Laboratory Manual - King Fahd University of Petroleum and Minerals

4. You can use upper or lower case letters.
5. The following subsections explain how to describe elements and use the
control commands.
CIRCUITS ELEMENTS
1. The general format for describing independent voltage source is
Vname N+ N- [DC value] [AC Magn phase] or [SIN V 0 V a freq td df
phase]
Where
The voltage source must start with letter V.
N+ and N- are the positive and negative nodes of the source, respectively.
Sources can be assigned values for dc analysis [DC value], ac analysis [AC
magnitude phase], or transient analysis [SIN].
The ac phase angle is in degrees.
The parameters of the sin are given in this order: dc offset, amplitude, frequency,
delay, damping factor, phase, respectively. In most cases there is no need to
specify td, df, and phase but rather leave SPICE use their default values of
zeroes.
Other the transient signal generators such as PULSE and PWL are introduced in
Experiment 3.
2. An independent current source can be described similarly but using Iname to replace
Vname. But note that current flows from a positive node to the negative node.
3. Various dependent sources are defined when needed in Experiments 3 and 4.
4. Passive elements are described by element statements that specify the type-name and
terminal connections as follows:
Rname N1 N2 value
Cname N1 N2 value
Lname N1 N2 value
5. Semiconductor devices such as diodes, MOSFETs and BJTs are described by two
statements. In addition to an element statement, a model statement is required. SPICE
allows varying degrees of circuit element model complexity. In this tutorial we intend to
provide basic default model descriptions and more complex model descriptions.
Examples will be used to illustrate the differences between the results obtained using
hand calculations, default device models and complex device models. By the end of this
tutorial we expect that the student will get an appreciation of the advantages of using
SPICE complex models. The following subsections briefly described element and model
statements for basic semiconductor devices.
3