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 Newsgroups: sci.electronics.design Subject: Re: Declining datasheet quality Date: Thu, 02 May 2024 16:38:01 -0700 Message-ID: References: <6j533j1rloi61f1ean3c49ar8rbp8u69up@4ax.com> 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 wrote: >john larkin wrote: >> On Tue, 30 Apr 2024 18:20:53 -0700, John Larkin >> wrote: >> >>> On Tue, 30 Apr 2024 17:53:18 -0700, Don Y >>> 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.