• Declining datasheet quality

    From Don Y@21:1/5 to All on Tue Apr 30 17:53:18 2024
    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"?)

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From John Larkin@21:1/5 to blockedofcourse@foo.invalid on Tue Apr 30 18:20:53 2024
    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

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From john larkin@21:1/5 to jjSNIPlarkin@highNONOlandtechnology on Thu May 2 11:59:38 2024
    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.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Phil Hobbs@21:1/5 to john larkin on Thu May 2 22:18:24 2024
    john larkin <jl@650pot.com> wrote:
    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.



    Good idea.

    I’d be very surprised if it were monolithic—you’d need extra die thickness
    for the isolation, and there’s no benefit versus just using two dice. Plus of course it would be a lower volume special purpose part.

    Cheers

    Phil Hobbs

    --
    Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From john larkin@21:1/5 to john larkin on Thu May 2 15:56:02 2024
    On Thu, 02 May 2024 11:59:38 -0700, john larkin <jl@650pot.com> wrote:

    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.

    https://www.dropbox.com/scl/fi/eahb9v65w2d13isrbsw5a/208-1006.jpg?rlkey=ist02aewzmdz9rjly97ie4ry4&raw=1

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From john larkin@21:1/5 to pcdhSpamMeSenseless@electrooptical. on Thu May 2 16:38:01 2024
    On Thu, 2 May 2024 22:18:24 -0000 (UTC), Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:

    john larkin <jl@650pot.com> wrote:
    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.



    Good idea.

    I’d be very surprised if it were monolithic—you’d need extra die thickness >for the isolation, and there’s no benefit versus just using two dice. Plus >of course it would be a lower volume special purpose part.

    Cheers

    Phil Hobbs

    Dual transistors usually aren't.

    --- SoupGate-Win32 v1.05
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