BU8874 - DTMF receiver for telephones
203 Communication ICs FInput / output circuits INPUT PWDN BU8874 / BU8874F OSC ACK SD ESt 204 Communication ICs FElectrical characteristics (unless otherwise noted, Ta=25_C, VDD=5.0V) BU8874 / BU8874F 205 Communication ICs FCircuit operation (1) An overview of operation A DTMF signal is
BU8874 Features
* 1) Dynamic range of 45dB. (internal AGC) 2) Power down mode. 3) 4-bit binary serial data output. 4) Guard time can be controlled through host microcontroller. 5) Input pins equipped with hysteresis. (ACK pin) FBlock diagram 6) 4.19MHz crystal resonator can be used. 7) 8-pin DIP package. (BU8874) 2