day08

1. Tasks

Build an inverter in LTspice:

Use the models from c5.txt
λ = 0.3 μm
L=2λ and P/N widths of 10λ / 5λ. Use parameter expansion to compute the numerical values in the transistor instance parameters, e.g. L={lambda*2}.
Vdd power supply of 5 V
Input signal called Vsignal with series 1 Ω resistor Rsignal (to model the Thevenin-equivalent output impedance of the signal source)
Label the inverter input in
Label the inverter output x1
Inverter load capacitance C1 of 10 fF

Open the LTspice Help manual:

Sweep Vsignal linearly from 0 to 5 V in 1 mV increments and plot V(x1) vs V(in).

Mark the regions where the N and P transistors are in {cutoff, linear, saturation} modes.
Measure the switching voltage \(V_t\) (\(V_{in}=V_{out}\)) using cursors.
Measure \(V_t\) using .measure command(s).
Find the two \(V_{in}\) values where \(\dfrac{d V_{out}}{d V_{in}} = -1\). These are VIL, VIH, VOL, VOH.
- Estimate using the cursor.
- Plot the output derivative using a computed waveform in the plot window.
- Directly measure+compute the values with .measure commands.

Update the transistor parameters to also include drain/source areas and perimeters. These should be parameterized by the transistor width.