From analog technology or analog technology is called in the electrical and electronics valuable to himself and time continually changing physical parameters, particularly voltage and current . Thus, with analog technology, a signal can have an infinite number of values over time. In contrast to this, digital technology only considers discrete quantities, i.e. those that can only assume a finite, usually precisely defined number of different values. As a rule, the term analog technology is used in signal transmission and processing , but also in connection with measurement and control technology .
In many areas of technology, analog technology has largely been replaced by digital technology, although some components usually remain analog - for example, in today's fully digital mobile phones, for example, the electronics for processing the microphone and loudspeaker signals , as well as the high-frequency transmitting and receiving parts, still work analog. In such cases, where analog and digital electronics complement or mix, one speaks of hybrid electronics or mixed-signal electronics or circuits.
Typical components of analog technology are amplifiers , filters , rectifiers , mixers , etc. In contrast, there are components of digital technology such as logic gates , microprocessors and data memories .
Since people can only process sounds and images in analog form, but digital technology causes less interference in storage and transmission over long distances, both technologies are now combined. The signals from both technologies can be converted into one another with analog-to-digital converters or digital-to-analog converters .
One of the advantages of analog technology is that it uses the simplest and often very few electronic components, such as B. resistors, coils and capacitors can be realized. The susceptibility to interference and the distortion of the signals, which occur on the one hand due to internal physical properties of the components and lines and on the other hand due to capacitive and / or inductive coupling between different components, have a disadvantageous effect .
Due to the high degree of integrability of the components (more components and functions per area) and the sometimes lower energy consumption, digital technology is taking on more and more tasks and is increasingly displacing analog technology. However, for special industrial applications, for example in the automotive sector or in the aerospace industry, analog and mixed circuits are still used; however, mostly reduced in size and converted into integrated circuits .
Gradual replacement of analog by digital technology
The differences between the old analog and modern digital technology for records and telephones become very clear . Until the 1980s, the devices were all built using analog technology and were known for distortion, crackling impulses and a limited frequency range (“telephone voice”). Since around 1983 the record has been gradually replaced by the practically noise-free CD , and all today's DECT telephones and cell phones also transmit voice digitally. In these devices, the signal processing between the antenna and A / D or digital-to-analog converters is carried out by analog or mixed-signal circuits. While the introduction of digital radio is relatively slow, the switch to digital television is in full swing, analogue television reception via antenna in Germany has been replaced by digital DVB-T , and analogue channels are increasingly being replaced by digital ones in cable networks . Likewise, the previously common analog video recorders with cassettes have been replaced by various digital technologies, such as the hard disk recorder (also: PVR) and the recordable DVD . The analog audio cassettes , which used to be very widespread , have now also been replaced, initially by the recordable CD-R , now mainly by digital MP3 technology.
Areas of application
- Radio ( VHF , MW , LW ) and also terrestrial television (currently partially switching to digital technology)
- Telephone (with analog connections between the exchange and terminal device . Some digital telephones only convert the digital signal back into audible analog signals in the receiver)
- HiFi - Amplifier (signal transmission between tape, CD and DVD players, digital already partly over fiber optics )
- Analog TVs and CRT monitors
- Classic impulse technology
- Manfred Seifart: Analog circuits . 6th edition. Verlag Technik, 2003, ISBN 978-3-341-01298-7 .