AC simulation - LTSpice

[Ingo]

Dear all,

I'm currently working on a interconnect model using resistances,
internal and mutual inductances. For the simulation of frequency
effects, my approach uses simplified skineffect formulas, which of
course take f into account for the calculation. Is there any chance to
get the frequency used by LTSpice during simulation (e.g. using the .AC
command). SwitcherCADIII so far only gives me a warning that it can't
use the frequency using (freq or w).

Any suggestions?

Best regards,

Ingo

 

[Ian]

Dear all,

I'm currently working on a interconnect model using resistances,
internal and mutual inductances. For the simulation of frequency
effects, my approach uses simplified skineffect formulas, which of
course take f into account for the calculation. Is there any chance to
get the frequency used by LTSpice during simulation (e.g. using the .AC
command). SwitcherCADIII so far only gives me a warning that it can't
use the frequency using (freq or w).

Any suggestions?

Best regards,

Ingo

If you look on the CoilCraft site in their models data it shows you how
to do this for PSpice, this approach also works in LTSpice.
http://www.coilcraft.com/models.cfm

Regards
Ian

 

[Ingo]

If you look on the CoilCraft site in their models data it shows you how
to do this for PSpice, this approach also works in LTSpice.
http://www.coilcraft.com/models.cfm

Regards
Ian

Dear Ian,

thanks for the promp reply. However this is what I did in the first
place. It seems like the Freq-command for evaluating the frequency is
only valid in the waveform arithmetics. What I need is the frequency
value when the calculation is carried out. Did you try your method with
parameters that change with frequency?

Regards,

Ingo

 

[Helmut Sennewald]

Dear Ian,

thanks for the promp reply. However this is what I did in the first
place. It seems like the Freq-command for evaluating the frequency is
only valid in the waveform arithmetics. What I need is the frequency
value when the calculation is carried out. Did you try your method with
parameters that change with frequency?

Regards,

Ingo

Hello Ingo,

There is another appnote.
http://www.coilcraft.com/modelspspice.cfm
They use the Laplace operator in the formula which is evaluated
in the simulation. It's exactly what you need.
See also my more exhaustive answer in the LTspice Yahoo group.

Best regards,
Helmut

LTspice/SwitcherCADIII
http://www.linear.com/designtools/softwareRegistration.jsp

User group
http://groups.yahoo.com/group/LTspice/