I slightly modified a MOSFET symbol with correct diode type and pinout, for a IRL640A logic level MOSFET. They aren’t the highest tech MOSFET as far as Rds, but they are logic-level and moderately priced.
I think that the “wings” indicate avalanche protection for the MOSFET. I do not know if the physics comparison to a zener diode is rigorous, but the earliest MOSFETs could be easily destroyed by modest drain-source overvoltage breakdown current. The manufacturers introduced avalanche protection which at least sort of seems like a zener diode. So I think it is intended to be meaningful.
Do you like deeper meaning in your electronic component symbols? Tell a story while in a submarine that is 200 meters down… No wait…I think it would be better to just read a dictionary while down in the submarine.
I thought about that, and my research showed some manufacturers have wings and some not, and I decided whether winged or not, it is in the transistor case, I cannot change the diode, so any old diode symbol will do and if I need to know more, consult the data sheet.
@BrendaEM
Hi, there are eight different versions of this symbol… all the pin / terminal combinations. These are all compliant with the Kicad Library Convention found here under libraries; something else you probably haven’t stumbled across yet.
Thanks for the share.
I read your other thread.
A lot of the problems causing you frustration, I think, is a lack of good, current, in depth, documentation.
There is a great beginners guide here, but this only really gets you upto the start line. There is also some stuff in the FAQ, and there should be a lot more soon.
[Respectfully…coming from someone who once professionally wrote documentation and had a youtube user-interface suggestion video that 31,000 views and 663 likes, the Library, Footprint, and Symbol UI needs some work.]
These are the eight symbols I mentioned above.
The symbol you required has the cyan arrow. The GDS means pin1 = G, pin2 = D, pin3 = S
The one immediately above is: 1 = D, 2 = S, 3 = G
The fifth one down is: 1 = G, 2 = S, 3 = D
This convention is consistent throughout the official Kicad libraries.
There are a lot of MOSFETs which are packaged in SOIC-8 as well as some partially layout compatible packages. But IRL640 is in TO220 so is not one of them.
Does this help to answer your question? I am really not sure. No kidding this time…
I guess like everything else, the symbols are not so well standardized. I see that the IRL640 claims to be avalanche protected but the symbol appears to be a non-zener symbol. So whomever wrote the datasheet had not “gotten the memo.”
I’ve stopped reading posts from bob. Signal to noise ratio is too low and I need to preserve my own sanity, and writing responses only further derails threads.
Well yes. Of course we have all seen bad datasheets. In this case, the datasheet clearly states that the MOSFET is avalanche protected. I am not sure that the non zener type diode constitutes an error. At least at face value, I do not see a lot of harm from this.
Brenda SFAIK that is your first mention of an “8-pin device.” (I did not install or look at your KiCad symbol. I use my own symbols; I would have to delete it after viewing it in KiCad) So your mention of 8 pins in your sentence which I quoted seems like a “right turn” in your line of questions. Are you:
Looking for an 8 pin MOSFET?
Looking for an 8 pin MOSFET symbol?
It seems that you are not getting your concerns addressed but it is not clear what you are asking for?
FWIW it depends upon preferences and manufacturing considerations (as well as the footprint you use) but I usually use a 3 pin symbol (and 3 pin footprint) even for 8 pin MOSFETs if I will be building the board.