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Datasheets: Technical Treatise or Marketing Manure?

As an Engineer, I was never much on reading. I'm more visually orientated and hands on. I'd rather be sitting in a lab blowing up circuits or laying out a circuit board. However, when it came to selecting those critical components, I just couldn't help but put on my reading glasses and start going through the component datasheets. I really enjoyed the 80 page datasheets. Okay — maybe that's a slight exaggeration. I actually much preferred the half page notes on chip resistors.

I have read at least a thousand datasheets in my time, and from the first one I ever saw to number one thousand, I always ask myself if I'm benefiting from them. I mean, when datasheets are written, are they really taking into consideration the millions of possible applications? What works for you may not work for me.

Do we just look at datasheets to get a general idea of what could work? Do we use them as a comparison tool to weed out competition and save time and more quickly get to the workbench? We never really know what works until we run the parts through the ringer and properly qualify them. There are many times when I've seen parts perform differently in the reality of the application than what the datasheets claimed. Sometimes better and sometimes worse.

I do realize how important datasheets can be, but for the sake of this discussion, let's think a little deeper. Are datasheets really technical documents or are they marketing material to promote the part? Are the technical writers and marketing people that put these documents together experienced in the testing and in the real world applications? Maybe they don't need to be as they are just taking data from the test engineers and making the data look pretty on paper.

How reliable are the datasheets that many of us at times rely on 100% for our designs. I have actually met some engineers that do not ever request datasheets. They simply order the samples and go to test. I guess there are pros and cons to each method.

Is there a better tool or a document that engineers would prefer or that they would benefit more from other than these technical/marketing documents? We think that reading through the data will save us time, but what if the components you did not select based on the datasheet were actually the parts that performed the best in actual application? Maybe, for the part you decided to use, the technical writer was just a better writer.

I am interested to see what the opinions are out there. Let me know your thoughts regarding which components benefit from actual datasheets and for which components it really wouldn't matter.

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24 comments on “Datasheets: Technical Treatise or Marketing Manure?

  1. goafrit2
    December 20, 2013

    I think datasheets are both. There are companies that you cannot trust their datasheets because they have consistently exaggerated things. In that case, it becomes a marketing dossier with some professional lies. Yet, some companies put their reputations on their datasheets. For those ones, you can see them as Technical Treatise

  2. goafrit2
    December 20, 2013

    >> We think that reading through the data will save us time, but what if the components you did not select based on the datasheet were actually the parts that performed the best in actual application

    Your point is common when you shop from the company websites. Most times, those are low-grade parts  remaining from orders of big corporations. They will give them new names and sell them cheap to the masses. The highest quality ones are shipped to those that want defined statistical confidence performance intervals, otherwise, the lawyers are mobilized. People have wasted days at work with the mindset that the opamp they have in that test board is working. Some never know that it can be bad from the factory and sometimes, test to be sure it can be ON before you start troubleshooting you circuit

     

  3. fasmicro
    December 20, 2013

     I have actually met some engineers that do not ever request datasheets.

    If one knows the product and the PINS, there may not be need to be wasting time reading the datasheets. But notice that one of the reasons why startups suffer in the industry is what you have described. How do you expect a big firm to have trusts in these untested companies and their datasheets. The default is to work with legacy brands which have proven to be reliable over the years.

  4. Davidled
    December 20, 2013

    Well, company might use datasheet as the tool for their advertising purpose. Also, datasheet would be used for both engineer, designer and sales engineer including CEO. To reach this goal, it should be written logically based on all component data.  But I saw the typo and the lack of contents in technical documentation several times. In my view, the poor documentation provides neither technical treatise nor marketing manure.

  5. fasmicro
    December 20, 2013

    >> But I saw the typo and the lack of contents in technical documentation several times. 

    In most of these companies, marketing guys have the responsibility of developing datasheets and not the designers. From that, I see a pattern in the company's mindset – write it in a such a way that we can ship the parts. If they want the hard facts, may be, the designers and test team will lead the writeups. Typos in them, it means the firm is not serious and from datasheet you can know if a company is serious about its business.

