Some semiconductor companies such as Broadcom and Microsemi do not publish the datasheets of some of their chips such as networking ones. It seems the companies do not provide the datasheets without an NDA. On the other hand, as far as I know the prerequisite for an NDA is an order for buying a high volume of chips (is it ture??)

So my questions are:

1- While some of the chips can be bought from electronic distributors, why do the companies not provide the datasheets?! What is the reason behind not publicly publishing the datasheets?

2- If I need a low volume of the chips, what should I do to access the datasheets?


closed as primarily opinion-based by Elliot Alderson, old_timer, Blup1980, Warren Hill, stefandz Jan 15 at 16:02

Many good questions generate some degree of opinion based on expert experience, but answers to this question will tend to be almost entirely based on opinions, rather than facts, references, or specific expertise. If this question can be reworded to fit the rules in the help center, please edit the question.

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    \$\begingroup\$ THe same reason why NDA's exist. \$\endgroup\$ – Sunnyskyguy EE75 Jan 13 at 8:23
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    \$\begingroup\$ They are scared of someone reverse engineering their product. My advice is to look elsewhere. I’ve had experience with Broadcom at one large company and their reluctance to disclose things even with NDAs (not everything is in the datasheet) resulted in us implementing our own comms stack. What type of functionality are you after? \$\endgroup\$ – user110971 Jan 13 at 8:36
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    \$\begingroup\$ @user110971 In my book, the datasheet of a chip does not provide considerable information for reverse engineering. I think there must be another important reason. I am looking for GPON controller and Ethernet switching chips. I cannot buy a lot of them so that I can sign an NDA. Even Chinese manufacturers do not provide the datasheets! \$\endgroup\$ – M.H Jan 13 at 8:50
  • \$\begingroup\$ @M.H I don't agree with that. having worked for a large company and having been responsible for the datasheets. \$\endgroup\$ – Oldfart Jan 13 at 8:57
  • \$\begingroup\$ Sometimes there is no good reason, just fear. Company x does this maybe we should. Management decides, dictates and it is game over. The cost to clone is as much as the cost to create so millions to tens of millions of dollars, to cut in on someones margins by pennies or dollars. In some cases the documents get leaked and the company doesnt care, in some cases the NDA holder simply publishes them. And I have not seen those cloned at all and at least one is one of the supposedly competitive companies. \$\endgroup\$ – old_timer Jan 13 at 15:29

The companies you mention are not the only ones who require an NDA for product information and with good reason. I have had to work under NDA with TI (processors), Freescale (QorIQ series prior to full launch and now part of NXP), Vitesse (multi-gigabit crosspoint switch in the late 90s), Intel (networking devices), Broadcom (networking devices) and others.

A complex IC such as a networking device requires a lot of software support. The register map and detailed data on how to operate the device is part of the data sheet / reference manual. The functionality of the device at the deepest level (including specific pin functionality) is also part of the documentation. There is a great deal more, but this is an example.

If it were publicly available, a competitor could duplicate that map, internal functionality and pin functionality and make a device that is a drop-in replacement, (they would need to design a device which could be worth it for a large market) but that would reduce the selling price of the original part; this would make the investment required quite possibly exceed any return on the investment from sales.

Given the amount of money (several million dollars) that is invested in the design of such parts, it makes sense for the manufacturers to protect their product in such a way to protect their business model.

A market where a device is selling millions would be a very tempting target. Think SnapDragon parts used extensively in many designs. In the case of Broadcom, their advanced switching parts have some very advanced features that make them very attractive in networking gear as one example.

There are many parts that are sourced from multiple vendors and they are typically inexpensive for the good reason that they are available from numerous sources.

Note that the parts with a large market share would be tempting targets; this is the reason that a lot of data sheets are publicly available; the market is not large enough for a competitor to design a drop-in replacement.

Such things are standalone high performance ADCs (the market is growing but they do not sell in quantities of hundreds of thousands or more) and other high performance devices.

The ultimate reason is that the semiconductor vendors business model relies upon protecting their IP; for the ultimate in that arena, try getting your hands on the internal details of an Nvidia GPU; I worked with one (in a mission computer) and had access to the hardware manuals, but the software interfacing had to be done via a third party that works directly with them.

Each vendor has its own take on NDAs. Some may require a commitment to a minimum number of parts, others may not. I used Broadcom ethernet parts when I was at a startup that had the potential to use a lot of parts, although it ended up that we really did not use a huge amount.

The NDAs I have had varied widely; I even had a situation where a product line was bought up by a different company and parts that I had been able to get data for with no restrictions suddenly had to have an NDA; the opposite is also true - PLX required an NDA for a lot of their PCI express parts, but when they were bought by Avago (now part of Broadcom), the NDA requirement disappeared.

As noted in the comments, a lot of companies do not respond to emails from some domains (particularly educational, but in the past gmail, aol and the like were ignored).

  • \$\begingroup\$ Thanks @peter-smith. What are prerequisites of an NDA? Do I need to buy a lot of a chip to sign an NDA? or I can sign an NDA and get datasheets without buying a lot of them? \$\endgroup\$ – M.H Jan 13 at 11:28
  • \$\begingroup\$ @M.H why not ask the company - they write and decide their NDA... They will tell you soon enough yes or no... \$\endgroup\$ – Solar Mike Jan 13 at 11:41
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    \$\begingroup\$ @SolarMike Actually they do not answer emails from a university domain! I am a student. I wanted to know your experience and then plan for future. \$\endgroup\$ – M.H Jan 13 at 11:55
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    \$\begingroup\$ @M.H depends on who and how you approach - many companies work with universities for research and development - even funding expensive equipment in the uni to get research done for them by faculty and top-flight students whose time, effort and skills they could not get otherwise. \$\endgroup\$ – Solar Mike Jan 13 at 12:43
  • \$\begingroup\$ @M.H Ask any professor(s) involved with your project, like your instructor or thesis supervisor, if they know anybody at the company. An inside contact can be a big help figuring out hoops to jump through to get an NDA. \$\endgroup\$ – The Photon Jan 13 at 15:33

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