U4076B

· 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

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 U4076B with the dc supply voltage, being developed for large operating range. The integrated circuit is overload protected.