I needed to buy some OA91 diodes, 0.2 low voltage drop for power harvesting project. I guess other diodes are better but I choose these.Off to eBay UK to buy some, got 50 for =A37, they arrived ok. Further checking in eBay list them at =A31.50 EACH, and then 2 for =A3999! Not a typo, and impossible to flag to eBay as an error (i.e. sounds like fraud to me. Check out
Lyn
What about the option to "Report item" opposite the "Postage and payments Tag ??
Rheilly
It says 223 sold and if you click on that link it says everyone paid £0.99 ,so maybe it is a typo.
You can get Schottky diodes with equally low forward voltage drops and lower reverse leakage in smaller and more robust modern packages.
What sort of current do you expect?
A low barrier schottky diode, like something in the SMS7630 family, will be about as good as a germanium at 100 uA and much better at higher currents.
SD103A is a cool part: 200 mV at 1 mA.
I'd expect a power schottky, like a Fairchild SS22, to be pretty good, but you'd have to measure it... the curves don't go to low currents.
John
1-2V reverse bias? Geez, that must be tunneling (zener schottky??). Is there such a thing as a schottky tunnel diode? I'd expect, if you could forward-bias the junction sufficiently, they'd start tunneling. Since schottky junctions use majority carriers that might not be possible though.
Meh, seems like it should still be possible.. after all, you can make negative resistance (N and S type) diodes from oxidized steel and cat whiskers. Must be loads of schottky junctions in something like that.
Tim
It's just a heavily-doped, low barrier schottky. It's spec'd as a microwave detector, but it actually works at 5 or 6 volts reverse.
I don't think so.
People still make "back diodes" as RF detectors. They are germanium tunnel diodes with very low peak point currents, so work as rectifiers in the "wrong" direction, at millivolt levels. They are maybe the only planar germanium semiconductors around, excepting photodiodes.
John
If it can be other Ge diodes you could also just buy NOS. Since you are in Europe I guess purchasing inside the EU is easy and this German outlet has numerous Ge diodes and transistors:
If the link breaks enter this URL
and type "Germanium" into the window below the red "Schnellsuche". I don't know the place but engineers on a German NG buy there a lot. If you need language help let me know.
Can you use synchronous rectification instead?
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