2014-04-05 11:09 GMT+02:00 Vesa Solonen <[email protected]>: > 05/04/14 01:23, Heiko Rosemann kirjoitti: >> On 04/04/2014 10:45 PM, Carl Poirier wrote: >>> I think this is a very good idea. I will add this to our upcoming >>> KiCad library convention. Many transistors use letters already. >> >> I do not agree for footprints, because - at least if I understand >> the proposal correctly - it will lead to many many different >> footprints of the same housing, i.e. an SOT23-EBC, an SOT23-SGD >> (for FETs), an SOT23-CBE, an SOT23-A1-C-A2, an SOT23-A1-C1A2-C2 >> etc. pp. with all the same dimensional data but different pad >> names. > > This is the current state, because of the limited data model. I agree > with you that it's not how it should be. Regarding diodes one can get > _any_ orientation single ones in SOT-23 > >> I came to kicad from Eagle some years ago and I still believe >> distinguishing between symbol-package-device to be the best >> solution for this problem. > > Second that. The implementation inside Kicad is not there yet. The > symbol is somewhat hard linked to the footprint (because symbol have > to contain matching pin numbers) and even the alias system can not > solve the issue.
I never really started to use eagle beacuse of its wierd library. I do like that the symbols are seperate from the footprint in kicad. (Or at leat tries to) > Diode pad names ought to be generated when the component is > instantiated from the symbol, footprint _and_ "device description > data". The device description data is currently embedded in the symbol > and alias system, but that is clearly not working well enough. > > An example: > > SYM: Diode:->|-, pins:2, name:A, name:C > > FP: DO-214AB, pads:2, number:1, number:2, (numbers from JEDEC standard) > > Device 1 > DDD: Device: 5.0SMDJ11-UNI > symbol: Diode > footprint: DO-214AB > pin-pad-mapping: (K,1),(A,2) [no permutations] > manufacturer: Protek Devices > function: Transient voltage suppression 11V > keywords: TVS, zener, diode > data_sheet: > http://www.protekdevices.com/Assets/Documents/Datasheets/5_0smdj.pdf > > Device 2 > DDD: Device: SS3H10 > symbol: Diode > footprint: DO-214AB > pin-pad-mapping: (K,1),(A,2) [no permutations] > manufacturer: Vishay > function: Surface Mount Schottky Rectifier 100V > keywords: schottky, rectifier, diode > data_sheet: http://www.vishay.com/docs/88752/ss3h9.pdf > > > Pin-pad-mapping is expected to contain all gate and pin swap > permutations for devices that allow it, simple devices like > bidirectional TVS zeners and resistors would just have x as a pin name > for interchangeable ones. I have a hard time visualising this workflow. I like the idea of your DDD, but how or where is the pin-pad-mapping defined? Is this defined in a cvpcb-like step? I see that the pin-pad-mapping definition elliminates a bunch of the same symbols ans footprints with each of their all possible pin combinations. >>> As for capacitors, why not also using C and A for cathode and >>> anode? >> >> In my experience, the terminals of a capacitor are not called >> cathode and anode. > > Only polarised (electrolytic) ones will have cathode and anode, but > elsewhere that would be misleading. Rolled foil capacitors used to > have some marking which lead was connected to the outermost electrode, > so one could make the orientation such that the outer electrode and schematic > pins or net data. > protected the other form interference (like capacitance changes from > nearby objects). Precision polystyrene capacitors especially. Lately > I've seen such in modern PTFE ones. > > -Vesa _______________________________________________ Mailing list: https://launchpad.net/~kicad-developers Post to : [email protected] Unsubscribe : https://launchpad.net/~kicad-developers More help : https://help.launchpad.net/ListHelp
