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Chip making process
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Richard Crowley:

--- Quote from: ZeroResistance on October 15, 2018, 05:24:29 pm ---Do these design kits need to be purchased from the foundry? eg. AMS
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The performance (threshold voltage, speed, current capacity, etc.) of each transistor is inextricably tied to the process parameters.  So, unless you can get something tied to the selected process, you would likely be designing from a lower level.


--- Quote ---Its interesting to hear that each transistor in an analog circuit needs to be manually crafted.
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Because a transistor of exactly the same dimensions will operate quite differently depending on what process it is made with.  And, of course that applies to ALL circuits.  There are no "digital circuits".


--- Quote ---Your would need a quite a big team to make a large circuit wouldn't it?
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Define: "large circuit"?  Do you mean 1000s of transistors or billions of transistors?
Wimberleytech:

--- Quote from: coppice on October 15, 2018, 05:28:54 pm ---
--- Quote from: ZeroResistance on October 15, 2018, 05:24:29 pm ---
--- Quote from: jmelson on October 15, 2018, 04:54:08 pm ---
Some design kits have a lot of stock modules like op-amps included, some do NOT.  You have to get the specific kit to know what will be included.
Otherwise, there are some generic circuits like op-amps that you might be able to download from people.  Well, there is no synthesis for analog parts, that's why each transistor needs to be "carved" to meet your needs.  So, the modules are just a bunch of transistors with dimensions included in them.

Jon

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Thanks for the info,
Do these design kits need to be purchased from the foundry? eg. AMS
Its interesting to hear that each transistor in an analog circuit needs to be manually crafted. Your would need a quite a big team to make a large circuit wouldn't it?

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Unless you can find a canned analogue solution that exactly suits your needs, licensable in a reasonable manner, tailored for the exact process you will use, expect your analogue development to be fairly expensive and protracted.

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Just now read through this thread.  Lots of good information and answers.

Lemme make it easy on you.  I will design your chip for you.  Send me the spec (just sketch it on a bar napkin if that is convenient) and I will get started.  Paypal is fine for billing (how well funded is your Paypal account?).
 :-DD
srce:

--- Quote from: ZeroResistance on October 15, 2018, 05:24:29 pm ---Do these design kits need to be purchased from the foundry? eg. AMS

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The PDKs are usually free - these will often include a standard cell library (e.g. basic AND/OR/NOT gates and Flip Flops) and basic IO cells as well, but not always.
jmelson:

--- Quote from: ZeroResistance on October 15, 2018, 05:24:29 pm ---
--- Quote from: jmelson on October 15, 2018, 04:54:08 pm ---
Some design kits have a lot of stock modules like op-amps included, some do NOT.  You have to get the specific kit to know what will be included.
Otherwise, there are some generic circuits like op-amps that you might be able to download from people.  Well, there is no synthesis for analog parts, that's why each transistor needs to be "carved" to meet your needs.  So, the modules are just a bunch of transistors with dimensions included in them.

Jon

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Thanks for the info,
Do these design kits need to be purchased from the foundry? eg. AMS

--- End quote ---
In general, you have to supply an NDA to MOSIS, they get it approved through the foundry and then you get the design kit, for no extra fee.  I guess that is all rolled into the price at MOSIS.

--- Quote ---Its interesting to hear that each transistor in an analog circuit needs to be manually crafted. Your would need a quite a big team to make a large circuit wouldn't it?

--- End quote ---
Well, no.  We have a professor of IC design, he has masters students, and guides them through the process.  So, we get custom chips, and they get incredible experience actually doing part of a chip design.  Usually, the prof and 2 students do the whole design, simulation, layout, etc.  You don't have to actually DRAW every feature of the transistor.  You tell the tools the size (length and width) and the design kit puts out the complicated interdigitated structure.  You then plant the transistor where you want it, and wire it up.

Still, it is VERY much slower than PC board layout, possibly 100X slower.  A prototype PC board will cost a few hundred $ and take you a week or two to build and find the errors.  The ASIC costs tens of K $, takes months to come back from the foundry, then you have to make a test board to power up the chip and see if it works.

Jon
Kjelt:
I had a "chip process"intro course two years ago, just looked through the notes, the costs are staggering.
The design (only the design) costs as rule of thumb $1/transistor, the examples given all had more than 100M transistors so I guess for lower amounts of transistors this might be much higher.
The reticles (need two per layer) you need at least 20 depending on the nr of layers, are for the lower layers around $100k/piece upto $300k/piece for state of the art tech.
Don't know what your company like to invest but this is not a game for small players.

If you want to follow the course:
 http://www.bitsonchips.com/
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