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Tuesday, 9 May 2017


Analogue Signal:

Our world is analogue, most things we relate with has infinite values. Working with electronics with deal with both digital and analogue signals. An electronics system that deals with analogue signals are referred to as analogue system.

Come to think of it what is (are) signals?
Signals are time varying quantities. That is, there values changes as time changes.
An example of such in electronics is voltage (or Current), when we talk of signal just think voltage.
Signals are passed between devices in order to send and receive information, which might be video, audio, or some sort of encoded data.

While these signals may be limited to a range of maximum and minimum values, there are still an infinite number of possible values within that range. 

Example of analogue signal are Audio and Video signal.
Analogue devices










Digital Signals
Digital signals must have a finite set of possible values. The number of values in the set can be anywhere between two and a-very-large-number-that’s-not-infinity. Most commonly digital signals will be one of two values – like either 0V or 5V. Timing graphs of these signals look like square waves.

Digital device









Analogue and Digital Circuits

Analogue Electronics

Most of the fundamental electronic components – resistorscapacitors, inductors, diodes, transistors, and operational amplifiers – are all inherently analogue. Circuits built with a combination of solely these components are usually analogue.  Analogue circuits are much more difficult to design than those which accomplish the same task digitally.
Analogue Signal







Digital Electronics

Digital circuits operate using digital, discrete signals. These circuits are usually made of a combination of transistors and logic-gates and, at higher levels, microcontrollers or other computing chips. Most processors, whether they’re big beefy processors in your computer, or tiny little microcontrollers, operate in the digital realm.


Digital circuits usually use a binary scheme for digital signalling. These systems assign two different voltages as two different logic-level – a high voltage (usually 5V, 3.3V, or 1.8V) represents one value and a low voltage (usually 0V) represents the other.
Although digital circuits are generally easier to design, they do tend to be a bit more expensive than an equally tasked analog circuit.
Digital Signal







Digital information has certain properties that distinguish it from analogue communication methods. These include
·    Synchronisation – digital communication uses specific synchronisation sequences for determining synchronisation.
·  Language – digital communications requires a language which should be possessed by both sender and receiver and should specify meaning of symbol sequences.
·  Errors – disturbances in analogue communication causes errors in actual intended communication but disturbances in digital communication does not cause errors enabling error free communication. Errors should be able to substitute, insert or delete symbols to be expressed.
· Copying – analogue communication copies are quality wise not as good as their originals while due to error free digital communication, copies can be made indefinitely.
·  Granularity – for a continuously variable analogue value to be represented in digital form there occur quantization error which is difference in actual analogue value and digital representation and this property of digital communication is known as granularity.

Further reading:
1. Digital Electronics for Science 

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