L3240 Datasheet PDF | STMicroelectronics

STMicroelectronics L3240

L3240 is a monolithic integrated circuit designed to replace the mechanical bell in telephone sets, in connectionwith an electro acoustical converter. The device can drive either directly a piezo ceramic converter (buzzer) or a small loudspeaker. The two tone frequencies generated are switched by an internal oscillator in a fast sequenceand made audible across output amplifiers in the transducer ; both tone frequencies and the switching frequency can be externally adjusted.

Part No.	L3240
Datasheet	L3240 Download
Manufacturer	STMicroelectronics
Description	ELETRONIC TWO-TONE RINGER
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DESCRIPTION

In this case a transformer is needed. The supply voltage is obtained from the AC ring signal and the circuit is designed so that noise on the line or variations of the ringing signal cannot affect the correct operation of the devices. The output bridge configuration allows to use a high impedance transducer with acoustical results much better than in a single ended configuration. The two outputs can also be connected independently to different converters or actuators (acoustical, opto, logic). June 1993 PIN CONNECTION ( top view) 1/6 L3240 BLOCK DIAGRAM

ABSOLUTE MAXIMUM RATINGS

Symbol VAB VAB DC Top Tstg Parameter Calling Voltage (f = 50 Hz) Continuous Calling Voltage (f = 50 Hz) 5s N/10s OFF Supply Current Operating Temperature Storage and Junction Temperature Value 120 200 30 – 20, + 70 – 65, + 150 Unit VRMS VRMS mA o C o C THERMAL DATA Symbol Rth j-amb Parameter Thermal Resistance Junction-ambient Max. Value 100 Unit o C/W

ELECTRICAL CHARACTERISTICS

(Tamb = 25oC ; VS = a...