BU8874 Datasheet, PDF (1/10 Pages) Rohm – DTMF receiver for telephones

Communication ICs
DTMF receiver for telephones
BU8874 / BU8874F
The BU8874 and BU8874F are DTMF receiver ICs developed for use in telephone answering machines, and convert
16 different types of DTMF signals into 4-bit binary serial data. In addition to a compact 8-pin DIP (BU8874) package,
these receivers feature a wide dynamic range, eliminating the need for an external input amplifier. Expertise from a num-
ber of companies has been incorporated into these products to enable guard time control through a host microcontroller.
FApplications
Telephone answering machines
FFeatures
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 microcon-
troller.
5) Input pins equipped with hysteresis. (ACK pin)
6) 4.19MHz crystal resonator can be used.
7) 8-pin DIP package. (BU8874)
FBlock diagram
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