How analog and digital difference in electronics

My students (children) ask me what is the difference between analog and digital.  Is it a good question?  We will answer him how? clear and easy…

analog and digital difference in electronics

Have we heard each other? Both the words such as any audio or video is transformed into electrical signals.

And do you know two words are different?

In short, analog technology information is translated into a signal that varying amplitude. And It should be smooth and continuous.

In digital technology, information is into one and zero formats. We called binary. Each bit is two distinct amplitudes.

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What is an Analog Signal?

It is a continuous Data. There is a varying signal amplitude. The change in signal size is gradual and a curve.

Which one time-varying quantity represents another time-based variable.


Analog Signal

We will see this type of signal works around us, with physical values and natural. For example, frequency, voice, wind, wave, weight, lighting, etc.

Can you see a clearer image yet?

In electronics also there is a lot of analog forms. For example:

The output from LDR (light sensor), Microphone, Audio, Any frequency, etc.

A power amplifier
It is another example of an analog system. The power amplifier will produce the output voltage. Which any value within the range of its power supply.

Analog meter
It can display any value within the range available on the scale. However, accuracy is limited by our ability to read.
Look at Galvanometer 0-1mA


Learn: How to use an analog meter 

For example, The meter shows 0.25mA. Its needle is pointed at about halfway between 0.2mA and 0.4mA.  But we can’t read the scale more than half the mark.

Noise in Analog circuits

All electronic circuits suffer from noise signals. This is an unwanted signal, mixed with the desired signal.

For example, an amplifier can pick up and hum from AC mains (50Hz AC main). It is difficult to eliminate the noise from the Analog signal. Because it is difficult to distinguish between interference and the desired signal

Pros of Analog Signals

  • Easier in processing
  • Best suited for audio and video transmission.
  • It has a low cost and is portable.
  • It has a much higher density so that it can present more refined information.
  • Not necessary to buy a new graphics board.
  • Uses less bandwidth than digital sounds
  • Provide a more accurate representation of a sound
  • It is the natural form of a sound.

Cons of Analog Signals

  • Lower quality signal than digital.
  • The cables are sensitive to external influences.
  • The cost of the Analog wire is high and not easily portable.
  • Low availability of models with digital interfaces.
  • Recording analog sound on tape is quite expensive if the tape is damaged
  • It offers limitations in editing
  • The tape is becoming hard to find
  • It is quite difficult to synchronize analog sound
  • Quality is easily lost
  • Data can become corrupted
  • Plenty of recording devices and formats which can become confusing to store a digital signal
  • Digital sounds can cut an analog sound wave which means that you can’t get a perfect reproduction of a sound
  • Offers poor multi-user interfaces

What is Digital Signal?

The signals are associated with Discrete Data. Have a certain size. They may jump between two values: the highest signal and the lowest signal.

Or discrete steps like either 0V or 5V. Timing graphs of these signals look like square waves. Or we called Logic states.

Look at the square wave signal

Digital Signal

Digital systems are made up of devices such as logic gates, flip-flops, shift registers, and counters. Computers are an example of digital systems.

Today we prefer to use a Microcontroller like Arduino to replace a normal analog.

What is more?

Digital Meter
An example of a digital circuit closest to us is a digital multimeter. We can use it to read many values and have higher accuracy than an analog meter.

Digital multi meter

Credit: Photo Equus

Not only that I want to explain to you about this, too

LEARN: Relationship Between Current and Voltage

Logic states

Most digital systems use a simple signal type. Which has only two values This type of signal is called the logic signal.  Because these two values ​​(or status) can be called “true” and “false”. Normally the positive power supply voltage is + Vs instead of true, and 0V represents false.

Obvious advantages of a digital signal, we can get rid of the interference signal easily. It is convenient to distinguish the desired signal. Which it has a specific value.

For example, If the logic signal means + 5V (True) or 0V (False) .. noise is as high as 2.5V. We can cut it out. We can isolate all voltages above 2.5V, is True and the voltage less than 2.5V are False.

Pros of Digital Signals

  • Digital data can be easily compressed.
  • Any information in the digital form can be encrypted.
  • Equipment that uses digital signals is more common and less expensive.
  • Digital signal makes running instruments free from observation errors like parallax and approximation errors.
  • A lot of editing tools are available
  • You can edit the sound without altering the original copy
  • Easy to transmit the data over networks

Cons of Digital Signals

  • Sampling may cause a loss of information.
  • A/D and D/A demand mixed-signal hardware
  • Processor speed is limited
  • Develop quantization and round-off errors
  • It requires greater bandwidth
  • Systems and processing is more complex.

Difference Between Analog and Digital

By the way, let’s compare them.

SignalContinuous signaltime separated signals
Wavessine wavessquare waves
ErrorsAnalog instruments usually have a scale that is cramped at the lower end and give considerable observational errors.Digital instruments are free from observational errors like parallax and approximation errors.
ImpedanceLowHigh order of 100 Megaohm

Sure, this may full I want to see you improve your skill. So, I recommend you to read more:
Analog VS Digitals , ,

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