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'[EE] 24-bit quadrature counter chips?'
2006\10\20@115305 by Mike Hord

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Does anyone know of a dual-axis 24-bit quadrature counter
other than the LS7266R1?  LSI has been stop-shipped on
the above for several months.

Pin-for-pin with the above is best, but might be negotiable.

Mike H.

2006\10\20@122613 by Bob Axtell

face picon face
Mike Hord wrote:
> Does anyone know of a dual-axis 24-bit quadrature counter
> other than the LS7266R1?  LSI has been stop-shipped on
> the above for several months.
>
> Pin-for-pin with the above is best, but might be negotiable.
>
> Mike H.
>  
There really isn't much of a market for this kind of chip anymore.

If the speed is below 100K, the  20Mhz  PICs work good for quad tach chores.
You can pump out the values as parallel nibbles or as serial. Ubicom
chips would
work even better, and could easily handle a 2Mhz speed.

In my personal experience, tach volume controls can be spun as fast as
the human hand
can force it, and even a 4Mhz PIC can keep up by interrupt.

--Bob


2006\10\20@130145 by Mike Hord

picon face
> There really isn't much of a market for this kind of chip anymore.
>
> If the speed is below 100K, the  20Mhz  PICs work good for quad tach chores.
> You can pump out the values as parallel nibbles or as serial. Ubicom
> chips would
> work even better, and could easily handle a 2Mhz speed.

Not sure what the speed is, but it's bound to be pretty high, since this is
an industrial application, not a human input.

Eesh.  Avago has one, but the pinout is different.  Why do they do that?
Is there some kind of copyright law which prevents company A from
releasing a pin-for-pin compatible version of company B's chip with better
specs?

I know I've seen it done, sometimes.  But frequently, not.

A company could make an absolute KILLING as a second source for
pin compatible Maxim parts.  ;-)

Mike H.

2006\10\23@005044 by Herbert Graf

flavicon
face
On Fri, 2006-10-20 at 11:58 -0500, Mike Hord wrote:
> > There really isn't much of a market for this kind of chip anymore.
> >
> > If the speed is below 100K, the  20Mhz  PICs work good for quad tach chores.
> > You can pump out the values as parallel nibbles or as serial. Ubicom
> > chips would
> > work even better, and could easily handle a 2Mhz speed.
>
> Not sure what the speed is, but it's bound to be pretty high, since this is
> an industrial application, not a human input.

What about a CPLD? Many types available, in many types of packages,
perhaps you can find one that would mirror the pinout you need?

TTYL

2006\10\23@154813 by Mike Hord

picon face
I've snooped a little bit, but the power and ground pins are in a VERY
odd place (pins 3 and 10, IIRC), and it's an SOIC-28 chip, which
doesn't have a lot of CPLD options.

I may have found a source.  Otherwise, we're just out of luck.

On 10/22/06, Herbert Graf <spam_OUTmailinglist3TakeThisOuTspamfarcite.net> wrote:
{Quote hidden}

> -

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