Why the experimental data do not match the current-voltage characteristics in the datasheet of the diode?

Question

Electronics

I connected in series a laboratory worker with a set voltage of 0.94V to a 1N5399 diode. With a voltage drop across the diode of 0.94V, I received a current of 103mA. These parameters do not agree at all with those stated in the datasheet . Here you can see that at a voltage of 0.9V, the current should be approximately equal to 0.7A

Answer 1

- dubious origin of the diode and / or simply re-marked.
- incorrect measurement points. if the diode was connected by wires to the power supply, and the voltage was set on it until it reached 0.1a == the voltage had to be measured directly at the diode terminals. if the multimeter was connected to the terminals of the power supply, then this is the reason
- the inaccuracy of the multimeter. really only for oldish devices, new ones give fairly accurate data, even from the lowest price category.
- inaccuracy of the multimeter due to a dead battery. infrequent but 101% real option. some multimeters begin to distort the measurements very much even without indication of low voltage supply.
upd. in general, the diode is fully consistent with the docks, for example from diotec:
https://www.tme.eu/Document/32177c6558e4c60ff52a87...

Answer 2

These parameters do not agree at all with those stated in the datasheet.

And they shouldn't. If you looked at the datasheet carefully, you might have noticed there for the parameters not one column, but three - "at least", "typical value" and "no more". This was even more clearly displayed in the old paper reference books that I still remember - they simply drew the entire scatter zone, into which the CVC of a serviceable element should fit. Like this:

Well, everything that did not fit into this zone can be safely declared faulty.

Answer 3

Is the voltage measured across the terminals of the diode? How is the diode connected - soldering or something else? What is the cross section and length of the wires to the diode? Does Lab.BP have 4-wire connectivity? Is it calibrated? Lab.BP implies regulation of both current and voltage - how do you install regulators?

Answer 4

You set the current to 0.7A and look at the drop across the diode, the so-called. Uf. Get what you want.