Xecom makes a certified part the XE0068

> -----Original Message-----
> From: Dave VanHorn [mailto:dvanhorn@CEDAR.NET]
> Sent: Friday, November 19, 1999 8:48 AM
> To: PICLIST@MITVMA.MIT.EDU
> Subject: Re: Telephonic Interface to DTMF Transmitter
>
>
> >    - which telephone line should I connect it to
> >    - can it be connected directly (i.e. are there chances
> of any damage
> >      to the chip because of the high voltage)
>
> You need to implement a line interface. You can't connect
> directly to the
> phone line in any real sense.  Do a web search on DAA   At
> least one company
> makes part 68 certed  DAAs that you can buy, and save yourself some
> trouble..
>
> You can do some horrible hardware hack and it will kinda
> work, and you'll
> kinda screw up the line impedance, and kinda get the levels and twist
> wrong...  I've designed several DAAs, but it's a bit more
> than an email's
> worth.
>