Op-amp design: Bipolar or Cmos

Anyone making 4000-series CMOS anymore? If they are do they do foundry work? I'm talking _practical_ here not theoretical.

For a high voltage OpAmp in bipolar (or CMOS for that matter), features sizes and chip dimensions get enormous!

If you've got the bucks I can give you anything you want ;-)

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
         America: Land of the Free, Because of the Brave
Reply to
Jim Thompson
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I just completed another laser circuit design. Lotsa CD4000 in there and it worketh :-)))

I bet Supertex' foundry could build a CMOS opamp design with a few dozen volts VCC. Of course it'll be big, but ain't everything bigger in America anyway?

--
Regards, Joerg

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

I don't care, I got silicon to burn (3000x3000 sq.um). I saw a lm358 compatible design with 1600x800. I might just scale up the 800x800 design and see what happen.

Problem is I don't have much up-front bucks, but back-end license bucks are possible. The customer would pay whatever we ask, if the chip works. This will either be my first or last chip, depends on how it turns out.

Reply to
linnix

To use Supertex as a foundry will cost you dearly.

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
         America: Land of the Free, Because of the Brave
Reply to
Jim Thompson

If this is a serious project we should talk, so that you make what you _actually_ need rather than what you _think_ you need.

Wait until the last week of June or later... I'm up to my eyeballs in work right now.

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
         America: Land of the Free, Because of the Brave
Reply to
Jim Thompson

The customer is serious enough to start prototyping (3000 at a time).

OK, will check with you later. I am also busy with the bottom wafer anyway.

Reply to
linnix

I know. Designing ultrasound machines for over 20 years now ;-)

Do you know what became of Telmos back in the good old days? They had some really nice HV capabilities.

--
Regards, Joerg

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

AT&T had a HV, like 400 volts, cmos line. They used to fab some of the Apex hv opamps. DC specs were bad, and noise was horrendous. Interestingly, some of the Apex amps are now just parts on small boards.

John

Reply to
John Larkin

"Jim Thompson" wrote in message news: snipped-for-privacy@4ax.com...

Doesn't AMI still run High Voltage CMOS Processes?

Yes, it seems they do.

formatting link

They claim up to 100V on 0.7um CMOS.

And they claim a "cost sensitive" C5X Process at 0.5um with 20V Supplies.

Robert

Reply to
Robert

What? Didn't the profession redesign the 1970's Fairchild (CMOCFairchild) to come out with the weekly new integrated wonder of which the 700 series are still with us. It was fun to be in electronics then.

Stanislaw

Reply to
Stanislaw Flatto
[snip]

Yep, that's worth a look-see. But Linnix was saying "3000", which isn't exactly high volume. Maybe a MOSIS run?

I only seem to get to Pocatello in the winter :-(

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
         America: Land of the Free, Because of the Brave
Reply to
Jim Thompson

MOSIS run is 10,000.

3000 is for the MEMS Multi-Masks prototype run. The Analog prototype/ production costs are more expensive. That's why we are doing it in two phases: first getting the MEMS to work, then integrating the analog circuits.

Reply to
linnix

Except for Telmos back in the old days I somehow kept ending up with automotive but that worked. Not opamps, this was custom muxes with our own amps plus pulsers and some logic on there. The kicker was a 64 to 16 mux where the design was a bit of a white-knuckle ride. Then they came and bingo, worked right out of the box. That night we all went out to a pub ;-)

--
Regards, Joerg

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

It still is fun! Or actually more fun than ever because now we have places like Digikey.

--
Regards, Joerg

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

I always liked AMI, never been disappointed. They did some tough chips for us. So yes, Idaho does produced something other than potatoes. If it just wasn't so freaking cold up there.

--
Regards, Joerg

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

And cheap PCB proto houses.

robert

Reply to
Robert Latest

Friend of mine built this:

formatting link

May give you details on how to design your op-amp.

JB

Reply to
jackbauer

Thanks Jim, for the slow learners : The voltages defines the insulation thickness, and a thicker insulation is to be compensated with area to get the same capacitance. Since the insulation thickness is linear to the voltage, as the area is to the capacitance, IMO, the area should scale linear with the voltage. Meaning double the voltage, and the area is also doubled.

Sounds reasonable. No ?

Rene

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Ing.Buero R.Tschaggelar - http://www.ibrtses.com
& commercial newsgroups - http://www.talkto.net
Reply to
Rene Tschaggelar

I'm not quite sure about the ratio, but...

In CMOS, thicker "insulation" as in gate oxide equates to more device area to get the same transconductance. Also the drain-source spacing must increase to prevent punch-through.

In bipolar, the epitaxial thickness goes up linearly with voltage, but isolation diffusion horizontal spread during the vertical diffusion increases area as well. Base to isolation dimension must increase linearly with voltage, etc.

I'm guessing it's at least a "square" function for both process types :-(

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
         America: Land of the Free, Because of the Brave
Reply to
Jim Thompson

Without saying too much to break my NDA with the fab, the target voltage is 15V. So, no point in going more than 18V to 20V.

By the way, what's the best way to make 5 to 10pF capacitors?

Reply to
linnix

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