Capacitor Model

Type Name: c

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

Capacitor Model Parameters
name	parameter	units	default	example
m	parallel multiplier	-	1.0	1.2
cj	junction bottom capacitance	F/M2	-	5e-5
cjsw	junction sidewall capacitance	F/M	-	2e-11
defw	default device width	M	1e-6	2e-6
narrow	narrowing due to side etching	M	0.0	1e-7
tnom	parameter measurement temperature	C	25	50
tc1	first order temperature coeff.	$\Omega$/C	0.0	-
tc2	second order temperature coeff.	$\Omega$/C2	0.0	-

The capacitor has a nominal capacitance computed as below, where l and w are parameters from the device line.

C = cj ^. (l- narrow)(w- narrow) + 2cjsw ^. (l+ w- 2 ^. narrow)

After the nominal capacitance is calculated, it is adjusted for temperature by the formula:

C(temp) = C(tnom) ^. (1 + tc1 ^. (temp- tnom) + tc2 ^. (temp- tnom)² )

Finally, the capacitance is multiplied by the parallel multiplication factor (m).