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Do semiconductor datasheets suck?

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16bitanalogue:

--- Quote from: magic on November 27, 2023, 03:30:59 pm ---Include complete absolute maximum ratings.

I have seen 21st century chips whose datasheet fails to mention the existence of some clamping diodes :palm:
It's also nice if diodes are specified to survive X mA of clamping current rather than just "VCC+300mV".

--- End quote ---

10mA is my rule of thumb. And, barring typos, the ABS MAX should always have VDD+300mV. If it does not then presume there is not a clamp. Some of my datasheets are like this.

David Hess:
If block diagrams are given, then input and output circuits should be shown in detail.

The test circuits used to measure parameters should be published.

CatalinaWOW:
I don't want to have to perform sensitivity analysis to determine equations for values of associated components.  Not because it is a lot of work (though that is true too), but because I don't know if those equations will apply to the next lot I buy from you.  I don't want an analysis/redesign cycle baked into each year, or quarters new purchase order.  If you don't know how your part is intended to work I'm not sure why I would want to buy it.

Similarly, typical readings are wonderful if they really represent mean performance.  But historically that has rarely been true.  I would much rather have the pass fail test setup and conditions for your production line.  And yes I know that treads pretty heavily on the competitive information line.  But it is what I really need to do a proper design, and could become a competitive advantage.  A way to set your company apart from the many clone vendors whose clones only match a couple of parameters.

Finally, your part is intended to solve a market problem.  That is the whole reason it exists, instead of some similar product from you or another vendor.  Your data sheet should clearly show what that purpose is, and any special conditions required to achieve it.  Even if price is that reason you should show that you achieve parameters X,Y and Z at that price point.

16bitanalogue:

--- Quote from: David Hess on November 28, 2023, 02:32:16 am ---If block diagrams are given, then input and output circuits should be shown in detail.
The test circuits used to measure parameters should be published.

--- End quote ---

Depending on the product, yes. Older op-amps TI/NatSemi used to show the transistor level design, but even this was sanitized.  More complex products that would be a negative, Ghost Rider. That ESD clamp? We show a Zener, but it's not really a Zener. It simply acts as one. We would not show the logic on how PFM mode is activated in a buck converter mode pin; there would simply be a "PFM Logic" block. It's simply too complex.



--- Quote from: CatalinaWOW on November 28, 2023, 03:08:27 am ---I don't want to have to perform sensitivity analysis to determine equations for values of associated components.  Not because it is a lot of work (though that is true too), but because I don't know if those equations will apply to the next lot I buy from you.  I don't want an analysis/redesign cycle baked into each year, or quarters new purchase order.  If you don't know how your part is intended to work I'm not sure why I would want to buy it.
--- End quote ---

This is true with any part. Do you take this approach, let's say, with an non-inverting op-amp? The signal gain is 1 + Rf/Rg ignoring non-idealities (and there are alot, even academically that are ignored), so what would not apply to the next lot into perpetuity?

This is why customer's are always directed to design to MIN/MAX in the datasheet. As I mentioned earlier, some manufacture's can send you the characterization data, but it will always be up to your design team to do their own due diligence. I spearhead that all tests completed on the ATE should show MIN, TYP, MAX in the electrical characteristics table. TYPICAL being the mean of the lot(s) at +27C. The goal being to include as much data as I can to mitigate questions.

If you will, TYP is based on initial characterization of the lot(s). Over time that can certainly shift; however, as long as new die are tested are within MIN/MAX limits set by design after review of the characterization data and there is not some large shift in the distribution after for all other production lots into perpetuity, all parts will pass.


--- Quote from: CatalinaWOW on November 28, 2023, 03:08:27 am ---Similarly, typical readings are wonderful if they really represent mean performance.  But historically that has rarely been true.  I would much rather have the pass fail test setup and conditions for your production line.  And yes I know that treads pretty heavily on the competitive information line.  But it is what I really need to do a proper design, and could become a competitive advantage.  A way to set your company apart from the many clone vendors whose clones only match a couple of parameters.
--- End quote ---

You still have +/- 6-sigma around the mean, so it would be beneficial to understand what you mean by it being "rarely true." And I have shared the characterization data with customer's before. The P/F happens to be the final test limit. The final test limit is lower than the MIN/MAX shown in the electrical characteristics table.
Given the FT and EC limits are often much wider than +/- 6-sigma if I were to provide that data to you, it is on you to review your design if you chose to tighten your system requirements below MIN/MAX.
There is a give and take here. Either design to MIN/MAX which is the 'legal' answer, or take the characterization data and complete your own analysis; a.k.a the 'engineering answer'.

Even the largest volume, strategic customers follow this philosophy. This is my very professional and cordial way of saying, "Who the hell do you think you are, buddy?"

Smokey:
Every product is different, and every use cause cannot be anticipated.  No one process will make a perfect datasheet for every product.

I've said this elsewhere, but the only path to great documentation I know of is through feedback and revision.

So give it your best shot based on what you think the user will need to know, and get that document in front of users and see what they have to say.  Then revise the document as fast as possible!

Maybe a first pass would be having some internal engineer not associated with the part production actually try to use the part in a real design. 
Then release for public.  It would be amazing to have a direct link to give datasheet feedback for that specific document.  Maybe a mechanism for checking if the datasheet revision is the newest?

Most of all, Listen to the questions your users ask about that specific part.  Monitor the web forums.  Talk to your FAE.  See what is giving people a hard time or is confusing and figure out how to add that information into the datasheet.

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