DTMF (Dual Tone Multi-Frequency) decoders are devices that receive data transmissions in amateur radio frequency bands. They constantly monitor incoming signals for valid DTMF digits. These electronic circuits decode DTMF dial tones from telephone lines into touch-tone phones via a process known as tone dialing.
The basic DTMF decoder identifies tones from a normal touch-tone phone. It then activates an LED to provide a 4-bit binary signal as an output code.
DTMF decoders are tolerant of level variations, but function optimally at a 0dB range.
What are DTMF decoders used for?
DTMF decoders increase connectivity in electronics to allow better control of applications. Home applications like alarm systems, electronic gates and garage doors, intercom systems and everyday appliances make use of DTMF functionalities.
Public switched telephone networks (PSTN) and voice response systems are other examples where DTMF application is necessary.
Types of DTMF decoders
The most common types of DTMF Decoders include 2-tone, 5-tone, multi-tone and burst-tone versions. Multi-tone decoders receive and translate multiple tones from the source, and burst-tone versions decode clashing frequencies into binary signals
