Deborah Barnett, Tidehaven High SchoolTidehaven ISD

Dr. Peng Li, Assistant Professor (faculty mentor)Department of Electrical and Computer EngineeringTexas A & M University

Ping-Hsiu Lee, research partner, Reagan High School, Houston ISD

Digital Circuit Design and Simulations

E3 RESEARCH PROJECT

• Design and analyze circuit functionality and performance.

• Model basic CMOS (Complementary Metal Oxide Semiconductor) transistor behavior using simple switch models.

• Verify graphical analysis (our circuit design) and model behavior using the simulation program PSPICE (an analog circuit and digital logic simulation software that runs on personal computers).

EXAMPLE of a circuit in action when the input is 1

A Y

0 1

1 0

VDD

A=1 Y=0

GND

ON

OFF pMOS transistor

nMOS transistor

CLASSROOM PROJECT OVERVIEW

The student will • investigate the development of the microchip

and its uses in modern technology• construct an electrical transistor and

investigate the physical design of the microchip

• design simple CMOS transistors• use PSPICE to analyze their designs

INTEGRATED CURRICULUM

In ENGLISH I • Focus on technological advances and its

effects • Read articles on microchip design and

development of computer technology• Use basic vocabulary by writing a synopsis of

the articles.

INTEGRATED CURRICULUM

In IPC• Introduce and use the vocabulary (transistors,

resistors, capacitors, nMOS, pMOS, CMOS) and manufacturing processes of CPU’s

• Lab experiment constructing circuits

INTEGRATED CURRICULUM

In ALGEBRA 1• Use examples for graphs and variables from

scientific data, microchip historical data• Use examples for problems from formulas

pertaining to electric circuits• Assignments include data pertaining to digital

circuits, microchips, engineering

Targeted State Standards

English I TEKS: (b.1.a ) Reading/Vocabulary Development. Students understand new vocabulary and use it when reading and writing. Students are expected to determine the meaning of grade-level technical academic English words in multiple content areas.

Targeted State Standards

IPC TEKS: • (3A) analyze and evaluate scientific

explanations using empirical evidence, logical reasoning, and experimental and observational testing

• (5f) evaluate the transfer of electrical energy in series and parallel circuits and conductive materials.

Targeted State Standards

Algebra 1 TEKS:• (1.A) describe independent and dependent

quantities in functional relationships, • (1.D): represent relationships among quantities

using concrete models, graphs, verbal descriptions, and equations,

• (1.E) interpret and make decisions, predictions, and critical judgments from functional relationships,

ALGEBRA 1 TEKS continued

• (2.C) interpret situations in terms of given graphs,

• (2.D) make and interpret scatter plots, and model, predict, and make decisions and critical judgments in problem situations,

• (4.A) find specific function values, • (6.B) interpret the meaning of slope from data

and graphs. • (6.C) predict the effects of change in slope.

PROJECT OBJECTIVESThe student will:• use science vocabulary such as integrated circuit,

transistor, capacitor, ampere, voltage, and resistor appropriately both verbally and in written form.

• determine independent and dependent variables in

problem situations involving current and voltage. • use graphs to determine relationships and make

predictions in problem situations involving integrated circuits.

PROJECT SCOPE AND SEQUENCE

DAY 1IPC: pre-test

DAY 2IPC: LessonDigital andIntegratedCircuitsALG 1: linear functions transformations

DAY 3IPC: LessoncontinuedALG 1: linear functionsmulti-representations

DAY 4IPC: Lessoncontinuedw/ video on electronic technology & ICALG 1: scatterplot

