MT8870D: DTMF - receiver, complete with filter unit and decoder unit, translates all '6 DTMF sound sequences in 4-bit code. Power-down mode, inhibit mode, amplification of the input voltage adjustable. MT8880C: DTMF transceiver, such as the MT8870 with additional transmiter unit which consist of a switched-capacitor D/A converter and a DTMF output, microprocessor-compatible 4-bit data bus for input/output.
