Introductory Lecture on Digital Electronics Electronics Club Introductory Lecture on Digital Electronics

Why Learn Digital ?? Is it because computers are digital or the world is going Digital ?? As Samsung says “The new realm of DigitAll Technology” One to One functions Virtually immune to noise Easy to rectify mistakes ( Why?? )

What is Digital Electronics?? A Digital circuit is based on a number of discrete voltage levels, as distinct from an analog circuit that uses continuous voltages to represent variables directly. In most cases the number of states is two, and these states are represented by two voltage levels: one near to zero volts and one at a higher level depending on the supply voltage in use. These 2 discrete states might be called “Low” and “High”, 1 or 0 , True or False. Simple intuitive Boolean algebra !!!!

Wanna See Noise Immunity !! Technology Low Level High Level Supply Voltage CMOS 0 to Vcc/2 Vcc/2 to Vcc Vcc = 5V TTL 0 to 0.8V 2V to Vcc

What is common to Digital Circuits?? Supply Voltage  5V (at the club ) A term called CLOCK Will you change Mr. Logical One Mr. Clock Says : Yes Sir !! Right away Mr. Logical One Responds:

In Electronics Terms A clock is simply a square wave , which is mostly common to all components put in a digital circuit. We may classify it as a parameter in measuring speed of the circuit. A Logical One 5V 0V A Logical Zero

The Binary Number System Representing Nos. as a sequence of 1’s and 0’s. Nos. in Base 2 Decimal to Binary Conversion Binary to Decimal Conversion Intuitivism here too!!!!

Logic Gates Simple Boolean functions AND OR NOT XOR NAND NOR

AND Gate Y = A & B Input 1(A) Input 2(B) Output (Y) Input 1 Input 2 1 Y = A & B

OR Gate Y = A | B Input 1 (A) Input 2 (B) Output (Y) Input 1 Input 2 1 Y = A | B

NOT Gate Input A Output Y Input Output 1 Y = ~A

XOR NOR NAND XNOR Gates A B A XOR B 1 A B ~(A&B) 1 A B A XNOR B 1 A B 1 A B ~(A&B) 1 A B A XNOR B 1 A B ~(A|B) 1

Dear Transistor Most simple use as a switch Supply Load Device Input

You did not understand something ??? Read the handout Even better come to the workshop Lets work One to One  Register for the workshop Finally Be there !!!!

Thank You