Delay estimation

The delay estimation of the structures reported in figure 3.2 implies the evaluation of $\tau_{o_{n,p}}^i$ and $t_{0_{n,p}}^i$, for each transistor in the chains.

The currents in each transistor can be obtained from equations (3.1), (3.2) (page ), with the voltage function of time defined in equations (3.4a)-(3.4f) (page ). So we can calculate the quantity of charge at each node and thus apply the charge conservation law, i.e. at each node the total charge variation must be equal to zero:

$$Q_n^i = 0 \quad Q_p^j = 0 \qquad {\mathstrut i=1,2,\dotsc N} \;\textrm{and}\;{\mathstrut j=1,2,\dots,P}$$ (4.6)

The generic term $Q_{n}^i$ is the sum of three elements, $Q_{n}^i = Q_{I}^{i+1}-Q_{I}^i-Q_{C}^i$, define below:

$$\item $Q_I^{i+1}$\ is the charge due to the $(i+1)$--th {\sc mosf... ... the $i$--th node, $C^i$: \begin{equation}Q_C^i= C^i V_{d_n}^i\;.\end{equation}$$ (4.7a)

Similarly equations apply for p-MOSFET.

For each circuit node, a charge conservation equation can be written.