Description

The three-tone ringing integrated circuit U4076B, in conjunction with a piezo transducer or loudspeaker replaces the normal electromechanical telephone bell. It is operated with the ringing current from the exchange. There is also a possibility of operating the IC with the dc supply voltage, being developed for large operating range. The integrated circuit is overload protected.

Features

● Three-tone ringing sequence with 800 Hz, 1067 Hz and 1333 Hz

● Sequence frequency adjustable between 2.5 Hz and 25 Hz

● Adjustable volume

● Push-pull output stage

● Piezo transducer or loudspeaker connection

● Common input for frequency and call recognition

● Reduced pulse duration for electromagnetic transducers

● Clock oscillator with ceramic resonator or LC series cct possible

● Input protective diode

● On-chip rectifier bridge

● Protection circuit against ringing in a parallel circuit

Benefit

● Suitable for German Post Office Specification, FTZ 121671 Pfl. 3, edition dated 24.03.82