Transcript Document
Lecture 3: Transistors Introduction to some broadly useful concepts in Electrical and Computer Engineering 7/16/2015 Intro to Engineering Electronics STOLEN FROM K. A. Connor 1 Review • • • • Voltage, Current Ohm’s Law Kirchoff’s Laws for Voltage and Current Equivalent Resistance Series Combinations Parallel Combinations • Diode I-V Characteristics 7/16/2015 Intro to Engineering Electronics STOLEN FROM K. A. Connor 2 Ohm’s Law V IR Kirchoff’s Voltage Law V 0 Kirchoff’s Current Law I IN IOUT Series Equivalent REQ R1 R2 ... RN 1 1 1 1 ... Parallel Equivalent REQ R1 R2 RN 7/16/2015 Intro to Engineering Electronics STOLEN FROM K. A. Connor 3 R1 1k V V V1 V O FF = 0 V AMP L = 1 F RE Q = 10k R2 R3 1k 1k 0 REQ1 R2 R3 1k 1k 0.5k R2 R3 1k 1k V 1V I 0.67mA R1 REQ1 15 . k 7/16/2015 Intro to Engineering Electronics STOLEN FROM K. A. Connor 4 Voltage Across REQ1 V I REQ1 0.67mA 05 . k 033 . V 1.0V 0V -1.0V 0s 50us V(R1:1) 100us 150us 200us 250us 300us 350us 400us V(R1:2) Time 7/16/2015 Intro to Engineering Electronics STOLEN FROM K. A. Connor 5 Resistor V-I Characteristic • Resistors obey Ohm’s Law V I • Voltage is proportional to Current • Voltage vs. Current is a straight line R 10mA 5mA V-I Characteristic of a 500 Ohm Resistor 0A -5mA -10mA -6.0V I(R1) -4.0V -2.0V 0V 2.0V 4.0V 6.0V V(R1:1) - V(R1:2) 7/16/2015 Intro to Engineering Electronics STOLEN FROM K. A. Connor 6 Diode V-I Characteristic • For ideal diode, current flows only one way • Real diode is close to ideal Ideal Diode 7/16/2015 Intro to Engineering Electronics STOLEN FROM K. A. Connor 7 Transistor: A Combination of 2 Diodes 7/16/2015 Intro to Engineering Electronics STOLEN FROM K. A. Connor 8 Diodes • We have noted previously that diodes act like a flapper valve 7/16/2015 Intro to Engineering Electronics STOLEN FROM K. A. Connor 9 Transistor 2 P-N Junctions 7/16/2015 Intro to Engineering Electronics STOLEN FROM K. A. Connor 10 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/ 7/16/2015 Intro to Engineering Electronics STOLEN FROM K. A. Connor 11 7/16/2015 Intro to Engineering Electronics STOLEN FROM K. A. Connor 12 Name________________ Section________ Date__________ • KVL • Resistance R 7/16/2015 2 Minute Quiz Connect the Items on the Left With Those on the Right • Kirchoff Voltage Law • R/2 • Voltage V divided by Current I • The sum of all currents into a node is zero Intro to Engineering Electronics STOLEN FROM K. A. Connor 13 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 7/16/2015 Intro to Engineering Electronics STOLEN FROM K. A. Connor 14 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 I C I B 7/16/2015 Intro to Engineering Electronics STOLEN FROM K. A. Connor 15 Transistor Models Continued • Simple circuit model of transistor 7/16/2015 Intro to Engineering Electronics STOLEN FROM K. A. Connor 16 Transistor Models Continued • Transistor as a switch 7/16/2015 Intro to Engineering Electronics STOLEN FROM K. A. Connor 17 Transistor Models Continued • Transistor as logic gate (Inverter) Input 0 1 7/16/2015 Output 1 0 Intro to Engineering Electronics STOLEN FROM K. A. Connor 18 2 Minute Quiz Name________________ Section________ Date___________ Connect the Items on the Left With Those on the Right • The parallel combination of two equal resistors R 7/16/2015 • Kirchoff Voltage Law • R/2 • Voltage V divided by Current I • The sum of all currents into a node is zero Intro to Engineering Electronics STOLEN FROM K. A. Connor 19 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 7/16/2015 Intro to Engineering Electronics STOLEN FROM K. A. Connor 20 Models Continued • Circuit components usually require more complex models at High frequency High power High or low temperature High levels of radiation Small size 7/16/2015 Intro to Engineering Electronics STOLEN FROM K. A. Connor 21 Models: Logic Gates 7/16/2015 Intro to Engineering Electronics STOLEN FROM K. A. Connor 22 Logic Gate: XOR (a) Input A 0 0 1 1 7/16/2015 Input B 0 1 0 1 Output X 0 1 1 0 Question: What common household switch configuration corresponds to an XOR? Intro to Engineering Electronics STOLEN FROM K. A. Connor 23 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 7/16/2015 Intro to Engineering Electronics STOLEN FROM K. A. Connor 24 Black Box Examples • Amplifier • Logic Ckt XOR Gate 7/16/2015 Intro to Engineering Electronics STOLEN FROM K. A. Connor 25 Clapper Circuit 7/16/2015 Intro to Engineering Electronics STOLEN FROM K. A. Connor 26 Models: Black Boxes Cont. • Signals and Systems 7/16/2015 Intro to Engineering Electronics STOLEN FROM K. A. Connor 27 Name________________ Section________ Date____________ • KCL 7/16/2015 2 Minute Quiz Connect the Items on the Left With Those on the Right • Kirchoff Voltage Law • R/2 • Voltage V divided by Current I • The sum of all currents into a node is zero Intro to Engineering Electronics STOLEN FROM K. A. Connor 28 Name________________ Section________ Connect the Items on the Left With Those on the Right Date____________ KVL Resistance R •The parallel combination of two equal resistors R • KCL 7/16/2015 Answers • Kirchoff Voltage Law • R/2 • Voltage V divided by Current I • The sum of all currents into a node is zero Intro to Engineering Electronics STOLEN FROM K. A. Connor 29 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, ECSE2060 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 7/16/2015 Intro to Engineering Electronics STOLEN FROM K. A. Connor 30