What is the Forward Voltage, VF, of an LED? - Learning about …
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The forward voltage of an LED, VF, is the voltage that must be applied across the leads of the LED, from anode to cathode, in order for the LED to turn on.. As you can see above, positive voltage must be applied across the LED from its anode to its cathode. If reversed, this is no longer forward voltage but reverse voltage, and the LED will not light up.
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