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3.2 Subcircuit and Device Model Definition 211
Plot the diode voltage. In[17]:= TransientPlot[diodedc, V$2[Vin], {Vin, −1., 5.}]
1.5
1
0.5
-1 1 2 3 4 5 Vin
-0.5
V$2[Vin]
-1
Out[17]= Graphics
This example demonstrates how to specify initial conditions. The netlist describes an RLC series
resonator. The behavior of the LC subcircuit is modeled by a system of differential equations.
An RLC circuit with a
behavioral description for
the LC resonator.
Set up time-domain circuit
equations.
Display the circuit
equations.
In[18]:= rlcfilter = Circuit[
Netlist[
{R, {1, 0}, 100.},
{LC, {1 −> "P", 0 −> "N"},
Model −> "LCSeriesResonator",
Selector −> "Behavioral", L −> 0.02, C −> 5.*^−7}
],
Model[
Name −> "LCSeriesResonator",
Selector −> "Behavioral",
Ports −> {"P", "N"}, Parameters −> {L, C},
Variables −> {Current["P", "N"], Voltage["P", "N"],
vind, vcap},
Definition −> Equations[
vind == L*Current["P", "N"]’,
Voltage["P", "N"] − vcap − vind == 0,
Current["P", "N"] == C*vcap’
],
InitialConditions −> {vcap −> 5.,
Current["P", "N"] −> −0.02}
]
]
Out[18]= Circuit
In[19]:= rlcfeqs = CircuitEquations[rlcfilter,
AnalysisMode −> Transient,
InitialConditions −> Automatic]
Out[19]= DAETransient, 6 4
In[20]:= rlcfeqs // DisplayForm
Out[20]//DisplayForm=
I$PN$LCt 0.01 V$1t ⩵⩵ 0, vind$LCt ⩵⩵ 0.02 I$PN$LC ′ t,
vcap$LCt vind$LCt V$1t ⩵⩵ 0, I$PN$LCt ⩵⩵
5. 10 7 vcap$LC ′ t, vcap$LC0 ⩵⩵ 5., I$PN$LC0 ⩵⩵ 0.02,
V$1t, I$PN$LCt, vind$LCt, vcap$LCt, DesignPoint