MT8889C

MT8889C/MT8889C-1 ® Integrated DTMF Transceiver with Adaptive Micro Interface Features Central office quality DTMF transmitter/ receiver Low power consumption High speed adaptive micro interface Adjustable guard time Automatic tone burst mode Call progress tone detection to -30dBm ISSUE 2 May 1995 Ordering Information MT8889CE/CE-1 20 Pin Plastic DIP MT8889CC/CC-1 20 Pin Ceramic DIP MT8889CS/CS-1 20 Pin SOIC MT8889CN/CN-1 24 Pin SSOP -40°C to +85°C Applications Credit card systems Paging systems Repeater systems/mobile radio Interconnect dialers Personal computers The receiver section is based upon the industry standard MT8870 DTMF receiver while 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. The MT8889C utilizes an adaptive micro interface, which allows the device to be connected to a number of popular microcontrollers with minimal external logic. The MT8889C-1 is functionally identical to the MT8889C except the receiver is enhanced to accept lower level signals, and also has a specified low signal rejection level. Description The MT8889C is a monolithic DTMF transceiver with call progress filter. It is fabricated in CMOS technology offering low power consumption and high reliability. TO...