Cut Sheet

Driver output
Suitable applications
Pulse width
modulation
(PWM)
•
Fixtures that must be dimmed very low and still maintain consistent color
•
Color mixing applications that require precise levels for each color
•
Most commonly used driver output
Constant
current reduction
(CCR)
•
Fixtures requiring a UL Class 2 rated output with an output voltage higher than
the UL Class 2 PWM voltage level
•
Applications where long wire runs may exist between the driver and the light
engines and high performance dimming is required
•
Applications that have strict EMI requirements, such as medical suites
•
Applications with high motion activity or rotating machinery
For more information, please use the following resources:
•
LED Driver Selection Tool (www.lutron.com/LEDBuildAModel)
•
Lutron LED Control Center of Excellence (1-877-DIM-LED8 or email [e-mail])
•
Controlling LEDs whitepaper P/N 367-2035 REV B
Details for building a Lutron LED driver modelnumber
1
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Choosing an LED dimming method
For constant current LED drivers, there are two mechanisms for dimming: pulse width modulation (PWM)
and constant current reduction (CCR). Constant voltage LED drivers always use PWM. In a PWM driver,
the current is switched at a high frequency between zero and the rated output current. The ratio of on
time to off time determines the perceived light level. In a CCR supply, the current flows continuously at a
set amount to achieve a given light level.
Certain applications may favor a particular dimming method for best results. In most cases, either
approach is suitable.
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Details for building a Lutron® LED driver modelnumber
Typical applications
Details
Constant
current
•
Down light or sconce
•
One light source per driver (much like a fluorescent
lamp with its associated ballast)
•
For a pre-made LED array designed to operate at
or below a set current level
Constant
voltage
•
Cove, under-cabinet light
or an area with a variable
number of fixtures
•
For one or more LED arrays connected in parallel
•
Similar to electronic or magnetic low-voltage power
supplies that often have 12 V and 24 V outputs
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Choosing an LED driver output
Lutron LED drivers offer models for both constant current and constant voltage applications. These two
types of drivers are not interchangeable, and the design of the LED array, decided upon by the fixture
manufacturer, determines which driver is appropriate.
The driver’s output is determined by the design of the fixture’s LED array, and must therefore be selected
by the fixture manufacturer.
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For more information, please use the following resources:
•
LED Driver Selection Tool (www.lutron.com/LEDBuildAModel)
•
Lutron LED Control Center of Excellence (1-877-DIM-LED8 or email [e-mail])
Ballasts and drivers | Ballasts and drivers |
66 | Lutron Lutron | 67
LED driver model numbers LED driver model numbers