Lab 5 The Inverter

Jesse Duran
Spring 2021
ENGR 338

Introduction:

Throughout the course of this lab we will create a schematic of both a 20/10 and 100/50 inverter. We addionally layed out NMOS and PMOS transistors. This builds on the skills we have been developing over the last couple labs

Task 1:


Figure 1. 20/10 Inverter schematic. DRC clean


Figure 2. LTSpice simulation of 20/10 inverter using DC analysis


Figure 3. LTSpice simulation of 20/10 inverter using transant analysis and Pulse function as input

Task 2



Figure 4. 20/10 Inverter layout. DRC clean

Task 3



Figure 5. 100/50 inverter schematic single MOS symbols to represent 5 in parallel. DRC clean


Figure 6. 100/50 Inverter layout. Gates of NMOS and PMOS are shorted together. DCC, NCC clean.

Task 4



Figure 6. LTSpice simulation of 20/10 inverter powering up 100fF capacitor.


Figure 7. LTSpice simulation of 20/10 inverter driving 1pF capactior. Time delay to full charge is larger than 100fF.


Figure 8. LTSpice simulation of 20/10 inverter. Circuit struggling to drive 10pF cap, its is too large.



Figure 9. LTSpice simulation of 100/50 inverter driving 100fF cap.


Figure 10. LTSpice simulation of 100/50 inverter driving 1p Cap. Longer time delay than 100f.


Figure 11. LTSpice simulation of 100/50 inverter powering 10pF cap. Longer time delay than figure 10, however is able to drive circuit compared to 20/10 inverter.

Task 5


Figure 12. ALS simulation schematic. For use with built in Electric VLSI simulation tools. DRC clean


Figure 13. ALS simulation results. Inverted singals for both inverters that are time delayed from the input by about 10ns.


Figure 14. IRSIM simulation of figure 12. There is a noticiable timedelay between input and ouput of the inverters

Discussion

This lab built more skills in reusing schematics and icons as well as introuduced us to different simulation tools available. The Muliplier of the MOS symbols is useful for saving schematic space and preventing over crowding. The different simulations were interestint to manipulate high and low signals, but do not appear to be as applicable as LTSpice. Learning how to use different packages is a good skill to have.