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 tonepairs 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
Specification:
Recommended Dc Power Supply:5.5V
RecommendedOperating Temperature:-40ºC to +85ºC
Power Dissipation:500 mW
Maximum Operating Supply Current:9mA
