For example: the LM317. Wikipedia says it was invented by National Semiconductor employees in 1970 — but now if I search for "LM317 datasheet" the results include PDFs from Fairchild Semiconductor, Texas Instruments, ON Semiconductor, Thomson Microelectronics, STMicroelectronics. Perhaps there is some variability, advantages one might have over another, but my understanding is that any LM317 is theoretically fungible for another.

I'm wondering how this comes to be, and if there's any term for this — something like "reference component" or "standardized IC"?. Now in the case when an intellectual property is violated, you might have "knockoffs" of a "proprietary" chip design. And certainly you could have legitimate licensees, like ARM does with their design cores.

But many components, say a 2N3904 transistor or IRF530 MOSFET or the aforementioned LM317, seem to be something of public domain designs yet meeting some sort of industry standard specifications.

Who sets the standards for these sort of standard components? Is there any central authority for their identification? Or is it as simple as that an original inventor both created and named a particular chip of their own as usual, but if it became popular enough, other manufacturers just began to manufacture (legal) "knockoffs" under the same name/parameters as soon as any monopoly rights expired?

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    \$\begingroup\$ Back in the day, the US government (military) drove a lot of the standard practice in the electronics industry. And they insisted on having multiple sources for each component. So they would demand, for example, that National would license their design to at least one other company before they'd agree to buy the part. And so National would do that. \$\endgroup\$
    – The Photon
    Feb 27, 2015 at 23:38
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    \$\begingroup\$ What you don't see in the datasheets is the actual design and manufacturing cost. A second source needs to either perform better, or have lower cost (thus potentially lower selling price, or higher profit margin) to be a viable product. Mostly these are ad hoc standards, based on the original product datasheet x second source mfgr test limits. \$\endgroup\$
    – MarkU
    Feb 28, 2015 at 0:29
  • \$\begingroup\$ Related: electronics.stackexchange.com/questions/142220/… \$\endgroup\$ Feb 28, 2015 at 1:41
  • \$\begingroup\$ Thanks for interesting the comments so far! And via that related question I came across some useful related terms "logic family" and "pin compatibility" that may be related to an eventual answer here. \$\endgroup\$
    – natevw
    Mar 2, 2015 at 23:26

1 Answer 1


The inventor is the one who names the component, and the company can sell or license the rights at their discretion, popular components usually end up being licensed because the demand is so high. The original manufacturer still gets a percentage of the profits made by selling the product. The companies usually are required to keep some of the basic characteristics the same, by the original inventor, but some differences are allowed and that is why each company provides their own data sheet, because some designs may need special consideration. Logic families are basically the same, they are a series of popular components that get licensed and/or copied. Pin Compatibility is a buzzword, and is how manufacturers advertise the fact that their component is a drop-in replacement. This is based on what my engineering friends have said, and based on the comments provided here. Also logic families are usually based on the transistor technology and the voltages used to represent a binary 1 and 0; for example, Transistor-Transistor Logic (TTL) gates use about 5 volts for a "1" and about 0 volts for a "0" while Complementary Metal Oxide Semiconductor (CMOS) chips usually use 3.3 Volts for a "1" and 0 Volts for a "0". Modern CPU's may even use as low as 1.2 Volts for a "1". Parts from the same logic family are electrically compatible with each other. Looking up "logic family voltages" may also provide you with additional information.


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