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Rant: Top View vs Bottom View on Datasheets.
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tggzzz:

--- Quote from: SiliconWizard on April 14, 2023, 07:58:06 pm ---What is top and bottom anyway? Do the australians not live upside down? :-DD

--- End quote ---

They don't think so. But then they do think that during the course of the day the sun goes from right to left.
TimFox:
Bottom view, with pins labeled in a clockwise direction, was the standard for vacuum-tube base diagrams, since tube sockets were always wired from the bottom.
Old conventions can live on.
vk6zgo:

--- Quote from: TimFox on April 14, 2023, 10:45:40 pm ---Bottom view, with pins labeled in a clockwise direction, was the standard for vacuum-tube base diagrams, since tube sockets were always wired from the bottom.
Old conventions can live on.

--- End quote ---

Exactly, & it made perfect sense, as analog clocks all were numbered that way.
If you were probing tube sockets from the top, you just (easily) kept in mind that the rotation was a mirror image of the normal diagram.
With the first DIL ICs, as people trying to troubleshoot them were as likely to be probing the pins from the top or bottom of the PCB, it again made sense to maintain the clockwise diagram, as those brought up on tubes would automatically make the adjustment.
It was found, though, that much probing was done from the top, so it became more common to show the top view, with the numbers naturally rotating anticlockwise.

Discrete transistors were normally probed from the bottom, so it became natural to draw them, or anything else in a similar package from the bottom view.

If you want something confusing---back in the day, optocouplers were commonly packaged in a 6-pin package (DIP 8 with two missing pins).
As they were seemingly all pin for pin compatible, & many had very similar characteristics, it became relatively common to swap types with little chance of a problem.
Siemens, however, decided to go their own way with a totally different pinout to optos which were otherwise similar to "jellybean" ones.
A "trap for young (& old) players!
vk6zgo:

--- Quote from: tggzzz on April 14, 2023, 10:15:36 pm ---
--- Quote from: SiliconWizard on April 14, 2023, 07:58:06 pm ---What is top and bottom anyway? Do the australians not live upside down? :-DD

--- End quote ---

They don't think so. But then they do think that during the course of the day the sun goes from right to left.

--- End quote ---

It does that if you look towards the North, no matter where you are.
tggzzz:

--- Quote from: vk6zgo on April 15, 2023, 01:56:18 am ---
--- Quote from: tggzzz on April 14, 2023, 10:15:36 pm ---
--- Quote from: SiliconWizard on April 14, 2023, 07:58:06 pm ---What is top and bottom anyway? Do the australians not live upside down? :-DD

--- End quote ---

They don't think so. But then they do think that during the course of the day the sun goes from right to left.

--- End quote ---

It does that if you look towards the North, no matter where you are.

--- End quote ---

Not if you are standing on your head.

If you can't see the sun moving, it doesn't count :)
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