On a diode datsheet, is the value quoted as the forward voltage the same as the cut-in voltage?
Yes, well kinda...
The model of the diode suddenly becoming conductive at a given voltage is a simplification. It begins to carry small currents the instant it has any forward voltage, and the current increases as an exponential function of voltage until its resistance and ability to generate carriers kicks in.
I always look at the curve based on expected operating current and temperature then find the typical voltage drop.
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