Environmental Engineering Reference
In-Depth Information
Note that this value is nonzero even if the quiescent value of
equals
zero. Specifically, the body effect arises only if a small signal,
is present
between the source and the bulk terminals. In general
is 0.1-0.2 times
and can be neglected in a non-detailed analysis.
The last model parameter is the resistor which takes into account the
channel length modulation or, which is the same, the dependence of the
drain current on
It is related to the large signal equations by
Substituting in (1.46) the current expression in (1.34) results as
and finally
The high-frequency model of a MOS transistor, which includes the
capacitive effects, is shown in Fig. 1.10.
