com
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