Difference Between Analog And Digital Signal

Signal is any kind of physical quantity that conveys information. This could be electric current, voltage, electromagnetic waves that are used for wireless communication, sound etc. the two categories in which signal is classified are: Digital and Analog. Analog signals are measurements of continuous waveforms that vary with time whereas Digital signals are patterns generated by sampling a stream of continuous data at regular intervals.

What Is An Analog Signal?

Analog signals are measurements of continuous waveforms that vary with time. Analog signals vary in frequency and amplitude just as the waves carrying the information continuously vary. Analog signals use a medium to transmit information. For example, an analog clock uses the position of a rotary dial to indicate the time. Analog signals as sound waves are carried through the air as a pattern of pressure waves. The variation of the pressure is used to generate a voltage output, or analog signal, which can be transmitted from one device to another such as from a microphone to a speaker. Upon receiving the electrical signal, the pattern of pressure waves is recreated to copy or analog the sound. In this method of transmitting sound, every detail of the pattern is important and slight variations cause distortion. Analog signals can be used to transmit many types of information, as the signals are a measured response to physical changes such as changes in light, sound, temperature, position, or pressure.

Analog signals have the advantage of having the potential for an infinite amount of signal resolution, and the signals have a higher density than digital signals. The signals are easier to process than digital signals and do not require as great a bandwidth. Analog signals have the disadvantage of being sensitive to even very slight variations in the signal patterns, which cause distortion of the information such as static on a TV screen or in a radio signal. Analog signals provide measurement values at any time along the waveform. Digital signals only provide measurement values at regular time intervals along the waveform. This makes the digital signal more compact, as it can be represented by fewer values. Because of these things, digitized signals (sent as wave pulses) are a more reliable way to encode and transmit information than analog signals.

What You Need To Know About Analog

• An analog signal represents a continuous wave that keeps changing over a period of time.
• An analog signal is always represented by the continuous sine wave.
• Analog signals describe the behavior of the wave with respect to amplitude, time period and phase of the signal.
• Analog uses a continuous range of values that help to represent information.
• Examples of analog signals include: Temperature sensors, human voice in air, FM radio signals, Photocells, Light sensor, Resistive touch screen and other analog electronic devices.
• Analog signal can be used in analog devices only. Best suited for audio and video transmission.
• Analog signals are more prone to distortion in response to noise.
•  Analog signals transmit data in the form of wave.
• Analog signal has a lower data transmission rates.
• The impedance of the analog signal is low.
• The analog signal bandwidth requirement is low.
• Analog signal cannot be encrypted.
• Analog signals are less adjustable for a wide range of use.
• Analog signal processing can be done in real-time.
• Analog signals are more accurate than digital signals.

What Is A Digital Signals

Digital signals are patterns generated by sampling a stream of continuous data at regular intervals. In digital signal processing, a digital signal is a representation of a physical signal that is a sampled and quantized. A digital signal is an abstraction that is discrete in time and amplitude. The signal’s value only exists at regular time intervals, since only the values of the corresponding physical signal at those sampled moments are significant for further digital processing. The digital signal is a sequence of codes drawn from a finite set of values. The digital signal may be stored processed or transmitted physically as a pulse-code modulation (PCM) signal.

Simple digital signals represent information in discrete bands of analog levels. All levels within a band of values represent the same information state. In most digital circuits, the signal can have two possible valid values, this is referred to a binary signal or logic signal. They are represented by two voltage bands: one near a reference value (typically termed as ground or zero volts) and the other a value near the supply voltage. These correspond to the values ‘’zero’’ and ‘’one’’ (or ‘’false’’ and ‘’true’’) of the Boolean domain, so at any given time a binary signal represent one binary digit (bit).

In other words, the samples or bits of data are converted to a numeric or digit value. The binary code of 1 and 0 used in computers is an example of a digital signal. The greater the number of samples or bits used, the greater the resolution of the information. The number of bits determines the dynamics range of the result. This is important in transmitting sound waves or audio signals and is one reason musicians often prefer analog vinyl records to digital formats. Digital signals are transmitted as pulses of either on or off which transfers the data to either as 1 for on or a 0 for off. 

In a digital signal, the physical quantity representing the information may be a variable electric current or voltage, the intensity, phase or polarization of an optical or other electromagnetic field, acoustic pressure, the magnetization of a magnetic storage media etc. Digital signal are used in all digital electronics, notably computing equipment and data transmission.

What You Need To know About Digital Signal

• A digital signal represents a non-continuous wave that carries binary data and has discrete values.
• A digital signal is represented by square waves.
• Digital signals describe the behavior of the signal with respect to the rate of a bit as well as bit interval.
• Digital signal uses discrete 0 and 1 to represent information.
• Examples of digital signals include: computer, CDs, digital pens, digital phones, DVDs and other digital electronic devices etc.
• Best suited for computing and digital electronics.
• Digital signal can be noise resistant throughout transmission devoid of any deterioration.
• A digital signal transmits the data in the binary form i.e in the form of bits.
• Digital signal has a higher data transmission rate.
• Impedance of digital signal is high.
• Digital signal bandwidth requirement is high.
• Digital signal can be encrypted.
• Digital signals are more adjustable for a wide range of use.
• There is no guarantee that digital signal can be done in real-time.
• Digital signals are less accurate.

Also Read: Difference Between Analog And Digital Computer

Difference Between Analogue And Digital Signal In Tabular Form