Incorporating Spice model to LTSPICE ?

[guitar89]

I have done sucessfully using ONSEMI .lib on transistors, but now I try zener diode i want to do, I couldn't sucess in many attempts. (looks hazy)
I wanted to get BZX85C20, but couldn't found, if anyone could provide me then i would be happy.
Because I couldn't find it, I find other 20V zener diode to put it, but I need get error or no different (the rail voltage is still 25V instead of 20V). So I think I messed up the model or so while implement, hoping someone could point out my mistake.

MY example would be this :
http://www.onsemi.com/pub_link/Collateral/1N5932BRL.LIB
It seems have multiple models there, and neither of them could work. (for my simulation)
Could anyone test and tell me how to incorporate them ?

 

[dchisholm]

Refer to example shown in atch files.

Also see files at
< http://tech.groups.yahoo.com/group/LTspice/files/ Lib/Z-Diodes from ONSEMI/ >
and discussion at
< Yahoo! Groups >
< Yahoo! Groups >

Dale

 

[guitar89]

how to incorporate into library ? (discrete.dio) Would like to learn that.

 

[dchisholm]

That ON Semiconductor subcircuit-type model can not be incorporated into the LTSpice "standard.dio" library.

I have been told that the intrinsic SPICE diode model (listed as "dxxx anode_node cathode_node type_model" in the SPICE netlist) does not accurately model the Zener breakover behavior. (I don't have a reference handy to support that statement.) As a result, many SPICE models for Zener diodes use subcircuit models containing several components instead of the intrinsic SPICE diode model. One article that discusses this is "Spice Subcircuit Accurately Models Zener Characteristics" at < http://www.ema-eda.com/products/other/articles/Zener.pdf >. You can find more information about creating SPICE models for Zener diodes, both using the intrinsic diode model as well as subcircuit models, by seeding a search engine with "zener diode spice model".

Dale