MT8870 DTMF decoder - DIP-28 IC, 5 V, 16 key codes
Pay in 30 days
Pay in 30 days
Description
Product Overview
- Decoder for dual-tone multifrequency signals from telephone keys
- Decodes DTMF tones into parallel four-digit binary codes
- Input voltage 5 V
- Outputs for key codes and control logic
- DIP-28 IC package with integrated oscillator
Product Description
The DTMF decoder converts the acoustic signals from telephone keys into digital codes and is suitable wherever voice-frequency commands need to be detected and processed. Telephone devices emit two superimposed sine tones when a key is pressed; this decoder recognizes each of the 16 possible combinations and outputs the result as a four-digit binary code.
The component filters the two frequency components of each tone, decodes them, and provides the result on four parallel outputs. An additional control signal indicates whether a valid tone has been detected. The oscillator is already integrated into the IC, so no external clock source is required. With a 5 V operating voltage, the decoder can be connected directly to microcontroller boards and standard signal-processing boards.
Applications include remote-control systems operated via telephone lines and the decoding of tone-dialing sequences in industrial systems. The decoder is also used in prototypes for voice and key return-channel applications. A classic scenario: a telephone system forwards incoming tones to the decoder, whose output code then controls a connected control module, such as a relay, or triggers an interrupt on a microcontroller.
The four output lines can be evaluated via simple digital inputs on the controlled system. Calibration is not required. A suitable audio input on the telephone system or audio device and a stable 5 V power supply for the IC are required.
Safety Notice
The component is intended exclusively for building prototypes and for testing and development purposes. Use in telephone systems that are part of a building's electrical installation is not permitted. Work on or near electrical installations must be carried out by a qualified electrician. If you have questions about integration into existing systems, consult a qualified electrician before commissioning.
Scope of Delivery
- 1x MT8870 DTMF - Audio Decoder, voice decoder module