LS1240A

The LS1240 integrated circuit can operate in parallel with 4 devices due to its low current consumption.

The LS1240 integrated circuit is designed to replace the mechanical bell in telephone sets and is used in connection with an electro-acoustical converter. It can directly drive a piezoceramic converter (buzzer) or a dynamic loudspeaker. The output current capability of LS1240 is higher than a standard ringer, and it can drive a dynamic loudspeaker by using a decoupling capacitor, eliminating the need for a transformer. The LS1240 allows for the adjustment of tone and switching frequencies by external components and has integrated voltage and current hysteresis. Additionally, it has low current consumption to enable the parallel operation of four devices. The circuit is designed to be powered by the AC ring signal, ensuring that noise on the line or variations of the ringing signal do not affect its operation.

The tone and switching frequencies of the LS1240 can be externally adjusted by external components. The two tone frequencies generated are switched by an internal oscillator in a fast sequence and can be made audible across an output amplifier in the loudspeaker. Both tone frequencies and the switching frequency can be externally adjusted.