DAY 5IPC: Lesson contENGLISH 1:ResearchALG 1: correlations

DAY 6IPC: Circuit Lab ENGLISH 1:research contALG 1: findline of best fit

DAY 7IPC: Circuit LabcontENGLISH 1:writing assignALG 1: useline of best fit

DAY 8IPC and ALG 1: design circuits by hand ENGLISH 1:writing assign

DAY 9IPC and ALG 1: design circuits by hand

DAY 10IPC and ALG 1:Use PSPICE to validate design

DAY 11IPC and ALG 1:Use PSPICE to validate design

DAY 12ALG 1:post-test

IPC LAB for Series and Parallel Circuits

Kit Components Needed: 12 047MFD capacitor 6 10MFD capacitor 18 100MFD capacitor 6 220PF 200v 6 2N2905A transistor 6 2N3053NPN transistor 12 MPSA06 transistor 12 2N3904 transistor 12 1M ohm resistor 6 1.5K 1/4w resistor 66 100 ohm 1/4w resistor 6 100K 1/4w resistor 12 10K ohm resistor 6 4.7K 1/4w resistor 12 47 ohm resistor 24 470 ohm resistor 12 47K 1/4w resistor 5 500K potentiometer 6 7 segment light detector 6 74S00N integrated circuit 6 74S90N integrated circuit 6 CD4011 integrated circuit 6 CD4511 integrated circuit 6 LM386N integrated circuit 6 LM339 integrated circuit 6 NE555N integrated circuit timer 6 SCL4049A Hex Inverter

integrated circuit 6 1458 integrated circuit 12 IN4148T diode 24 Green LED 6 Red LED 6 Yellow LED 5 Photo cell (LDR) 6 Photo diode infrared detector 10 Loudspeaker 5 Pushbutton momentary switch 5 SPDT miniature slide switch 15pr Alligator clips 5 Breadboard 5 Jumper wire kits 5 Group power supply 5 Digital multimeter 1 Box large paper clips 1 Roll aluminum foil 5 Ball point pens

EXCERPT OF ENGLISH I READING ASSIGNMENT• The design of a transistor allows it to function as an amplifier or a

switch. This is accomplished by using a small amount of electricity to control a gate on a much larger supply of electricity, much like turning a valve to control a supply of water.

Transistors are composed of three parts – a base, a collector, and an emitter. The base is the gate controller device for the larger electrical supply. The collector is the larger electrical supply, and the emitter is the outlet for that supply. By sending varying levels of current from the base, the amount of current flowing through the gate from the collector may be regulated. In this way, a very small amount of current may be used to control a large amount of current, as in an amplifier. The same process is used to create the binary code for the digital processors but in this case a voltage threshold of five volts is needed to open the collector gate. In this way, the transistor is being used as a switch with a binary function: five volts – ON, less than five volts – OFF.

ALGEBRA 1 PROJECT LESSON PLANS

DATE OBJECTIVE/LESSON MATERIALS/RESOURCES METHOD/ACTIVITY

Day 1 IPC gives Pre-Test

Day 2 (1.a): describe independent and dependent quantities in functional relationships(1.D): represent relationships among quantities using concrete models, graphs, verbal descriptions, and equations. (4.A) find specific function values

Graph paperStraight edgeGraphing calculatorExamples/problems related to current, voltage, and resistance

Direct TeachGuided Practice

Day 3 (1.D): represent relationships among quantities using concrete models, graphs, verbal descriptions, and equations. (4.A) find specific function values

Graph paperStraight edgeGraphing calculatorExamples/problems related to capacitors and resistors

Independent practice/pairs

Day 4 (2.C) interpret situations in terms of given graphs,(2.D) make and interpret scatter plots

Graph paperGraphing calculatorExamples/problems related to microchip industry growth, size of microchips

Direct TeachGuided Practice

Day 5 2.D) make and interpret scatter plots, and model, predict, and make decisions and critical judgments in problem situations (correlations)

Graph paperStraight edgeGraphing calculatorExamples/problems related to silicon, CMOS transistors

Direct TeachGuided Practice

ALGEBRA 1 PROJECT LESSON PLANS

DATE OBJECTIVE/LESSON MATERIALS/RESOURCES METHOD/ACTIVITY

Day 6 2.D) make and interpret scatter plots, and model, predict, and make decisions and critical judgments in problem situations (correlations and lines of best fit)

