Are these diodes interchangable?

[trashcanman]

I'm collecting parts for a 1176 compressor and the FDH333 diode is hard to come by but I have found an ebay listing for some BAV20s which seem similar, but maybe not close enough.  I believe it's the low reverse current of the FHD333 which is important but looking at the datasheets it hard to figure out how similar they are as they each use different test conditions.
Can anyone tell me if the BAV20 is a suitable replacement?

datasheets:
http://datasheet.octopart.com/FDH333-Fairchild-datasheet-28922.pdf
http://datasheet.octopart.com/BAV20-NXP-Semiconductors-datasheet-11777548.pdf

 

[s2udio]

They are not that rare
http://uk.futureelectronics.com/en/technologies/semiconductors/discretes/diodes/small-signal-diodes/Pages/7612567-FDH333.aspx?gclid=CMKbo92C68wCFaoy0wodQsQCzg

http://eu.mouser.com/ProductDetail/Fairchild-Semiconductor/FDH333/?qs=g8nxp%252b2%252bNK9HiOwI6ZyR5g%3D%3D

http://uk.farnell.com/fairchild-semiconductor/fdh333/diode-low-leakage-do-35/dp/9843760

http://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2055119.m570.l1313.TR0.TRC0.H0.TRS0&_nkw=fdh333&_sacat=0

 

[RuudNL]

I never understood why the FDH333 was so special in this design... 
(IMHO any silicon diode would work, the leak current of any Si diode is many times lower than the discharge resistor(s) in the 1176.)

 

[jsteiger]

Mouser has 24k+ of them

http://www.mouser.com/ProductDetail/Fairchild-Semiconductor/FDH333/?qs=sGAEpiMZZMtoHjESLttvkoBU6cp6%252bZs9dESGLMRRRZ4%3d

 

[gyraf]

BAV20 is 100nA to 10.000nA over 20-100degrees (centigrade)

FD333 is 1nA to 500nA over the same temperature range.

We NEED low leakage because we "float" the FET gate by the Q-bias setting.

Jakob E.

 

[trashcanman]

Alright, I'll get the FDH333 then. I can't find them locally were I live and the shipping from mouser etc. is way too expensive. I have found some cheap ones fleabay though.

 

[RuudNL]

I would first try it with 2 x 1N4148...
Then you know if it works, or not,
Later you could always change the diodes. (Although I doubt if it would make any difference!)

 

[fragletrollet]

edit: wrong thread

 

[JohnRoberts]

In a bind you can make a low leakage diode out of a JFET gate junction... perhaps overkill.

JR