MT8889C

The MT8889C 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 of MT8889C 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.