UTPA STEM/CBI Courses/Introduction to VLSI

Course Title: Introduction to VLSI

Lecture Topic:A basic Switch deign using CMOS technology

Instructor: Hasina Huq

Institution: UTPA

Backwards Design

Course Objectives

• Primary Objectives- By the next class period students will be able to:
  • learn CMOS design concept
  • learn to design NOT gate in CMOS technology

• Sub Objectives- The objectives will require that students be able to:
  • understand logic gates
  • understand characteristics of MOSFET

• Difficulties- Students may have difficulty:
  • Remembering the operating conditions of MOSFET
  • Remembering the I-V characteristics of NMOS
  • Remembering the I-V characteristics of PMOS

• Real-World Contexts- There are many ways that students can use this material in the real-world, such as:
  • How does a traffic light work?
  • How does an on-off switch work?

Model of Knowledge

• Concept Map
  • Identify common switching situation needed in everyday engineering applications.
  • Relate swithing concept to MOSFET operating condition
  • Apply knowledge gained from previous course (digital I)

• Content Priorities
  • Enduring Understanding
    • Understanding the conditions of a PMOS/NMOS operating in saturation region
    • Understanding the conditions of a PMOS/NMOS operating in triode region
    • Understanding the cut off state conditions of a PMOS/NMOS
    • Understanding the threshold voltage,aspect ratio, risetime, fall time, propagation delay

• Important to Do and Know
  • Become familiar with the MOSFET input, output characteristics

• Worth Being Familiar with
  • Relations between MOSFET and BJT

Assessment of Learning

• Formative Assessment
  • In Class/Lab (groups)
    • Discussion of a NOT/ inverter logic gate structure in transistor level using CMOS concept
    • Discussion on the number of PMOS and NMOS needed to design an NOT gate
    • Discussion of the terminals: i.e. input, output, ground, supply voltage
  • Homework (individual)
    • problems /Questions on a simple NOT gate with diffrent aspect ratio
    • Calculation of the risetime, fall time, propagation delay from the gate

• Summative Assessment
  • Quiz on lecture and home work problems
  • Exam on lecture and home work problems

Legacy Cycle

OBJECTIVE

By the next class period, students will be able to:

• learn to design NOT gate in CMOS technology

The objectives will require that students be able to:

• Understand the characteristics of MOSFET

THE CHALLENGE

As an electrical engineer you are called on behalf of the defendant who is involved in a car accident at an intersaction in Edinburg. The accident leaves the victim (car driver) paralyzed below the waist. It is reported that the reason of the accident is the red light violation. The defendant has witnesses that account for her speed limit, but the defendant is unable to provide an evidence that she did not violate the red light.

Accident.

Accident.

GENERATE IDEAS

1. How did the reporter arrive at the violation of red light? 2. What information you need to challenge the reporter?

MULTIPLE PERSPECTIVES

Lectures/Text Book

RESEARCH & REVISE

1. Examine the swithing characteristics of the traffic light 2. Relate that one with MOSFET swithing and/or operating characteristics 3. Computation of the switching spped of MOSFET 4. Literature reserach for propogation delay,rise time, fall time 5. Revision of the model, threshold voltage

TEST YOUR METTLE

Homework assignment related to switching problem

GO PUBLIC

Quiz, exam that apply concepts to unrelated application

Pre-Lesson Quiz

1. What is the operating condition of a MOSFET?
2. What type of threshold voltage you need to turn on a PMOS?
3. What type of threshold voltage you need to turn on an NMOS?
4. what is the input characteristics of a MOSFET
5. what is the output characteristics of a MOSFET
6. What is aspect ratio?
7. How to calculate propagation delay, rise time , Fall time

Test Your Mettle Quiz

1. True or False

Positive gate voltage is needed at the gate of a PMOS.