Graph paperStraight edgeGraphing calculatorExamples/problems related to series and parallel circuits

Independent practice/pairs

Day 7 (2.D) make and interpret scatter plots, and model, predict, and make decisions and critical judgments in problem situations (correlations and lines of best fit)

Graph paperStraight edgeGraphing calculatorExamples/problems related to nMOS and pMOS transistors

Independent practice/pairs

Day 8 Design simple circuits and analyze using logic table Blank paper Direct TeachGuided Practice

Day 9 Design simple circuits and analyze using logic table Blank paper Independent practice/pairs/teams

Day 10 Validate circuit designs using PSPICE Computer lab Pairs

Day 11 Validate circuit designs using PSPICE Computer lab Pairs

Day 12 Project Post-test

Example to Use

Another Example

PRE/POST-TEST

FOCUS• Questions 1 - 10 are technical vocabulary related to the project and general questions

related to engineering• Question 11 - 20 are Algebra 1 skills related to

the project

SOME OF THE QUESTIONSMatching a. resistor b. capacitor c. transistor d. silicon ____1. A device used in electronic circuits that provides semi-conductivity is called a ? ____2. ? is a nonmetallic chemical element with low electrical conductivity. ____3. A device used in electronic circuits that holds a charge of electricity is called a ? ____4. A device used in electronic circuits used to control the flow of current is called a ?

SOME MORE QUESTIONSMultiple Choice

Identify the choice that best completes the statement or answers the question.

 

____5. Persons concerned with developing economical and safe solutions to practical problems by applying mathematics and scientific knowledge are _?_.

a. teachers c. policemen

b. salesmen d. engineers

 

 ____ 6. An engineer is developing a method to be used for future space travel which will change urine into drinking water without using toxic chemicals. He/she is a/an _?_ engineer.

a. nuclear c. industrial

b. environmental civil d. petroleum

____7. An engineer is testing the strength of the concrete used in bridge building by applying thousands of pounds of pressure to see when the concrete will collapse and crumble. He/she is a/an _?_ engineer.

a. petroleum c. nuclear

b. structural civil d. chemical

a. 5 ohms c. 0.5 ohmsb.

2 ohms d.

0.2 ohms

____19. Use the formula V = IR for the following problem. V represent voltage, R represent resistance (ohms) and I represents electrical current (amperes). If an electric light bulb draws a current of 1.2 amperes at 6 volts, what is the resistance?

PSPICE Demonstration

Step 1: Access the library using key strokes: Control G

Scroll through library and click on MBREAKN3which is the nMOS transistor.

It should look like this……

LIBRARY

Click and drag the MBREAKN3 into position

You will end up with this……

This is an nMOS transistor

Step 2:Access library again with Control G and select

VDC

VDC is voltage direct current power supply. The voltage measurement in an DC system.

Click and drag twice to put 2 VDC’s on the schematic design. It should look as follows.

Step 3:Access library again with Control G and select a

ground. Click on GND_EARTH.

Click and drag 3 times to set the grounds. It should look as follows.

GROUNDS

Step 4:Click on V1 and change the name to Vd.

Click on V2 and change the name to Vg.

Click on the pencil on the Tool Bar and draw the wires to connect the nMOS transistor. It should look as follows.

Click on the current icon to set probeAnalysis Simulation

Step 5:Set analysis for a DC Sweep for the Vd source

and a nested sweep for the Vg source.

Click on Simulation and the following analysis will appear.

ACKNOWLEDGEMENTS• Dr. Peng Li, faculty mentor, Dept of Electrical and Computer Engineering,

Texas A & M University• Albert Zeng, PhD student, Dept of Electrical and Computer Engineering,

Texas A & M University• TAMU E3 participating faculty• National Science Foundation (NSF)• Ping-Hsiu Lee, research partner, Reagan High School, Houston ISD

THANK YOU ALL FOR A GREAT EXPERIENCE!