The Designer's Guide Community Forum
https://designers-guide.org/forum/YaBB.pl Simulators >> Circuit Simulators >> PSPICE mosfet model help! https://designers-guide.org/forum/YaBB.pl?num=1262609052 Message started by saqib S on Jan 4th, 2010, 4:44am |
Title: PSPICE mosfet model help! Post by saqib S on Jan 4th, 2010, 4:44am hi everyone, i needed some help with MOSFET simulation in orcad capture.I`m trying to simulate a geometric mean circuit using MOSFETS in capture. I downloaded a BSIM v3 .lib file from somewhere and converted it to a .olb file. The problem is that whenever i use an NMOS from this library,it runs jus fine but whenever i try to use a PMOS trans., pspice displays an error on simulation "Missing Model"...can anyone help me with this? I make sure that i add the .lib file to the design b4 simulation. i have attached the .lib file as well as the NETLIST generated in both cases **NETLIST FOR PMOS*** * source TEST V_V5 N247842 0 1Vdc M_Q1 N247893 N247842 0 M12L3P V_V4 N247893 0 2Vdc R_R1 N247893 N250324 1k V_V3 N250324 0 -5Vdc **NETLIST FOR NMOS** * source TEST V_V5 N247842 0 1Vdc M_Q2 N247893 N247842 0 0 M12L3N V_V4 N247893 0 2Vdc R_R1 N247893 N250324 1k V_V3 N250324 0 -5Vdc As can be seen from the netlist,PSPICE genrates 4 nodes for NMOS but only 3 for PMOS...i tried looking for a 4th pin in the model but cant find it anyhwre...ANY IDEAS? |
Title: Re: PSPICE mosfet model help! Post by Geoffrey_Coram on Jan 4th, 2010, 6:37am I have a vague memory that in Orcad capture there are a couple different PMOS symbols; maybe you chose a 3-terminal symbol, and hopefully if you look you can find a 4-terminal symbol (one that netlists with 4 terminals). An alternative might be to define your own 3-terminal subckt and connect the 4th terminal to some global net. |
Title: Re: PSPICE mosfet model help! Post by saqib S on Jan 4th, 2010, 8:50am well you see, i didnt choose the symbol myself...i created the MOSFET from the library i had downloaded...so it isnt upto me how many pins i define.. is there some place i could find a level 3 or level 7 MOSFET part having 4 terminals? |
Title: Re: PSPICE mosfet model help! Post by Geoffrey_Coram on Jan 4th, 2010, 1:05pm Since the .lib file you attached doesn't specify the number of pins, I don't understand why you think the number of pins isn't up to you. Perhaps you should read the documentation for whatever you used to convert .lib to .olb, or maybe this will give you a hint: http://www.orcad.com/forums/ShowPost.aspx?PostID=7487 |
The Designer's Guide Community Forum » Powered by YaBB 2.2.2! YaBB © 2000-2008. All Rights Reserved. |