Resistors

- General Form:
`r`*name**n1 n2*[*value*|*modname*] [r=*expr*] [temp=*temp*[tc1=*tcoeff1*] [tc2=*tcoeff2*]

[l=*length*] [w=*width*] [noise=*mult*]

r*name**n1 n2*`poly`*c0*[*c1*...]

- Examples:
`rload 2 10 10k`

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

The nominal-temperature resistance value can be specified as a bare number, if it is the first parameter following the node list. This token can also be a resistor model name. The paramaters that can follow are:

`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.`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.

The second form allows specification of a polynomial resistance, which will take the form

Resistance =wherec0 +c1^{ . }v+c2^{ . }v^{2}...

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 *value* 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.