Voltage to PWM chip (similar to class D)?

John Larkin wrote:
On Sun, 01 Jun 2014 03:50:11 -0400, rickman <gnuarm@gmail.com> wrote:

On 5/31/2014 10:16 AM, Joerg wrote:

[...]

I pretty much only used the 8051 when I was allowed to decide. Clients
have used Atmels and also PICs that have lasted a long time but I don't
have production data for those products.
Yes, some MCUs live for a while, but not 20 years. I have never seen an
MCU other (than the 8051 and a few Mil/aerospace processors) that long.

One remarkable CPU is the Motorola/Freescale MC68332. It's just now going out of
production after at least 25 years.

Some of the old PICs are also still around. I haven't followed it in
detail but IIRC they were introduced in the 80's.

--
Regards, Joerg

http://www.analogconsultants.com/
 
On 6/2/2014 11:20 AM, Joerg wrote:
rickman wrote:
On 6/1/2014 11:09 AM, Joerg wrote:
rickman wrote:
On 5/31/2014 10:16 AM, Joerg wrote:

It was a cutting-edge FPGA in the mid 90's. With ASICs you can get much
more design security. The trick is to pick a foundry you trust and a
run-of-the-mills process that is used for tons of other products. By
going directly to the foundry you are cutting out one middleman (the
FPGA vendor) and thus reduce the overall risk.

I don't know what a "cutting edge" FPGA is other than a startup company.
Is that risky... yes of course.


With cutting edge I meant the latest and gratest (newest) from a major
FPGA vendor. The usual, more gates, faster.

I don't know why you can't be specific about the vendor and part. ...


As I said it was a very long time ago, I was not the designer of this
board and I tend to purge my notes and brain cells once in a while, of
stuff that I no longer need. I remember that they did get enough notice
to redesign it but then, based on production quantities, decided ASIC.

Ok, so you have a bias that FPGAs often go obsolete based on an
experience years ago that you know very little about. In reality FPGAs
are among the longest lived parts in the VLSI arena. If you continue to
believe otherwise you are only hurting yourself. This is easy to
research by looking at the earliest dates on data sheets. I have done
this and you can still buy parts that were first shipped over 10 years
ago. In the VLSI range of parts that is pretty good. Even when they go
EOL they turn the designs over to other companies that specialize in
continuing production for needs like yours. The last time I checked you
could still buy XC3000 family devices that were in use over 20 years
ago. If you need longer lived parts you won't be using VLSI.

--

Rick
 
On 6/2/2014 12:43 PM, Joerg wrote:
John Larkin wrote:
On Sun, 01 Jun 2014 03:50:11 -0400, rickman <gnuarm@gmail.com> wrote:

On 5/31/2014 10:16 AM, Joerg wrote:

[...]


I pretty much only used the 8051 when I was allowed to decide. Clients
have used Atmels and also PICs that have lasted a long time but I don't
have production data for those products.
Yes, some MCUs live for a while, but not 20 years. I have never seen an
MCU other (than the 8051 and a few Mil/aerospace processors) that long.

One remarkable CPU is the Motorola/Freescale MC68332. It's just now going out of
production after at least 25 years.


Some of the old PICs are also still around. I haven't followed it in
detail but IIRC they were introduced in the 80's.

Some? The question is if you designed a product in the 80's could you
have picked the right one?

--

Rick
 
rickman wrote:
On 6/2/2014 11:20 AM, Joerg wrote:
rickman wrote:
On 6/1/2014 11:09 AM, Joerg wrote:
rickman wrote:
On 5/31/2014 10:16 AM, Joerg wrote:

It was a cutting-edge FPGA in the mid 90's. With ASICs you can get
much
more design security. The trick is to pick a foundry you trust and a
run-of-the-mills process that is used for tons of other products. By
going directly to the foundry you are cutting out one middleman (the
FPGA vendor) and thus reduce the overall risk.

I don't know what a "cutting edge" FPGA is other than a startup
company.
Is that risky... yes of course.


With cutting edge I meant the latest and gratest (newest) from a major
FPGA vendor. The usual, more gates, faster.

I don't know why you can't be specific about the vendor and part. ...


As I said it was a very long time ago, I was not the designer of this
board and I tend to purge my notes and brain cells once in a while, of
stuff that I no longer need. I remember that they did get enough notice
to redesign it but then, based on production quantities, decided ASIC.

Ok, so you have a bias that FPGAs often go obsolete based on an
experience years ago that you know very little about.

It happened and I knew a lot about that at the time. As I've said
before, I don't hang onto old stuff forever. I don't have anything
against FPGA but they do go obsolete from time to time, and that wasn't
the only case. The other one I mentioned was Intel. Yeah, they have a
tendency to drop whole projects but every time this happens it hurts,
doesn't matter which vendor it was.


... In reality FPGAs
are among the longest lived parts in the VLSI arena. If you continue to
believe otherwise you are only hurting yourself. This is easy to
research by looking at the earliest dates on data sheets. I have done
this and you can still buy parts that were first shipped over 10 years
ago. In the VLSI range of parts that is pretty good. Even when they go
EOL they turn the designs over to other companies that specialize in
continuing production for needs like yours. The last time I checked you
could still buy XC3000 family devices that were in use over 20 years
ago. If you need longer lived parts you won't be using VLSI.

When I look at Digikey it's slim pickens. All zero stock except a
residual qty of 23 for a XC3090, and at a whopping $54:

http://www.digikey.com/product-search/en/integrated-circuits-ics/embedded-fpgas-field-programmable-gate-array/2556262?k=XC3000

and ... "Obsolete item; call Digi-Key for more information". Doesn't
sound too great to me.

