Hello! I was wondering if there’s any videos where I can watch the process of selecting a particular schottkey diode for a power-related application. I’d like to get some insight into selecting “generic” parts that don’t have interchangeable footprints.
Hi David,
I don’t believe there’s anything like that recorded currently.
I am a little confused by this, as generic parts normally do have interchangeable footprints. I’m going to assume you meant parts that do have interchangeable footprints. If that’s wrong, please let me know below.
Normally for Schottky diodes, I start with a footprint I know and like and then use that as the basis of starting my search. SMA, SMB, SMC footprints are normally what I look for, as they’re standardized and interchangeable ( and they are sized based on how much power they can dissipate (SMA is the highest). So I start with package sizes and then filter for the specifications I need.
Here’s an example search using the packages filtered above:
From there, I would normally look at the forward voltage (at various currents, as spec’d), the power dissipation levels (related to the package), reverse leakage currents and more.
I don’t hear the term generic with respect to electronic components. There are a lot of parts that are second sourced or “cloned”. They tend to have the same footprint and generally behave the same but often have minor differences that may be important.
For example there are many variants of the AMS1117 voltage regulator. They all have the same SOT-223-3 package. Some claim higher current or different heat transfer. The advantage of having many with the same package in this chip shortage era is undeniable.
I would probably look for specific characteristics that you need for your application. If one of the more common parts with second sources works, that’s what I would go for. They tend to be cheaper as well.
Beware that schottky is often not the best search term. You will find many standard diodes that has lower VF at high current than schottky diodes
Also, my two cents, check out the reverse recovery times too, as this can be a factor for efficiency in switch modes.
Thank you, this is very helpful! I didn’t realize there were standard footprints, since starting from Digikey and without practical experience, it’s hard to say whether a package is standard or specialized.
Additionally to everyone else who responded, this is very helpful information, and I’ll be sure to check all those aspects of the parts.
Thank you all!
Get yourself a Digi-Key ruler or similar with popular footprints on them. Consult it regularly. That’ll get you quickly up to speed with a large number of footprints.