PDF datasheet covering the MT8880C, an integrated DTMF transceiver with a microprocessor bus interface, able both to decode and to generate dual-tone signalling. The document normally lists pin functions, control and status registers, timing diagrams and typical circuits with a 3.579545 MHz colour-burst crystal. It is useful when fault-finding telephone interfaces, remote-control diallers or radio signalling boards. Check the part marking and package type on the board, since DIP, SOIC and PLCC versions differ in pin count.
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