The MT8870D/MT8870D-1 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. October 2006 Ordering Information Jul 25, 2008 · one more circuit: DTMF decoder interface for designing Caller ID Unit. It's very simple circuit using DTMF decoder MT8870 (or CM8870). As shown in the circuit, u'll receive an interrupt ( if NAND output is connected to INT of the microcontroller) whenever u receive a call or make a call and then u can use yr program to read the digits coming out of pin 11 to 14 of the MT8870. ISO2-CMOS Integrated DTMF Receiver, MT8870 datasheet, MT8870 circuit, MT8870 data sheet : MITEL, alldatasheet, datasheet, Datasheet search site for Electronic Components and Semiconductors, integrated circuits, diodes, triacs, and other semiconductors.