Capacitor

CXXXXXXX N+ N- VALUE <IC=INCOND>

Examples:

CBYP 13 0 1UF
COSC 17 23 10U IC=3V
CL OUT 0 CLOAD C=10p

N+ and N- are the positive and negative element nodes, respectively. VALUE is the capacitance in Farads.

For the capacitor, the (optional) initial condition is the initial (time-zero) value of capacitor voltage (in volts). Note that the initial conditions (if any) apply only if the UIC option is specified on the .TRAN statement.

Capacitor Model

Examples:

.MODEL CFLT CAP (C=1.5 DEV 10% TC1=.02 TC2=.0045)

Capacitor Model Parameters-

Semiconductor Capacitors

CXXXXXXX N1 N2 <VALUE> <MNAME> <L=LENGTH> <W=WIDTH>+ <IC=VAL>

Examples:

CLOAD 2 10 10P

CMOD 3 7 CMODEL L=10u W=1u 

This is the more general form of the capacitor presented earlier, and allows for the calculation of the actual capacitance value from strictly geometric information and the specifications of the process. If VALUE is specified, it defines the capacitance. If MNAME is specified, then the capacitance is calculated from the process information in the model MNAME and the given LENGTH and WIDTH. If VALUE is not specified, then MNAME and LENGTH must be specified. If WIDTH is not specified, then it will be taken from the default width given in the model. Either VALUE or MNAME, LENGTH, and WIDTH may be specified, but not both sets.

Semiconductor Capacitor Model

The semiconductor capacitor model contains process information that may be used to compute the capacitance from strictly geometric information.

Semiconductor Capacitor Model Parameters-

The capacitor has a capacitance computed as:

CAP = CJ * ( LENGTH - NARROW ) * ( WIDTH - NARROW ) + 2 * CJSW 
+ * ( LENGTH + WIDTH - 2 * NARROW )

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