Path: utzoo!telecom-request
Date: Wed, 29 May 91 00:35:49 CDT
From: "Patton M. Turner" <pturner@eng.auburn.edu>
Newsgroups: comp.dcom.telecom
Subject: Re: DTMF Decoder Chip Wanted
Message-ID: <telecom11.409.7@eecs.nwu.edu>
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> Does anyone know where to buy an inexpensive DTMF decoder chip?
> Preferable with easy interfacing capabilities.  I want to build one of
> those turn-on-anything-from-anywhere gizmos.  Thanks....

I don't know of a single chip implementation of a DTMF decoder.  Since
nobody seemed to come up with anything, I will give you my solution:
eight tone decoders in parallel (ECG part# 832).  Each decoder handles
a separate frequency, and the outputs are combined with NAND gates to
obtain the number.  The ECG tech manual includes an example of this
implementation.  If you can't obtain a copy of the data sheet on this
chip, let me know and I can mail you a copy.

Hope this helps.


Pat Turner    KB4GRZ    pturner@eng.auburn.edu