Lab

Lab 5 - EE 421L Digital Integrated Circuit Design

Author: Matthew Meza

Email: mezam11@unlv.nevada.edu
September 28, 2015

Design, layout, and simulation of a CMOS inverter!

Pre-lab work

Back-up all of your work from the lab and the course.
Go through Tutorial 3 seen here.

Lab Description

In this lab we will design, layout, and simulate an inverter made of NMOS and PMOS MOSFETs in ON's C5 Process. After the layout, we will plot characterization curves with different loads!

Lab Requirement

Draft schematics, layouts, and symbols for two inverters having sizes of:

12u/6u (= width of the PMOS / width of the NMOS with both devices having minimum lengths of 0.6u)
48u/24u where the devices use a multiplier, M = 4 (set along with the width and length of the MOSFET, image).

Using SPICE simulate the operation of both of your inverters showing each driving a 100 fF, 1 pF, 10 pF, and 100 pF capacitive load.

Use UltraSim (Cadence's fast SPICE simulator for larger circuits at the cost of accuracy) and repeat the above simulations.

Post-Lab Excercises

Inverter Circuits

Inverter1, M=1

Inverter2, M=4 (four devices in parallel)

Inverter1 12u/6u!

Inverter1 Schematic, DRC, LVS

Inverter1 Layout

Inverter2 48u/24u!

Inverter2 Schematic, DRC, LVS

Inverter2 Layout

Capacitave Load Simulations
Inverter 1 (blue output) Inverter 2 (red output)

100fF load; Blue - output!	100fF load; Red - output!
1pF load; notice the RC behavior.	1pF load; the larger MOSFETS are able to supply more current than the smaller MOSFETS in Inverter 1
10pF; the inverter is no longer able to supply sufficient current.	10pF load; notice the RC behavior, the inverter not able to supply enough current fast enough.
100pF; the inverter is completely useless at this load.	100pF; the inverter is no longer able to supply sufficient current.

The same simulations were made using UltraSim. The simulations were exactly the same as the simulations as above but nonetheless can
be found here. The complete Cadence files can be found here.

Return to EE 421 Labs