Guest
I am trying to model a current clamp in Spice based on a mathematical
model which uses frequency dependent inductances.
I have seen various articles on using Laplace code blocks for
frequency dependent expressions, but these don't seem to behave
properly when in circuit for AC sweeps,
and I have tried passing parameters to the inductor value but these
only seem to work in AC or Transient not both.
What I am hoping to achieve is an inductor whose inductance is
selected from a look up table based on the instantaneous frequency of
the stimulating waveform.
I have included an example netlist below to show the solution I am
trying to get working.
NB I am using ICAP4 which insists on Laplace functions being
denominator loaded hence the use of "1/s" rather than just "s" to
extract the frequency.
V1 1 0 AC=1
L1 1 2 (v(5))
R1 2 0 1k
B1 103 0 V=v(1)
A1 103 104 LAPLACEA1
..MODEL LAPLACEA1 s_xfer( in_offset=0 gain=1 num_coeff=[0 1]
den_coeff=[1 0] denorm_freq=1)
A2 104 105 TABLEA2
..MODEL TABLEA2 Pwl( xy_array=[<< Table of F v L >>] input_domain=.01
fraction=true)
R2 105 0 1
..END
When I run the above sort of circuit in AC mode it seems to calculate
L at the start of the run and keep it constant.
I need a model that will work in both AC and TRAN as the intention is
to replicate results from a network analyser to validate the circuit
model against an actual device and then perform TRAN runs to examine
the time domain response under varying conditions.
model which uses frequency dependent inductances.
I have seen various articles on using Laplace code blocks for
frequency dependent expressions, but these don't seem to behave
properly when in circuit for AC sweeps,
and I have tried passing parameters to the inductor value but these
only seem to work in AC or Transient not both.
What I am hoping to achieve is an inductor whose inductance is
selected from a look up table based on the instantaneous frequency of
the stimulating waveform.
I have included an example netlist below to show the solution I am
trying to get working.
NB I am using ICAP4 which insists on Laplace functions being
denominator loaded hence the use of "1/s" rather than just "s" to
extract the frequency.
V1 1 0 AC=1
L1 1 2 (v(5))
R1 2 0 1k
B1 103 0 V=v(1)
A1 103 104 LAPLACEA1
..MODEL LAPLACEA1 s_xfer( in_offset=0 gain=1 num_coeff=[0 1]
den_coeff=[1 0] denorm_freq=1)
A2 104 105 TABLEA2
..MODEL TABLEA2 Pwl( xy_array=[<< Table of F v L >>] input_domain=.01
fraction=true)
R2 105 0 1
..END
When I run the above sort of circuit in AC mode it seems to calculate
L at the start of the run and keep it constant.
I need a model that will work in both AC and TRAN as the intention is
to replicate results from a network analyser to validate the circuit
model against an actual device and then perform TRAN runs to examine
the time domain response under varying conditions.
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