Intro to Engineering Electronics Lecture 3: Transistors Introduction to some broadly useful concepts in Electrical and Computer Engineering Intro to Engineering Electronics STOLEN FROM K. A. Connor 11/29/2018

Intro to Engineering Electronics Review Voltage, Current Ohm’s Law Kirchoff’s Laws for Voltage and Current Equivalent Resistance Series Combinations Parallel Combinations Diode I-V Characteristics Intro to Engineering Electronics STOLEN FROM K. A. Connor 11/29/2018

Intro to Engineering Electronics Ohm’s Law Kirchoff’s Voltage Law Kirchoff’s Current Law Series Equivalent Parallel Equivalent Intro to Engineering Electronics STOLEN FROM K. A. Connor 11/29/2018

Intro to Engineering Electronics STOLEN FROM K. A. Connor 11/29/2018

Intro to Engineering Electronics Voltage Across REQ1 Intro to Engineering Electronics STOLEN FROM K. A. Connor 11/29/2018

Resistor V-I Characteristic Resistors obey Ohm’s Law Voltage is proportional to Current Voltage vs. Current is a straight line Intro to Engineering Electronics STOLEN FROM K. A. Connor 11/29/2018

Diode V-I Characteristic For ideal diode, current flows only one way Real diode is close to ideal Ideal Diode Intro to Engineering Electronics STOLEN FROM K. A. Connor 11/29/2018

Transistor: A Combination of 2 Diodes Intro to Engineering Electronics STOLEN FROM K. A. Connor 11/29/2018

Intro to Engineering Electronics Diodes We have noted previously that diodes act like a flapper valve Intro to Engineering Electronics STOLEN FROM K. A. Connor 11/29/2018

Intro to Engineering Electronics Transistor 2 P-N Junctions Intro to Engineering Electronics STOLEN FROM K. A. Connor 11/29/2018

Intro to Engineering Electronics MOSFET Applying a gate voltage that exceeds the threshold voltage opens up the channel between the source and the drain This is from an excellent collection of java applets at SUNY Buffalo http://jas.eng.buffalo.edu/ Intro to Engineering Electronics STOLEN FROM K. A. Connor 11/29/2018

Intro to Engineering Electronics STOLEN FROM K. A. Connor 11/29/2018

2 Minute Quiz Connect the Items on the Left With Those on the Right Name________________ 2 Minute Quiz Connect the Items on the Left With Those on the Right Section________ Date__________ Kirchoff Voltage Law R/2 Voltage V divided by Current I The sum of all currents into a node is zero KVL Resistance R Intro to Engineering Electronics STOLEN FROM K. A. Connor 11/29/2018

Intro to Engineering Electronics Transistor Models 2 Diodes Current enters one terminal, is controlled by a second terminal and exits the third terminal. Thus, it acts like a valve. Valves can be fully open, fully closed, or part way open Intro to Engineering Electronics STOLEN FROM K. A. Connor 11/29/2018

Transistor Models Continued If the control signal changes with time, the total current passing through the transistor changes in the same way, but at a much higher amplitude Intro to Engineering Electronics STOLEN FROM K. A. Connor 11/29/2018

Transistor Models Continued Simple circuit model of transistor Intro to Engineering Electronics STOLEN FROM K. A. Connor 11/29/2018

Transistor Models Continued Transistor as a switch Intro to Engineering Electronics STOLEN FROM K. A. Connor 11/29/2018

Transistor Models Continued Transistor as logic gate (Inverter) Input Output 1 Intro to Engineering Electronics STOLEN FROM K. A. Connor 11/29/2018

2 Minute Quiz Connect the Items on the Left With Those on the Right Name________________ 2 Minute Quiz Connect the Items on the Left With Those on the Right Section________ Date___________ Kirchoff Voltage Law R/2 Voltage V divided by Current I The sum of all currents into a node is zero The parallel combination of two equal resistors R Intro to Engineering Electronics STOLEN FROM K. A. Connor 11/29/2018

Intro to Engineering Electronics Models There are usually many, many models for engineering devices and systems Models vary in sophistication and complexity You can use a model that you understand fully or that you are sure you are applying correctly Use the simplest model that contains the information required Intro to Engineering Electronics STOLEN FROM K. A. Connor 11/29/2018

Intro to Engineering Electronics Models Continued Circuit components usually require more complex models at High frequency High power High or low temperature High levels of radiation Small size Intro to Engineering Electronics STOLEN FROM K. A. Connor 11/29/2018

Intro to Engineering Electronics Models: Logic Gates Intro to Engineering Electronics STOLEN FROM K. A. Connor 11/29/2018

Intro to Engineering Electronics Logic Gate: XOR (a) Question: What common household switch configuration corresponds to an XOR? Input Output A B X 1 Intro to Engineering Electronics STOLEN FROM K. A. Connor 11/29/2018

Intro to Engineering Electronics Models: Black Boxes Logic gate models are examples of Black Boxes The inner workings of the model are not of interest There is a well-defined relationship between the input and the output Intro to Engineering Electronics STOLEN FROM K. A. Connor 11/29/2018

Intro to Engineering Electronics Black Box Examples Amplifier Logic Ckt XOR Gate Intro to Engineering Electronics STOLEN FROM K. A. Connor 11/29/2018

Intro to Engineering Electronics Clapper Circuit Intro to Engineering Electronics STOLEN FROM K. A. Connor 11/29/2018

Models: Black Boxes Cont. Signals and Systems Intro to Engineering Electronics STOLEN FROM K. A. Connor 11/29/2018

2 Minute Quiz Connect the Items on the Left With Those on the Right Name________________ 2 Minute Quiz Connect the Items on the Left With Those on the Right Section________ Date____________ Kirchoff Voltage Law R/2 Voltage V divided by Current I The sum of all currents into a node is zero KCL Intro to Engineering Electronics STOLEN FROM K. A. Connor 11/29/2018

Answers Connect the Items on the Left With Those on the Right Name________________ Answers Connect the Items on the Left With Those on the Right Section________ Date____________ KVL Resistance R Kirchoff Voltage Law R/2 Voltage V divided by Current I The sum of all currents into a node is zero The parallel combination of two equal resistors R KCL Intro to Engineering Electronics STOLEN FROM K. A. Connor 11/29/2018

Where Will You See This Information Next? V, I, R, Kirchoff’s Laws, Combining Resistors: ECSE-2010 Electric Circuits Diode and Transistor Theory and Electronic Design: ECSE-2050 Analog Electronics, ECSE-2060 Digital Electronics and ECSE-2210 Microelectronics Technology Logic Design: ECSE-2610 Computer Components and Operations Signals and Black Box Models: ECSE-2410 Signals and Systems Intro to Engineering Electronics STOLEN FROM K. A. Connor 11/29/2018