BAW56 SOT-23 diode alternative?

[slybunda]

hi all, i need a diode which is found here: https://uk.rs-online.com/web/p/switching-diodes/7815161
Its a BAW56 type but its not in stock. Chatting to the webchat people at RS components they said this here is an alternative part: https://uk.rs-online.com/web/p/switching-diodes/7920793
The alternative they suggested is a BAV23A, is this a suitable alternative or does a BAW56 part have to be replaced with another BAW56 part?
thanks

[elektryk]

It depends on application, BAW56 has lower Trr.
BTW it looks like BAW56 is still available (for example in Farnell).

[slybunda]

Yes farnell has it but delivery cost is high. I just need 10 of these. Can get from AliExpress for like £1 for 100pcs but since iv used quality components for everything else i dont want to cheap out right at the end.
I buy from rs components because they are a very short drive away from me so saves on high delivery prices.

[Kleinstein]

There are many variants (e.g. different manufacturers) of the BAW56, and some are still available at RS. There are other types that may be closer (e.g. 1N4148 similar types with 4 ns trr) - here it depends on the application.

Other sources also have them in stock (e.g. TME.EU).

[T3sl4co1l]

I would be shocked if the difference between BAW56 and BAV23A mattered. Maybe it's one of those applications, maybe you can give some context as to whether it would matter, but I would most likely think it doesn't.

Notable differences seem to be V_R, t_rr, C_d (a little bit, but their tolerances easily overlap), and maybe I_FSM (curiously, both provide a plot of this vs. t_p, but onsemi erroneously rates it at 4A (1µs) while plotting 11A!).  It would be weird if V_R is being used as a characteristic (avalanche, but the voltage doesn't matter?*), but again, there's an outside chance it could matter.

*In that they're not rated for it, as zeners are; or avalanche rectifiers for that matter.  So the actual voltage is anyone's guess.  Usually it's 10-40% above V_R, but it could be many times higher as is often the case with rectifiers (I have name-brand 1N4004s that break down ~1.3kV).  They will still avalanche, most likely nondestructively at low currents (DC, thermally limited; pulsed may still be destructive), but the V(I) curve and tempco will be all over the place.  That's generally the case for rectifiers, anyway; I haven't tested a whole lot of small-signal diodes in breakdown.

Tim

[shapirus]

Where's it used in the circuit? It's very likely that there are quite a few possible substitutes.

[slybunda]

used in a solar charge controller probably to power the attiny85 controller chip.
pic attached

[T3sl4co1l]

Yeah, that looks general purpose, literally anything will do.

Tim

[shapirus]

That's a nicely made silk screen!

[slybunda]

That's a nicely made silk screen!

Got it from here: https://github.com/AdamWelchUK/PWM85
bought 2 from the guy, needed 2 more so decided to have a go at making them. fun project.