interfacing telephone line with MT8870

[sumeshm.pnr]

what r the mail thing i have to notice while connecting telephone line with DTMF ic(MT8870).... can i directly connect line with MT8870?? do i need to do any adjustment in that??..

 

[Sceadwian]

What do you mean mail things? You're not supposed to connect anything directly to a telephone line, it's illegal in the US it may be so in other countries as well.
http://www.electro-tech-online.com/custompdfs/2009/03/CI-2-DTMF.pdf
Shows one method of interfacing an MT8870 to a phone line. The capacitors are for isolation and the zeners are to shunt any voltage spikes.