MT8870DS1 is a complete DTMF receiver integrating both the band split 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. Applications include receiver systems for British telecom (BT) or CEPT spec (MT8870D-1), paging systems, repeater systems/mobile radio, credit card systems, remote control, personal computers, and telephone answering machines.