Description
The MT88L85 is a monolithic DTMF transceiver with call progress filter. It is fabricated in CMOS technology offering low power consumption and high reliability.
The receiver section is based upon the industry standard MT8870 DTMF receiver. The transmitter utilizes a switched capacitor D/A converter for low distortion, high accuracy DTMF signalling. Internal counters provide a burst mode such that tone bursts can be transmitted with precise timing. A call progress filter can be selected allowing a microprocessor to analyze call progress tones.

FEATUREs
• Complete DTMF transmitter/receiver
• Low voltage operation (2.7-3.6 V)
• Adaptive micro interface enables compatibility with Intel and Motorola processors
• DTMF transmitter/receiver power-down via register control or power-down pin
• Adjustable guard time
• Automatic tone burst mode
• Call progress tone detection to -30 dBm

APPLICATIONs
• Credit card systems
• Paging systems
• Repeater systems/mobile radio
• Interconnect dialers
• Pay phones
• Remote monitor/Control systems