AC Load Line

Equation (103) describes the AC load line, Figure 113, since it says

$\begin{displaymath}i_{c} = - \frac{v_{ce}}{R_C} . \end{displaymath}$

which has slope -1/R_C.

**Figure 113:** AC load line for the circuit of Figure 110.
$\begin{figure} \begin{center} \epsfig{file=images/bjtimg12a.eps}\end{center}\end{figure}$

In comparison, the DC load line is given by equation (102), and has slope -1/(R_E+R_C).

The difference is due to the fact that R_E is shorted out to AC signals, but not to DC.

ANU Engineering - ENGN2211