The official JEDEC standard to number pins on a TO-92 package is the following: enter image description here

But in many datasheets from Texas Instruments, this order seem reversed. For example, this is a screenshot from the datasheet for the LM185 :

TO-92 from LM185

Link to the full datasheet : http://www.ti.com/lit/ds/symlink/lm185-1.2-n.pdf (page 1)

Texas Instruments's official TO-92 documentation doesn't help since there is an ambiguity as if the drawing is from the top or the bottom : http://www.ti.com/lit/ml/msot002d/msot002d.pdf

In all the datasheets where the pinout is reversed, they used a view from the top or the bottom. In some datasheets the pinout is correct, but they used an isometric view which eliminate all ambiguity. This could be the source of the confusion, but I just don't see how I could misinterpret "Bottom view" or "Top view" for a TO-92 package.

Is Texas Instruments wrong or I don't understand what a bottom view is?

To prove that this is not an isolated mistake in a single datasheet, here are few links to some Texas Instruments datasheets where this happen :

http://www.ti.com/lit/ds/symlink/tl431.pdf (page 4)

http://www.ti.com/lit/ds/symlink/lm285-2.5.pdf (page 3)

http://www.ti.com/lit/ds/symlink/lm4040-n.pdf (page 4)

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    \$\begingroup\$ Please don't assume that Wikipedia or "the internet" is an official source for any information like this. If you want to know what is correct you must find the actual standard, as @TimWescott did. \$\endgroup\$ Aug 10, 2019 at 23:40

3 Answers 3


The LM385 was originally produced by National Semiconductor. The earliest reference I can find is from their 1980 Linear Databook. It shows the same 'wrong' pinout. Other manufacturers whose datasheets have the same pinout include Motorola and Telcom Semiconductor.

So it seems the 'wrong' pinout originated at National Semiconductor, and has been copied by second-source manufacturers. Texas Instruments acquired National Semiconductor on September 23, 2011. This would have given them the opportunity to use National's datasheets for parts they were second-sourcing.

LM385-1.2 NS Linear Databook 1980

NS Z03D package drawing


I don't see any ambiguity in any of the datasheets, and the only one that disagrees with the conventionally accepted numbering scheme is the first one. The others show the pins in solid lines (not dashed) so they are clearly bottom views.

By the way, TI was not the originator of the LM385 chips, rather they bought National Semiconductor. You can find the same numbering scheme on NS datasheets, for example here. The part is rather old, the same pin numbering is shown on page 2-47 of NS's 1982 databook (the oldest one I happen to have on hand), it probably dates back to some time in the 1970s. The databook refers to NS Package number Z03D, and you can find a datasheet for that package here

enter image description here

As you can see, it's consistent with your LM385 datasheet, but inconsistent with more modern numbering.

A relevant question might be when (or even if) numbering for the TO-92 package was standardized. I don't recall it being standardized during those years, instead we would use E-B-C or similar letters for the pin designations.

For what it's worth, alternate sources of the LM385 et al may disagree on what number to use for a given pin, but they certainly agree on the pinout, however you number them. The part is somewhere in the range of mature to obsolescent in life cycle so it's not much to worry about provided you follow one data sheet and don't mix datasheets.


You could hunt down the JEDEC TO-92 standard yourself. I've included the link, but you need to register (for free).

Yes, TI disagrees with JEDEC. But as long as your board works, does it matter?

  • \$\begingroup\$ How can Texas Instruments, one of the world biggest semiconductor manufacturer, disagree with JEDEC? Also, it's the point of this question, my board have a 50% chance of working since i don't know if I should refer myself to the figure or the table of the datasheet. \$\endgroup\$
    – Iouraxos
    Aug 10, 2019 at 23:42
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    \$\begingroup\$ @louraxos, TI may have been using their numbering since before JEDEC standardized theirs. \$\endgroup\$
    – The Photon
    Aug 11, 2019 at 0:26
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    \$\begingroup\$ ti.com/lit/ds/symlink/lm185-1.2-n.pdf (SVNS72E - revised April 2013) page 1 figure 1 LP package pin numbering does indeed appear to be inconsistent with the package drawing LP0003A on page 22. The package drawing note 4 explicitly makes reference to JEDEC TO-226 variation AA, which uses a bottom view consistent with the drawing. You should contact ti.com applications engineering support, it's possible that this is an error in their datasheet. At the very least, it's confusing and not self-consistent within the document, so you have every right to demand TI address your question. \$\endgroup\$
    – MarkU
    Aug 11, 2019 at 0:28
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    \$\begingroup\$ @louraxes, TI has acquired several other companies over the years. Some of those parts might be inherited from other companies that used the JEDEC numbering. Or some TI divisions might have chosen to adopt the JEDEC numbering while others didn't. \$\endgroup\$
    – The Photon
    Aug 11, 2019 at 1:08
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    \$\begingroup\$ @MarkU I'm waiting for TI response, I'll post it when I have it. \$\endgroup\$
    – Iouraxos
    Aug 11, 2019 at 1:10

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