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From: john larkin <jl@650pot.com>
Newsgroups: sci.electronics.design
Subject: Re: Declining datasheet quality
Date: Thu, 02 May 2024 11:59:38 -0700
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On Tue, 30 Apr 2024 18:20:53 -0700, John Larkin
<jjSNIPlarkin@highNONOlandtechnology.com> wrote:

>On Tue, 30 Apr 2024 17:53:18 -0700, Don Y
><blockedofcourse@foo.invalid> wrote:
>
>>A colleague teaching a STEM course asked me for some details on WS2812's.
>>Digging through the datasheets I've been able to find seems like they
>>are sold only to hobbyists -- or, at least not to folks who have to
>>*design* with them!
>>
>>I can't seem to find any specification of Icc -- at MAX (255.255.255)
>>intensity and "dark" (0.0.0).
>>
>>Nor anything giving thermal characteristics of the package beyond
>>ambient (70C) and max junction temperature (80C) -- I suspect it
>>wouldn't be hard to melt the things if they dissipate any
>>appreciable amount of power!
>>
>>Is this the "typ" trend taken to its logical extreme (where we
>>don't really care how it MIGHT work in a given environment, beyond
>>"try it and see"?)
>
>Data sheets are increasingly awful. Some don't even say what the part
>does. Some mechanical drawings have missing dims. And where is pin 1?
>
>People randomly distribute abs max, pin function tables, equivalent
>schematics, electrical characteristics, whatever. Often there is no
>date or version number. File names are bizarre, unrelated to the part
>number.
>
>I especially hate a data sheet that covers a bunch of parts and
>doesn't tell you what the difference is between them.
>
>Or covers a zillion parts and makes me build the part number, and then
>guess whether it's an available thing.
>
>This isn't really bad:
>
>https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://cdn-shop.adafruit.com/datasheets/WS2812.pdf&ved=2ahUKEwi9sYqdpOuFAxV6IDQIHX-dCJ0QFnoECB0QAQ&usg=AOvVaw2wZFi_i6GR7eWbT12yqVZd

Here's a good (ie, bad) data sheet example.

https://www.rohm.com/datasheet?p=SH8JC5&dist=Digi-key&media=referral&source=digi-key.com&campaign=Digi-key

It's not clear when they are talking about one die or two. The word
"and" is not helpful.

It's not clear if this is one or two die, which can matter. I'll x-ray
one.