Posts Tagged ‘led’

Three Things To Note About LED Drivers

February 17th, 2012 No comments
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LEDs operate from DC and are relatively easy to work with but there are three points that help understand regarding the role of an LED driver:

  • Voltage: LEDs in a backlight will be wired in series so in each LED requires 3v and there are 20 LEDs the voltage required will be 60v.
  • Current: The driver will maintain a constant current to the LED’s.
  • Brightness control: Two normal methods to control brightness are by varying the current or using a technique called Pulse Width Modulation (PWM*).

For a display system design perspective the complex work is done by the LED driver design and usage is as straightforward as following the connection specifications.

* PWM creates the impression of lower light by switching the LEDs on/off but at a frequency faster than our perception. Using PWM the brightness can be lower than achievable by simply reducing the current.

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