Electronics > Projects, Designs, and Technical Stuff
Trouble finding non-schottky SMD power diode
MustardMan:
Hi All,
I am having great difficulty finding a surface mount (preferably SMC package) power diode that is not schottky. I have a specialised application that requires the voltage drop present across a silicon PN junction (ie: 0.7 volts), but it seems that pretty much every manufacturer has gone schottky because of the lower Vf.
Does anyone have any pointers to non-shottky power diodes, preferably with a curve similar to the '2017 S10AL' diode shown below? I require 10 Amps. Even a leaded device would be fine!
Two images:
The 2017 datasheet for the S10AL (from digikey) shows a curve suggesting that the knee is close to 0.7 volts.
The 2019 datasheet from the manufacturers website shows that the knee is likely to dip under 0.6 volts (at 100mA it is already under 0.7 volts, wheras the "old" one was way above).
Cheer, MM.
exe:
Put two schottky diodes in series? Also, what is the average current?
However, I advice giving us more details. May be the problem can be solved elsehow. I'm also a bit skeptical that the drop should be exactly 0.6-0.7V as it largely varies with the temperature. So, please tell us why a regular 10A
PS it seems the original device is still possible to buy: https://octopart.com/search?q=S10AL¤cy=USD&specs=0 .
PPS current rating of 10A for such a small part is indeed very uncommon.
TheUnnamedNewbie:
trusting something on the knee voltage of a single junction seems like a bad idea, since it is so temperature and current dependent. I think it would help to look at why you (think) you need it to work that way and then see if there isn't a better way around it.
OM222O:
look up idea diode, basically fets as diodes.
Couple it with some sort of op amp and a normal fet to generate the 0.7V with the help of a low value resistor.
I wouldn't trust just a normal diode for this application.
magic:
There are reasonable reasons to avoid Schottky's besides desiring the voltage drop. For example, their reverse leakage is terrible.
--- Quote from: MustardMan on August 19, 2020, 12:18:33 pm ---I require 10 Amps. Even a leaded device would be fine!
--- End quote ---
Ahem, that's 7W of power dissipation. No surprise it's hard to find SMD parts, but I'm sure there are many options in TO-220 :P
Perhaps you could use some MOSFET's body diode? A diode-strapped power BJT? Such parts would be available in DPAK and similar packages, not sure if it's good enough for 7W.
Navigation
[0] Message Index
[#] Next page
Go to full version