DTMF Reciever MT8870

The MT8870DE is a complete DTMF receiver integrating both the band-split filter and digital decoder functions. The filter section uses switched capacitor techniques or 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. Features • Complete DTMF Receiver • Low power consumption • Internal gain setting amplifier • Adjustable guard time • Central office quality • Power-down mode • Inhibit mode • Backward compatible with MT8870C/MT8870C-1 Applications • Receiver system for British Telecom (BT) or CEPT Spec (MT8870D-1) • Paging systems • Repeater systems/mobile radio • Credit card systems • Remote control • Personal computers • Telephone answering machine Component Datasheet MT8870 Datasheet