Capacitor

In this topic:

Netlist Entry

Cxxxx n1 n2 [model_name] value [IC=initial_condition] [TEMP=local_temp]
[TC1=tc1] [TC2=tc2] [VC1=vc1] [VC2=vc2] [BRANCH=0|1] [M=mult] [DTEMP=dtemp]
[ESR=esr]
 n1 Node 1 n2 Node 2 model_name (Optional) Name of model. Must begin with a letter but can contain any character except whitespace and period '.' value Capacitance (Farads) initial_condition Initial voltage if UIC specified on .TRAN statement. local_temp Capacitor temperature ($°$C) tc1 First order temperature coefficient tc2 Second order temperature coefficient vc1 First order voltage coefficient vc2 Second order voltage coefficient BRANCH May be 0 or 1. 0 is the default. This parameter determines the internal formulation of the capacitor and affects how the IC parameter is implemented. When BRANCH=0, the capacitor looks like an open circuit during the DC operating point and the IC parameter has no effect unless UIC is specified for a transient analysis. If BRANCH=1, the capacitor looks like a voltage source during dc operating point with a magnitude equal to the value of the IC parameter. BRANCH=1 makes it possible to specify circuit startup conditions. See Alternative Initial Condition Implementations for an example. mult Device multiplier. Equivalent to putting mult devices in parallel. dtemp Differential temperature. Similar to local_temp but is specified relative to circuit temperature. If both TEMP and DTEMP are specified, TEMP takes precedence. esr Effective series resistance. If non-zero (the default value), a resistor of value esr will be connected in series with the capacitor. The resulting implementation of a series RC network is more efficient and offers better convergence than using a separate R and C. This is especially the case if the capacitor has a high value and is non-grounded. Important: this resistor is noiseless; if the noise in the ESR is important in your design, you should use a separate resistor and omit this parameter in the capacitor.

Model Syntax

.model modelname CAP ( parameters )

Model Parameters

 Name Description Units Default C Capacitor multiplier 1 TC1 First order temperature coefficient 1/$°$C 0 TC2 Second order temperature coefficient 1/$°$C2 0 VC1 First order voltage coefficient Volt-1 0 VC2 Second order voltage coefficient Volt-2 0 TNOM, T_MEASURED Reference temperature; the temperature at which the model parameters were measured C 27 T_ABS If specified, defines the absolute model temperature overriding the global temperature defined using .TEMP C - T_REL_GLOBAL Offsets global temperature defined using .TEMP. Overridden by T_ABS C 0.0