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2.10 Nonlinear Symbolic Approximation 171
In[5]:= Plot3D[ivloadPSpice[VLOAD, II],
{VLOAD, 0., 3.5}, {II, 0., 0.001},
AxesLabel −> {"VLOAD", "II", ""},
PlotLabel −> "IVLOAD (PSpice)"]
IVLOAD (PSpice)
0.0003
0.0002
0.0001
0
1
VLOAD
2
3
0
0.001
0.0008
0.0006
0.0004
II
0.0002
Out[5]= SurfaceGraphics
Equation Setup
In the next step the equation system has to be set up. For this we import the PSpice .cir-file and
convert it into an Analog Insydes Circuit object using the command ReadNetlist (Section 3.10.1).
In[6]:= netlist = ReadNetlist[
"AnalogInsydes/DemoFiles/Sqrt.cir",
Simulator −> "PSpice"];
DisplayForm[netlist]
Out[7]//DisplayForm=
Circuit:
Netlist Raw, 8 Entries:
Q1, 3 C, 5 B, 0 E, Model ModelBJT, BJTNPN, Q1, Selector Selec
Q2, 1 C, 3 B, 5 E, Model ModelBJT, BJTNPN, Q2, Selector Selec
Q3, OUT C, 3 B, 4 E, Model ModelBJT, BJTNPN, Q3, Selector Sel
Q4, 4 C, 4 B, 0 E, Model ModelBJT, BJTNPN, Q4, Selector Selec
VLOAD, 1, OUT, Type VoltageSource, Value AC 0, DC Transient 3.
II, 5, 0, Type CurrentSource, Value AC 0, DC Transient 0.0001
IB, 1, 3, Type CurrentSource, Value AC 0, DC Transient 0.0001
VDC, 1, 0, Type VoltageSource, Value AC 0, DC Transient 5., S
ModelParametersName BJTNPN, Type NPN
GlobalParametersSimulator PSpice
Afterwards, we set up a symbolic DC equation system using the modified nodal formulation. Since
we are not interested in temperature effects, we instruct CircuitEquations (Section 3.5.1) to replace
TEMP, TNOM, the elementary charge $q, and Boltzmann’s constant $k by their numerical values.