Digital Signals
- [Analog Signals and Digital Signals - Javatpoint]
- Digital Signals and Digital Devices
A digital signal is a signal that represents data as a sequence of discrete values. A digital signal can only take on one value from a finite set of possible values at a given time. For digital signals, the physical quantity representing information can be many things:
- Variable current or voltage
- The phase or polarization of the electromagnetic field
- Sound pressure
- The magnetization of a magnetic storage media
Digital signals are used in all digital electronics, including computing equipment and data transmission equipment.
When plotted on a voltage versus time graph, a digital signal is one of two values, usually between 0V and VCC (usually 1.8V, 3.3V, or 5V).
Digital circuits implement components such as logic gates or more complex digital ICs. Such ICs are represented by a rectangle with pins extending from it.
- Advantages of Digital Signals
Digital communication has many advantages over analog communication as signals are digitized. Advantages to using digital signals, including digital signal processing (DSP) and communication systems, include the following:
- Digital signals can convey information with less noise, distortion, and interference.
- Digital circuits can be reproduced easily in mass quantities at comparatively low costs.
- Digital signal processing is more flexible because DSP operations can be altered using digitally programmable systems.
- Digital signal processing is more secure because digital information can be easily encrypted and compressed.
- Digital systems are more accurate, and the probability of error occurrence can be reduced by employing error detection and correction codes.
- Digital signals can be easily stored on any magnetic media or optical media using semiconductor chips.
- Digital signals can be transmitted over long distances.
- Disadvantages of Digital Signals
Disadvantages to using digital signals, including digital signal processing (DSP) and communication systems, include the following:
- A higher bandwidth is required for digital communication when compared to analog transmission of the same information.
- DSP processes the signal at high speeds, and comprises more top internal hardware resources. This results in higher power dissipation compared to analog signal processing, which includes passive components that consume less energy.
- Digital systems and processing are typically more complex.
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- The Uses of Digital Signals
Traditional audio and communication systems used analog signals. However, with advances in silicon process technologies, digital signal processing capabilities, encoding algorithms, and encryption requirements - in addition to increases in bandwidth efficiencies - many of these systems have become digital.
They are still some applications where analog signals have legacy use or benefits. Most systems that interface to real-world signals (such as sound, light, temperature, and pressure) use an analog interface to capture or transmit the information.
A few analog signal applications are listed below:
- Audio recording and reproduction
- Temperature sensors
- Image sensors
- Radio signals
- Telephones
- Control systems
Although many original communication systems used analog signaling (telephones), recent technologies use digital signals because of their advantages with noise immunity, encryption, bandwidth efficiency, and the ability to use repeaters for long-distance transmission. A few digital signal applications are listed below:
- Communication systems (broadband, cellular)
- Networking and data communications
- Digital interfaces for programmability
[More to come ...]
