CE 338 2021 Spring
Lab 5: The Inverter
Nic Theobald
nstheobald@fortlewis.edu


The Inverter

Introduction

This lab covers the design and simulation a single transistor inverter and a 5 transistor inverter. The inverters' ability to drive different load capacitors was simulated using LTspice and ALS. The time delay is clearly shown in the simulation plots. It can be seen that the 5 transistor inverter is significantly more powerful than the single transistor inverter.

Methods and Materials



Item
Quantity


LTspice
Electric VLSI
Ideal ADC/DAC Library
1
1
1



The schematic of the inverter was first created and simulated (Figure 1, 2). The layout of the inverter was then created and simulated. The 5 transistor wide inverter was adapted from the single transistor wide inverter. The schematic and layout of the 5 transistor wide inverter was then simulated with different load capacitors. The single transistor wide inverter was also simulated with the same capacitors. A circuit containing both inverters was then simulated using ALS and LTspice. The time delay of both inverters is clearly shown in the LTspice simulations.

Results

Task 1: Create Schematic of Inverter

The schematic of the inverter is first created.
Figure 1: Schematic view of the inverter.

The schematic was then simulated in LTspice. The first using a dc sweep and the second using a pulse function.


Figure 2:Simulation on inverter.

Task 2: Create Layout for the Inverter


The layout of the inverter was then created.
Figure 3: Layout view of the inverter.

The layout was then simulated.
Figure 4: Simulation of inverter.


Task 3: Create Schematic of 5x Inverter

The schematic and layout of the inverter are first created.
Figure 5: Schematic and layout view of the 5x inverter.


Figure 6: DRC, ERC, and NCC checks for the 5x inverter.
Task 4: Run Simulations of 5x Inverter

Simulation of normal inverter:
100f

1p
10p

Simulation of the 5x inverter:
100f

1p
10p

Task 5: ALS Simulation

A schematic was created and simulated using ALS.
Figure 7: Schematic and simulation using ALS.

Task 5: LTspice Simulation (Instead of IRSIM)

The IRSIM simulation package didn't work. The schematic for IRSIM was changed and simulated using LTspice.
Figure 8: Schematic and simulation using LTspice.

Discussion:

This lab detailed the design and simulation of a single transistor inverter and a 5 transistor inverter. The ability of the inverter to drive different capacitors is shown in their respective simulations. The included ALS simulation software was also used to demonstrate the two inverters driving capabilities.