MT8870 DTMF Dual Tone Multi Frequency Decoder

The MT8870 is a decoder that is able to distinguish key presses from most touch tone phones. This module incorporates a built-in audio jack to connect the DTMF source and also both LED and output pins for the decoded values. This is the perfect module to use if you want to add control to your project from a phone that produced DTMF signals or and other source that can produce the same signals.

The MT8870 is a complete DTMF receiver integrating both the bandsplit filter and digital decoder functions. The filter section uses switched capacitor techniques for high and low group filters; the decoder uses digital counting techniques to detect and decode all 16 DTMF tone-pairs into a 4-bit code. External component count is minimized by on chip provision of a differential input amplifier, clock oscillator and latched three-state bus interface.