Every diode is different and Vf is usually a function of the diode current. Can you give us more details on your experimental setup and a summary of the results with specific part numbers.Hi.
Most Schottky diodes I have measure around 0.54 Vf. But a couple show 0.18 and 0.19 Vf . Why the difference ?
So I would guess that using the diode setting on the meter provides a constant current and measures the voltage. The only real ambiguity is the value of the constant current source. It should be self evident that a single valued constant current source may have some limitations when it comes to measuring the set of all diodes. It gives you one point on a curve whose shape can vary unexpectedly.Thanks.
All diodes out of circuit, tested with the same vulgar multimeter at -|>|- (diode setting) at same room temperature with no current other than whatever the meter applies.
The ones reading near 0.2Vf are IR0135 31DQ04 and 1N5822
All two dozen more canibalized from equipment, in different flavors show around 0.54Vf. Non-Schottky read around 0.69Vf
I guess the moral of the story is make what measurements you can, but correlate that measurement with the datasheet.Thanks.
Both numbers IR0135 31DQ04 are stamped on a single part. About the same deviation.
----> https://www.mouser.com/catalog/specsheets/9331931d.pdf
I find interesting and convenient that warmer running Schottkys have lower Vf.
A meter with an adjustable diode test current would be handy, but I don't think I have ever seen or heard of such a thing.A diode with a large area will, all else being equal, have a lower forward voltage at a given test current than a diode with a smaller area. This the same for silicon PN, Shottky, germanium, etc.
by Jake Hertz
by Aaron Carman
by Jake Hertz
by Aaron Carman