  6. Jason Bowden
    December 21, 2013

    @dates…. Thank you for your opinion on the blog. Clearly your point and passion of datasheets is well taken. I should reiterate again in my blog that I have read at least 1000 datasheets and with my 14 years in the electronic industry think I have earned the right to discuss my view on this topic. Yes, I have met many engineers that do not spend a lot of their precious time reading as they feel they should be designing and testing. I probably would not work for a company that reacts in a non professional manner over small topics. Who knows what happens when something major comes along. I would not have to worry about being fired. I do appreciate the compassion you do have on the subject. Thank you for the reply.

  7. dates
    December 22, 2013

    Jason

    Your article threw me into something of a rage. I think the tone of my reply was too strong, so I will calm down.

    I take issue with your title that asks the question if datasheets are marketing manure.

    Engineers who don't STUDY the datasheet and read around their subject via technical articles are at high risk of repeating well-known mistakes that others have discovered before them. What you seem to be saying is that you know it all and reading such things is not worth your time.

    One of the traits of professionalism is that you continue learning by reading and attending training.

    If you only build and test then the risk is that on the board you test it will work fine, but not in production in volume.

    That is not to say that datasheets are perfect and all of them are 100% accurate. This would mean that they were written by perfect people.

  8. Jason Bowden
    December 22, 2013

    Thank you Actually, that was not the title I chose, but seems it was edited. My title was simply Datasheets: Technical or Marketing.

  9. Victor Lorenzo
    December 22, 2013

    @Jason: “I should reiterate again in my blog that I have read at least 1000 datasheets ” I could n't say exactly how many datasheets I've read, but I sincerely say I never read every single line from every page. I first do some skimming-scanning and go deeper and deeper as I'm getting close to the point I must make the choice. Some times I've needed to iterate. That method saves me time.

  10. samicksha
    December 23, 2013

    I guess there is very thin line difference between datasheet and factsheet, most of us use datasheets to get a general idea of what could work for us, rather than whats hidden behind the device.

  11. Victor Lorenzo
    December 23, 2013

    @samicksha, after reading your comment “I guess there is very thin line difference between datasheet and factsheet ” I went into the documents for the Kinetis K20@100MHz, from Freescale, as it was the one I remembered closer to what you say among the devices I'm currently using.

    They do separate the FactSheet (http://cache.freescale.com/files/microcontrollers/doc/fact_sheet/KNTSK20FMLYFS.pdf?fpsp=1) which contains a family overview. I found usefull the family options table. The datasheet (http://cache.freescale.com/files/32bit/doc/data_sheet/K20P81M100SF2V2.pdf?fpsp=1) contains more technical information but seems to be targeted at circuit designers. All the details required from the programmer point of view are given in a separate document, the reference manual and there they have several of them according to device package pins count and speed grades.

    At first it was a little bit neurons consumming as it was necessary to remember the document containing the information I was looking for (like the internal architecture of the ADC, timers, etc), but at the end I found it also practical.

    Do you have any example to share of what you comment?, I feel curious about it. Thanks.

  12. samicksha
    December 24, 2013

    @Victor, I understand what you say, what i mean to say here is both fact sheet and data sheet summarize an application's features and functions. The difference between these two types of documents – structure wise or content wise.

  13. Vishal Prajapati
    December 25, 2013

    In my experience, I have almost everytime got the useful information out of datasheets. I perticularly like the datasheets of Microchip. Generally it does contain almost every information that designer need. So, less likely to look around for other documents for required information.

     

    For most analog and discrete components the datasheets are merely a small feature description followed by parameter tables and few graphs. Most of them are useful for designers.

     

    Sometimes few marketing stuff is included inside the datasheet but along side useful information the extra bit is granted.

     

    So, in my opinion, the datasheets are more useful than mere marketing material.

  14. jkvasan
    December 25, 2013

    Jason,

    In my opinion, datasheets reflect the ideas of the enginner who writes them. Over years, datasheets have evolved with a uniform format and all the engineer must do is fill those blanks.

    There is a lot of information there all right… yet there are several readymade answers you always like to know. For example, the maximum frequency at which an optocopler works is hard to find. I know these devices have varied characteristics chip to chip. However, it would help to provide a typical frequency number.

