Laboratory Manual - King Fahd University of Petroleum and Minerals

Detailed model parameters are provided in Table 2.
MOS Field Effect Transistor
The n-channel and p-channel MOSFET element models are given in Figure 3. The
element statement format is
Mname ND NG NS NB MNAME W=VALW L=VALL
ND
ND
NG
NB
NG
NB
NS
NS
5
NMOS
PMOS
Figure 3: MOSFET types.
The associated model statements is for N-channel
.MODEL MNAME NMOS [PNAME1=PVAL1 PNAME2=PVAL2…]
and for P-channel
.MODEL MNAME PMOS[PNAME1=PVAL1 PNAME2=PVAL2…]
Detailed model parameters are provided in Table 3. Note that the default values for the
gate length, VALL, and the gate width, VALW, are 1cm. Obviously, these are not
realistic values; however, the model uses the ratio of VALL and VALW rather than the
individual values in its calculations.
CONTROL COMMANDS
.OP
The inclusion of the statement .OP makes SPICE perform DC analysis to find the
operating point of the circuit.
.AC Sweep-mode NP START STOP
The .AC control statement is used to perform ac analysis on a circuit and provide
data for frequency response plotting.
Where Sweep-mode is one of the keywords that’s indicates the frequency
variation by decade (DEC), by octave (OCT), or linearly (LIN).
NP is the number of points per sweep-mode;
FSTART is the starting frequency. FSTART cannot be zero.