Is Xilinx one of the better companies when it comes to parts longevity?

--
Regards, Joerg

http://www.analogconsultants.com/
 
rickman wrote:
On 6/2/2014 12:43 PM, Joerg wrote:
John Larkin wrote:
On Sun, 01 Jun 2014 03:50:11 -0400, rickman <gnuarm@gmail.com> wrote:

On 5/31/2014 10:16 AM, Joerg wrote:

[...]


I pretty much only used the 8051 when I was allowed to decide. Clients
have used Atmels and also PICs that have lasted a long time but I
don't
have production data for those products.
Yes, some MCUs live for a while, but not 20 years. I have never
seen an
MCU other (than the 8051 and a few Mil/aerospace processors) that long.

One remarkable CPU is the Motorola/Freescale MC68332. It's just now
going out of
production after at least 25 years.


Some of the old PICs are also still around. I haven't followed it in
detail but IIRC they were introduced in the 80's.

Some? The question is if you designed a product in the 80's could you
have picked the right one?

That's always the $64,000 question. Mostly I go by distributor stock
quantities which has worked well over the years or by now decades.
Sometimes I look who else uses a chip. And yeah, that includes taking a
peek at things such as pellet stoves since I have to take it apart for
maintenance once a year anyhow (or whenever the dreaded auger jam occurs).

This is, for example, how I picked a 89C51 about 20 years ago. And sure
enough you can still buy those on almost every street corner. This
design is still in production.

--
Regards, Joerg

http://www.analogconsultants.com/
 
On Mon, 02 Jun 2014 16:09:02 -0400, rickman <gnuarm@gmail.com> wrote:

On 6/2/2014 11:20 AM, Joerg wrote:
rickman wrote:
On 6/1/2014 11:09 AM, Joerg wrote:
rickman wrote:
On 5/31/2014 10:16 AM, Joerg wrote:

It was a cutting-edge FPGA in the mid 90's. With ASICs you can get much
more design security. The trick is to pick a foundry you trust and a
run-of-the-mills process that is used for tons of other products. By
going directly to the foundry you are cutting out one middleman (the
FPGA vendor) and thus reduce the overall risk.

I don't know what a "cutting edge" FPGA is other than a startup company.
Is that risky... yes of course.


With cutting edge I meant the latest and gratest (newest) from a major
FPGA vendor. The usual, more gates, faster.

I don't know why you can't be specific about the vendor and part. ...


As I said it was a very long time ago, I was not the designer of this
board and I tend to purge my notes and brain cells once in a while, of
stuff that I no longer need. I remember that they did get enough notice
to redesign it but then, based on production quantities, decided ASIC.

Ok, so you have a bias that FPGAs often go obsolete based on an
experience years ago that you know very little about. In reality FPGAs
are among the longest lived parts in the VLSI arena. If you continue to
believe otherwise you are only hurting yourself. This is easy to
research by looking at the earliest dates on data sheets. I have done
this and you can still buy parts that were first shipped over 10 years
ago. In the VLSI range of parts that is pretty good. Even when they go
EOL they turn the designs over to other companies that specialize in
continuing production for needs like yours. The last time I checked you
could still buy XC3000 family devices that were in use over 20 years
ago. If you need longer lived parts you won't be using VLSI.

http://www.xilinx.com/support/documentation/customer_notices/xcn12026.pdf

It hurt us when they dumped the whole 2E family.



--

John Larkin Highland Technology, Inc

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com
 
John Larkin wrote:
On Mon, 02 Jun 2014 16:09:02 -0400, rickman <gnuarm@gmail.com> wrote:

On 6/2/2014 11:20 AM, Joerg wrote:
rickman wrote:
On 6/1/2014 11:09 AM, Joerg wrote:
rickman wrote:
On 5/31/2014 10:16 AM, Joerg wrote:
It was a cutting-edge FPGA in the mid 90's. With ASICs you can get much
more design security. The trick is to pick a foundry you trust and a
run-of-the-mills process that is used for tons of other products. By
going directly to the foundry you are cutting out one middleman (the
FPGA vendor) and thus reduce the overall risk.
I don't know what a "cutting edge" FPGA is other than a startup company.
Is that risky... yes of course.

With cutting edge I meant the latest and gratest (newest) from a major
FPGA vendor. The usual, more gates, faster.
I don't know why you can't be specific about the vendor and part. ...

As I said it was a very long time ago, I was not the designer of this
board and I tend to purge my notes and brain cells once in a while, of
stuff that I no longer need. I remember that they did get enough notice
to redesign it but then, based on production quantities, decided ASIC.
Ok, so you have a bias that FPGAs often go obsolete based on an
experience years ago that you know very little about. In reality FPGAs
are among the longest lived parts in the VLSI arena. If you continue to
believe otherwise you are only hurting yourself. This is easy to
research by looking at the earliest dates on data sheets. I have done
this and you can still buy parts that were first shipped over 10 years
ago. In the VLSI range of parts that is pretty good. Even when they go
EOL they turn the designs over to other companies that specialize in
continuing production for needs like yours. The last time I checked you
could still buy XC3000 family devices that were in use over 20 years
ago. If you need longer lived parts you won't be using VLSI.


http://www.xilinx.com/support/documentation/customer_notices/xcn12026.pdf

It hurt us when they dumped the whole 2E family.

Original release 11/15/2001, per datasheet. Didn't even make it 13
years. Ouch.

http://www.xilinx.com/support/documentation/data_sheets/ds077.pdf

--
Regards, Joerg

http://www.analogconsultants.com/
 

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