LS1240A

LINEAR INTEGRATED CIRCUIT

UNISONICTECHNOLOGIESCO.,LTD

5 of 5

www.unisonic.com.tw

QW-R108-002.J

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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.

UTC assumes no responsibility for equipment failures that result from using products at values that

exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or

other parameters) listed in products specifications of any and all UTC products described or contained

herein. UTC products are not designed for use in life support appliances, devices or systems where

malfunction of these products can be reasonably expected to result in personal injury. Reproduction in

whole or in part is prohibited without the prior written consent of the copyright owner. The information

presented in this document does not form part of any quotation or contract, is believed to be accurate

and reliable and may be changed without notice.