[sci.electronics] ? Touch Tone Decoder IC

flloyd@L1-A.West.Sun.COM (Fred Lloyd SUN Phoenix SE 602-275-5537 x17) (04/23/91)

Can anyone recommend a good Touch Tone Decoder IC?  I'd like to decode
all 16 tones with a 4 bit output and strobe.  I'd like a cheap solution
with minimum parts count. 

Thanks in advance - 

-fred


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| Fred Lloyd  AA7BQ                        Fred.Lloyd@West.sun.com |
| Sun Microsystems, Inc.                             ...sun!flloyd |
| Phoenix, AZ       (reality -- what a concept!)    (602) 275-4242 |

sp@questor.wimsey.bc.ca (Steve Pershing) (04/25/91)

flloyd@L1-A.West.Sun.COM (Fred Lloyd SUN Phoenix SE 602-275-5537 x17) writes:

> Can anyone recommend a good Touch Tone Decoder IC?  I'd like to decode
> all 16 tones with a 4 bit output and strobe.  I'd like a cheap solution
> with minimum parts count. 

Check out Sierra Semiconductor's SC11202/sc11203/sc11204 DTMF receivers. 
They all take a standard TV color-burst crystal (3.58Mhz) and are
available in DIP and SOIC packages.

Sierra is in San Jose at 2075 N. Capitol Avenue, 95132, tel: 408 263 9300,
and has a Fax at 408 263 3337.

Hope that helps.


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whinery@hale.ifa.hawaii.edu (Alan Whinery) (04/25/91)

In article <1629@west.West.Sun.COM> flloyd@L1-A.West.Sun.COM (Fred Lloyd SUN Phoenix SE 602-275-5537 x17) writes:
>Can anyone recommend a good Touch Tone Decoder IC? 

I have only ever seen two -- the SSI201P and SSI202P, which are made
by Silicon Systems, Inc.. The specs are easy to come by, but I don't
know of any suppliers. Radio Shack showcased the 201 a couple of 
years ago, but no longer sells them.

Alan
whinery@hale.ifa.hawaii.edu


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dcl@gvgspd.GVG.TEK.COM (D.C. Ladner) (04/26/91)

In article <1629@west.West.Sun.COM> flloyd@L1-A.West.Sun.COM (Fred Lloyd SUN Phoenix SE 602-275-5537 x17) writes:
>Can anyone recommend a good Touch Tone Decoder IC?  I'd like to decode
>all 16 tones with a 4 bit output and strobe.  I'd like a cheap solution
>with minimum parts count. 

  Try OKI Semiconductor MSM6920RS or 6945 .... Single chip solution.

~dcl

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Ed_Meyer@mindlink.bc.ca (Ed Meyer) (04/26/91)

In addition to the offering by Sierra and Motorola, there is also a company
called Teltone (or very close to that spelling) which, if memory serves, also
offer DTMF encoder/decoder ICs.

        Ed Meyer

cyborg@kauri.vuw.ac.nz (Alex Ivopol) (04/27/91)

flloyd@L1-A.West.Sun.COM (Fred Lloyd SUN Phoenix SE 602-275-5537 x17) writes:

> Can anyone recommend a good Touch Tone Decoder IC?  I'd like to decode
> all 16 tones with a 4 bit output and strobe.  I'd like a cheap solution
> with minimum parts count. 

Check out the MC145436 (Motorola). It has 4 bit output with strobe, decodes
all 16 tones, outputs can be placed into high impedance mode.

From memory, the only external components are a 3.579545Mhz Xtal in parallel
with a 1Mohm resistor. It provides an output clock for chaining several such
devices from a single Xtal. Maximum supply voltage is 6v. I got the data sheet
somewhere around here so if anyone is interested I can mail more info...
--
Alex T. IVOPOL        
cyborg@kauri.vuw.ac.nz

sp@questor.wimsey.bc.ca (Steve Pershing) (04/28/91)

Ed_Meyer@mindlink.bc.ca (Ed Meyer) writes:

> In addition to the offering by Sierra and Motorola, there is also a company
> called Teltone (or very close to that spelling) which, if memory serves, also
> offer DTMF encoder/decoder ICs.

Ed is right... (I forgot about that one!)   In case you have trouble
locating them, they are in Seattle, Wa. (or one of its many suburbs).


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    Steve Pershing, System Administrator

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 :===========================================================================:
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robf@mcs213j.cs.umr.edu (Rob Fugina) (04/29/91)

In article <1629@west.West.Sun.COM> flloyd@L1-A.West.Sun.COM (Fred Lloyd SUN Phoenix SE 602-275-5537 x17) writes:
>Can anyone recommend a good Touch Tone Decoder IC?  I'd like to decode
>all 16 tones with a 4 bit output and strobe.  I'd like a cheap solution
>with minimum parts count. 

Although I have never used the chips, I have a Teltone Electronics data
book, and it seems their M8870 is exactly what you want.  There are other
companies that make touch tone decoders that probably are pin-compatable
that include the "8870" in the device number.  The reason I haven't used
the chips is that I can't find anywhere to get ahold of one...yes, one.
The only place I've found them at all is with Active Electronics, (not the
Teltone part, but another brand), and that particular item has a $25
line-item minimum due to how they stock it.  Hope I helped a bit...

Rob  robf@cs.umr.edu