Path: ...!Xl.tags.giganews.com!local-1.nntp.ord.giganews.com!nntp.supernews.com!news.supernews.com.POSTED!not-for-mail
NNTP-Posting-Date: Thu, 02 May 2024 23:38:01 +0000
From: john larkin <jl@650pot.com>
Newsgroups: sci.electronics.design
Subject: Re: Declining datasheet quality
Date: Thu, 02 May 2024 16:38:01 -0700
Message-ID: <ct883jhedn8c69nc22eh8stqvcvca7laj3@4ax.com>
References: <v0s3q3$2pcac$1@dont-email.me> <6j533j1rloi61f1ean3c49ar8rbp8u69up@4ax.com> <ado73j17bssfmifmdlcdpnm0kmljp3k4di@4ax.com> <v113fg$3lau$1@dont-email.me>
User-Agent: ForteAgent/8.00.32.1272
MIME-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 8bit
Lines: 69
X-Trace: sv3-cn2B1ZnAx3zned4JmMaPqi9j2YhQmN694WCDfKvbDS8of1Ibqdn15cNbuZJYEE1xGicJJa3wwB/rOUc!D168AyCmgy6DFT5SJCJIkPXAVFuK3afPBi8vKrPCbAWDQ3z/+l4/MfOyljCeyUpoW4kIqpPDnMcZ!TWk6Lg==
X-Complaints-To: www.supernews.com/docs/abuse.html
X-DMCA-Complaints-To: www.supernews.com/docs/dmca.html
X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers
X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly
X-Postfilter: 1.3.40
Bytes: 3857

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.