| Signal |
Analog signal is a continuous signal which represents physical measurements. |
Digital signals are discrete time signals generated by digital modulation. |
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| Waves |
Denoted by sine waves |
Denoted by square waves |
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| Representation |
Uses continuous range of values to represent information |
Uses discrete or discontinuous values to represent information |
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| Example |
Human voice in air, analog electronic devices. |
Computers, CDs, DVDs, and other digital electronic devices. |
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| Technology |
Analog technology records waveforms as they are. |
Samples analog waveforms into a limited set of numbers and records them. |
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| Data transmissions |
Subjected to deterioration by noise during transmission and write/read cycle. |
Can be noise-immune without deterioration during transmission and write/read cycle. |
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| Response to Noise |
More likely to get affected reducing accuracy |
Less affected since noise response are analog in nature |
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| Flexibility |
Analog hardware is not flexible. |
Digital hardware is flexible in implementation. |
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| Uses |
Can be used in analog devices only. Best suited for audio and video transmission. |
Best suited for Computing and digital electronics. |
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| Applications |
Thermometer |
PCs, PDAs |
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| Bandwidth |
Analog signal processing can be done in real time and consumes less bandwidth. |
There is no guarantee that digital signal processing can be done in real time and consumes more bandwidth to carry out the same information. |
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| Memory |
Stored in the form of wave signal |
Stored in the form of binary bit |
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| Power |
Analog instrument draws large power |
Digital instrument drawS only negligible power |
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| Cost |
Low cost and portable |
Cost is high and not easily portable |
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| Impedance |
Low |
High order of 100 megaohm |
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| Errors |
Analog instruments usually have a scale which is cramped at lower end and give considerable observational errors. |
Digital instruments are free from observational errors like parallax and approximation errors. |
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