The MT8888C is a monolithic DTMF transceiver with
call progress filter. It is fabricated in CMOS
technology offering low power consumption and high
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 MT8888C utilizes an Intel micro interface, which
allows the device to be connected to a number of
popular microcontrollers with minimal external logic.
The MT8888C-1 is functionally identical to the
MT8888C except the receiver is enhanced to accept
lower level signals, and also has a specified low
signal rejection level.