Digital Logics : Theory and Practicals

Digital Logic series IC mainly are of two types:
1. 7400 series TTL logic
2. 4000 series CMOS logic
all general logic ICs fall under these categories.Let's have a quick overview.

The 7400 series of integrated circuits (ICs) are the most popular logic families. In 1964, Texas Instruments introduced the first members of their ceramic package SN5400 series transistor–transistor logic (TTL) logic chips, later a low-cost plastic package SN7400 series was introduced in 1966 which quickly gained over 50% of the logic chip market, and eventually becoming de facto standardized electronic components. Over the decades, many generations of pin-compatible descendant families evolved to include support for low power CMOS technology, lower supply voltages, and surface mount packages.[6] The 7400 series contains hundreds of devices that provide everything from basic logic gates, flip-flops, and counters, to special purpose bus transceivers and arithmetic logic units (ALU). Specific functions are described in a list of 7400 series integrated circuits

The 4000 series was introduced as the CD4000 COS/MOS series in 1968 by RCA as a lower power and more versatile alternative to the 7400 series of transistor-transistor logic (TTL) chips. The logic functions were implemented with the newly introduced Complementary Metal–Oxide–Semiconductor (CMOS) technology.
Below you can watch the detailed video on the 7400 and 4000 logics.

Click here to see the complete list of 7400 and 4000 logics, Source: Wikipedia.

1 / 6

Basic logic gates
Digital electronics relies on the actions of just seven types of logic gates, called AND, OR, NAND (Not AND), NOR (Not OR), XOR (Exclusive OR) XNOR (Exclusive NOR) and NOT. Here's a quick video on simulating basic logic gates using Multisim simulation software.


2 / 6
Decoder is a combinational circuit that has ‘n’ input lines and maximum of 2n output lines. One of these outputs will be active High based on the combination of inputs present, when the decoder is enabled. That means decoder detects a particular code. The outputs of the decoder are nothing but the min terms of ‘n’ input variables lines, when it is enabled.
Below is practical video on decoder which will cover theroy as well as practical.


3 / 6
Multiplexer is a combinational circuit that has maximum of 2n data inputs, ‘n’ selection lines and single output line. One of these data inputs will be connected to the output based on the values of selection lines. Since there are ‘n’ selection lines, there will be 2n possible combinations of zeros and ones. So, each combination will select only one data input. Multiplexer is also called as Mux.

The following two videos will cover more theory, simulation and practical implementation of multiplexers.


4 / 6
Shift Register
We know that one flip-flop can store one-bit of information. In order to store multiple bits of information, we require multiple flip-flops. The group of flip-flops, which are used to hold store the binary data is known as register.If the register is capable of shifting bits either towards right hand side or towards left hand side is known as shift register. An ‘N’ bit shift register contains ‘N’ flip-flops. Following are the four types of shift registers based on applying inputs and accessing of outputs.
1. Serial In − Serial Out shift register
2. Serial In − Parallel Out shift register
3. Parallel In − Serial Out shift register
4. Parallel In − Parallel Out shift register


5 / 6
Display Drivers
In Electronics/computer hardware a display driver is usually a semiconductor integrated circuit (but may alternatively comprise a state machine made of discrete logic and other components) which provides an interface function between a microprocessor, microcontroller, ASIC or general-purpose peripheral interface and a particular type of display device, e.g. LCD, LED, OLED, ePaper, CRT, Vacuum fluorescent or Nixie.
Below we have a simulation on 7447 display driver.

Click on this link for using a CD4511 based display driver


6 / 6
Flip Flops
In electronics, a flip-flop or latch is a circuit that has two stable states and can be used to store state information – a bistable multivibrator. The circuit can be made to change state by signals applied to one or more control inputs and will have one or two outputs. It is the basic storage element in sequential logic. Flip-flops and latches are fundamental building blocks of digital electronics systems used in computers, communications, and many other types of systems. Here we will see a theory and practical video on JK & D flip flop.


Click once to pause slideshow

The following video series contains the full playlist. Check it out.

  1. clock
    Digital Clock using Counters and Display Drivers

  2. car
    Line follower and Obstacle Detector using logic gates

  3. Shift Register (74595) Based 7 segment display Board

  4. ADC using opamps & Priority Encoder (74148)

Note:Designed by Team Watchdogs. Best viewed at Chrome and Mozilla. Thank You