Capacitor Labels

Set the capacitor value, and other goodies here. Use the US or the Brit. conventions for the capacitance value. E.g.

2.2u = 2.2u = 2U2 = 2u2 = 2200 = 2.2e-6

Capacitors support temperature co-efficients. These are, TC1 and TC2:

C = Co*(1 + tc1*(Tckt - Tnom) + tc2*(Tckt - Tnom)2 )

Tckt is the operating temperature of the circuit, specified in the main temperature setup dialog or spice options. Tnom is the temperature that the co-efficients of all spice devices are measured also setup in the spice options, and defaults to 27 deg. C.

M Multiplier

The value of resistance used in the actual simulation is the set value of resistance multiplied by its "M" value. "M" is a multiplier.

Example netlist:

C1 1 2 1.2n tc1= 2.5m tc2=1.5u M=4

These values are usually set automatically using the GUI dialog setups.

Semiconductor Capacitors

See the main Spice3 help on semiconductor capacitors for a detailed description. However, SuperSpice has added temperature co-efficients into the basic model, such that:

c1 1 2 semi_cap1 L=12u W= 3.5u
c2 3 4 semi_cap1 L=15u W= 0.5u

.model semi_cap1 c(cj=1m tc1=2.5m tc2=1.5u narrow_l=200n narrow_w=150n cjsw=0.9m)

Cj, is the specific capacity, such that C actual = W*L*Cj, but modified by the above formula for temperature variations. or in complete form:

C = (L - NARROW_L) *(W - NARROW_W) * Cj + 2 * Cjsw(W + L - 2 * (NARROW_L + NARROW_W))

Note that the capacitance displayed is the Cj*W*L simplified value, not the actual value used in the simulation.

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