TS2418 Datasheet, PDF (3/4 Pages) Taiwan Semiconductor Company, Ltd – Telephone tone ringer with bridge diode

Test and Application Circuit
.
Description:
The TS2418 tone ringer derives its power supply by rectifying the AC ringing signal. It uses this power to activate two
tone generators. The two tone frequencies generated are switched by internal oscillator in a fast sequence and made
audible across an output amplifier in the loudspeaker; both tone frequencies and the switching frequency can be
externally adjusted.
The device can drive either directly a piezo ceramic converter (buzzer) or small loudspeaker. In case of using a
loud-speaker, a transformer is needed.
An internal shunt voltage regulator provides DC voltage to the output stage, low frequency oscillator, and high f
frequency oscillator. To protect the IC from telephone line transients, a zener Diode is included.
TS2418
3-4
2004/09 rev. A