LS1240A

LINEAR INTEGRATED CIRCUIT

UNISONICTECHNOLOGIESCO.,LTD

5 of 5

www.unisonic.com.tw

QW-R108-002.I

TYPICAL APPLICATION CIRCUIT

No current limitation is provided on the output stage of UTC LS1240A, so a minimum load DC of 50 ohms is

advised.

The two tone frequencies generated are switched by an 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 signal and the circuit is designed so that noise on the line or variations of the ringing signal cannot

affect correct operation of the device.

U T C assum es no responsibility for equipm ent failures that result from using products at v alues that

ex ceed, ev en m om entarily, rated v alues (such as m ax im um ratings, operating condition ranges, or

other param eters) listed in products specifications of any and all U T C products described or contained

herein. U T C products are not designed for use in life support appliances, dev ices or system s where

m alfunction of these products can be reasonably ex pected to result in personal injury. R eproduction in

whole or in part is prohibited without the prior written consent of the copyright owner. T he inform ation

presented in this docum ent does not form part of any quotation or contract, is believ ed to be accurate

and reliable and m ay be changed without notice.