Resistors

- General Form:
`r`*name**n1 n2*[*value*|*modname*] [*options*] [r=*expr*|`poly`*c0*[*c1*...]]

*Options*: [m=*mult*] [temp=*temp*] [tc1=*tcoeff1*] [tc2=*tcoeff2*] [l=*length*] [w=*width*]

[noise=*mult*]

- Examples:
`rload 2 10 10k`

rmod 3 7 rmodel l=10u w=1u

The *n1* and *n2* are the two element nodes, and *value*
is the resistance, for a constant value resistor. A resistor model
*modname* can alternatively be specified and allows the
calculation of the actual resistance value from strictly geometric
information and the specifications of the process. If a resistance is
specified after *modname*, it overrides the geometric information
(if any) and defines the nominal-temperature resistance. If *modname* is specified, then the resistance may be calculated from the
process information in the model *modname* and the given *length* and *width*. In any case, the resulting value will be
adjusted for the operating temperature *temp* if that is
specified, using correction factors given. If *value* is not
specified, then *modname* and *length* must be specified. If
*width* is not specified, then it will be taken from the default
width given in the model.

If the resistance can not be determined from the provided parameters, a fatal error results. This behavior is different from traditional Berkeley SPICE, which provides a default value of 1K.

The paramaters that are understood are:

`m=`*mult*

This is the parallel multiplication factor, that represents the number of devices effectivly connected in parallel. The effect is to multiply the conductance by this factor, so that the given resistance is divided by this value. This overrides the ``m`' multiplier found in the resistor model, if any.`temp=`*temp*

The*temp*is the Celsius operating temperature of the resistor, for use by the temperature coefficient parameters.`tc1=`*tcoeff1*

The first-order temperature coefficient. This will override the first-order coefficient found in a model, if given. The keyword ```tc`'' is an alias for ```tc1`''.`tc2=`*tcoeff2*

The second-order temperature coefficient. This will override the second-order coefficient found in a model, if given.`l=`*length*

The length of the resistor. This applies only when a model is given, which will compute the resistance from geometry.`w=`*width*

The width of the resistor. This applies only when a model is given, which will compute the resistance from geometry.`noise=`*mult*

The*mult*is a real number which will multiply the linear conductance used in the noise equations. Probably the major use is to give`noise=0.0`to temporarily remove a resistor from a circuit noise analysis.`r=`*expr*

This can also be given as ```res=`*expr*'' or ```resistance=`*expr*'', where*expr*is an expression giving the nominal-temperature device voltage divided by device current (``large signal'' resistance) in ohms, possibly as a function of other variables. This form is applicable when the first token following the node list is not a resistance value or model name. It also applies when a model is given, it overrides the geometric resistance value.`poly`*c0*[*c1*...]

This form allows specification of a polynomial resistance, which will take the formResistance =

where*c*0 +*c*1^{ . }*v*+*c*2^{ . }*v*^{2}...*v*is the voltage difference between the positive and negative element nodes. There is no built-in limit to the number of terms.