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Why not constant voltage with tiny voltage fluctuation to drive LEDs in series instead of constant current?
There are basically 2 main factors for constant current drive circuit to drive LED’s:\n1. Is to avoid violation of the maximum current rating of the LED and compromising the reliability. LEDs have a wide variation in forward voltages and the forward voltage also changes with the LED current. Additionally, the forward voltage changes with temperature. Therefore the self heating will also change the current \n2. Where luminous intensity and chromaticity from each LED is required.\n\n Please let me know if you have any other questions.
Answered by: ON Semiconductor
2012-01-21 14:18:41.0