MT8870DE

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.

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