    I only wish that the writers put themselves into our shoes and think out of the box.

     

  15. goafrit2
    December 27, 2013

     I probably would not work for a company that reacts in a non professional manner over small topics. 

    @Jason, certainly a blessing when one can make that decision. The job market makes it that people are stuck for years in places they do not like. And for the electrnics industry, unlike apps and software, taking the energy into a startup is not easy with a higher barrier of entry.

  16. goafrit2
    December 27, 2013

    That is not to say that datasheets are perfect and all of them are 100% accurate.

    Good point. The best way to learn a product in this industry is still the datasheet no matter your years of industry experience, you can learn as much from a product through its datasheet. That said, any company that cannot produce a decent believable datasheet does not deserve to be patronized. There are few things I think should not be controversial – one is datasheet. When you have the product and put it into action and the output does not conform to the datasheet, end the game!

  17. goafrit2
    December 27, 2013

    thin line difference between datasheet and factsheet

    Unfortunately, that is not supposed to be. Datasheet = factsheet for a product except that marketing guys driven to give customers any metric they want will cook it. The customers want 20 bits. They ask you to expend the last 10 bits to get extra useless 4 bits when those have not real technical value. The extension could make the product not real but when you look deeply (if you have experience), there is no deception. It has 20 bits for the ADC with INR/DNR of +/-2LSB which means it is simply not close to 20bits. Take them to court, you will lose because the publication is factful.

  18. SunitaT
    December 31, 2013

    The best way to learn a product in this industry is still the datasheet no matter your years of industry experience

    @goafrit2, I totally agree with you. I think the companies should take extra effort to make sure that the datasheets are reliable.

  19. SunitaT
    December 31, 2013

    I only wish that the writers put themselves into our shoes and think out of the box.

    @JAYARAMAN, I totally agree with you. I think companies should always take feedbacks from end users even after the datasheet is made public. They can always update the datasheets for any info which the end users are looking for.

  20. RedDerek
    January 2, 2014

    Thank you Actually, that was not the title I chose, but seems it was edited. My title was simply Datasheets: Technical or Marketing.

    @Jason – Brad does make some interesting titles. 😉

  21. RedDerek
    January 2, 2014

    For those that do not read the datasheet, the engineer should already be familiar with the product line in some way.

    I have found data sheets useful, even the old 4xxx CMOS ones, for I do not use the product often enough to know the pin out.

    As for other datasheets, I do find the information useful. Knowing the block diagrams within the device helps me determine whether a product can be used in my application or not. Furthermore, if careful understanding of the product can be ascertained, the product could be used in other ways that the manufacturer may not have envisioned – take the 555 as a power supply circuit. I have used a few other parts in an unorthodox method because I got a better understanding of the inners of the ic.

    I do agree that data sheets can be a form of marketing material – it should be. How else does a company convince an engineer to use the product.

    In my 23+ years of design and semiconductor jobs, I have read and written hundreds of datasheets. Overall, I do find them useful.

  22. goafrit2
    January 2, 2014

    >> I think the companies should take extra effort to make sure that the datasheets are reliable.

    Largely, we need to understand that products are made within a statistical deviation window which means some will perform better than others. We do not expect all to work exactly especially when you are buying these products from the company websites. Those are leftovers and most times degraded products made for some big clients. The not-great ones are renamed and sold to the outside world.

  23. goafrit2
    January 2, 2014

    @Sunita, it is not really a great idea to be updating datasheets with any infomation that users want. There are standards in most products and once a company has met them, they should be fine. It could be challenging to support mass market by answering all their questions when all they buy is sub $100 order. For big clients, they get a different type of datasheets because they are actually assigned a dedicated team from the OEM.

  24. goafrit2
    January 2, 2014

    >> For those that do not read the datasheet, the engineer should already be familiar with the product line in some way.

    I hope the person does not tell the HR or a hiring manager that he does not read datasheet. There is no way that can work out. It is simply not possible that an application engineer will not read datasheet and yet be in a position to do his job. How will the person understand the parts? It does not make sense to me. You put the product in a circuit and start doing what without taking time to read the datasheet that explains what to expect. 

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