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Voltage to PWM chip (similar to class D)?

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.

Dropping a package is all it takes. That blows your production straight out of the water.

They were wrong. Just like the guy who told me 20 years ago that CD4000 logic was on the way out.

MPW and shuttle runs have actually made the entry fees into that world lower. One of the ICs that we sucessfully designed together with an IC house had less than $200k NRE and that included my time and a nice batch of chips from a MPW run.

And then produce it almost forever. A run-of-the-mills BiCMOS process these days will get the occasional additional module (such as higher-voltage capable devices on the chip) but you don't have to use it.

[...]

I do not find it difficult, I am just looking for something that has this in an IC for less real estate use. That's all.

As I said, I can easily design this in discretes and opamps. If there was a class-D modulator that has clean DC-handling I would not have to and can save real estate on the board.

You can use a faster 8051 but yes, if you need more performance the ARM is the way to go. Or even Atom. That will probably happen for me this year.

I do a lot of very unorthodox designs with their chips. I prefer them for two reasons:

a. LTSpice models.

b. Longevity in the supply chain.

Yes, they have.

You are probably thinking of ASIC in their old definition from the 80's or so where the digital ones were in essence like gate array. Nowadays you can have tons of analog standard funtions and they get scaled to your needs. You can also design your own blocks. BTDT, many times. It's full custom and some of the chip design places even have ASIC in their names, like this one whioch was recently bought by Microsemi:

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All the ones I ever dealt with will design a fully tailored IC for you and, unless this is explicitly agreed upon to save NRE or whatever, it will not be shared with any other customer of theirs.

[...]

Well, no digital jar on this one unless I put it there ;-)

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Regards, Joerg 

http://www.analogconsultants.com/
Reply to
Joerg
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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.

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Regards, Joerg 

http://www.analogconsultants.com/
Reply to
Joerg

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.

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Rick
Reply to
rickman

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

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Rick
Reply to
rickman

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.

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:

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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?

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Regards, Joerg 

http://www.analogconsultants.com/
Reply to
Joerg

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.

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Regards, Joerg 

http://www.analogconsultants.com/
Reply to
Joerg

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

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John Larkin         Highland Technology, Inc 

jlarkin att highlandtechnology dott com 
http://www.highlandtechnology.com
Reply to
John Larkin

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

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Regards, Joerg 

http://www.analogconsultants.com/
Reply to
Joerg

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