Unsung Beauty of Analog Devices Datasheets | Hacker News Reader

Unsung Beauty of Analog Devices Datasheets

neil.computer

173 pointsneilpanchal65 comments

Former Analog Devices employee here. I used to write programs and that collected all of the data for the data sheets. We would take all of these complex measurements on a part in just seconds using some pretty fancy test equipment. It definitely taught me a lot / inspired me to learn more about programming as a a fresh-out-of-school EE

Definitely happy to see some data sheet love ..chip companies are definitely in a whole different world when it comes to documentation, compared to the software world I'm now in!

Analog Devices' datasheets and application notes taught me so much I didn't learn formally, especially in regards to circuit design in real-world conditions. On the average, they're a real pleasure to read and, generally, you can tell people who actually used the parts to build things had direct input into the datasheet design and layout. As you contributed to that, thank you for making this hobbyist's life better and less stressful. I can only hope Analog Devices permits their staff to publish more about their process for designing, building, and maintaining documentation as they do.

I'll double check if there was anything interesting about how we did documentation lying around. One thing I did want to point out if you like the application notes, is you definitely owe it to yourself to check out the companies tech journal Analog Dialogue

Yes they will try to point out interesting parts they make, but it's like the next level beyond the application notes and a great way to see some practical designs and applications of analog circuit theory in the real world.

https://www.analog.com/en/analog-dialogue

The "rarely asked questions" archive usually has some fun ideas in it, like a white noise generator based on johnson noise from a resistor (https://www.analog.com/en/analog-dialogue/raqs/raq-issue-154...), or a signal chain for doing analog measurements on a single GPIO pin on an FPGA, complete with verilog code (https://www.analog.com/en/analog-dialogue/raqs/raq-issue-169...)

Awesome! :)

That's awesome! I learned a ton about buck regulators from the ADP3050 datasheet [1]. The rest I know about switching regulators, I learned from the LT3757A [2] (now the same company of course). I built a 20V to 190V boost regulator at the very edge of capabilities of the LT3757A for a nixie tube clock project -- that learned me an awful lot haha, in particular that next time I'll be using a flyback topology.

[1] https://www.analog.com/media/en/technical-documentation/data...

[2] https://www.analog.com/media/en/technical-documentation/data...

Fellow boost supply designer here. The problem I always had with flyback is that you can't get an off-the-shelf transformer. How would you solve that? Wind your own?

I really like coilcraft, which isn't stocked at DigiKey so you might never hear of them if you look there first. They have a lot of winding options and I think even their custom winding parts are reasonably priced.

I was under the impression you could use off-the-shelf transformers, at least some of the time [1] but I don't know what I'm doing ^_^

[1] https://www.coilcraft.com/edu/flyback_transformer.cfm

"..chip companies are definitely in a whole different world when it comes to documentation, compared to the software world I'm now in!"

Makes sense though. SW is a much more agile/faster iterations artifact than HW. Documentation is very hard to keep pace in this env, so much so that people are actually trying to infer it automatically from the -ever changing- code.

Your wording shows the difference very well: ~"Documentation that we have to keep updating" vs. "datasheet" (a specification).

Data sheet culture at these old-line semiconductor companies - ADI, TI, Linear - descends from the fact that you used to hold it in your hand and read it on paper. When I was in that field we went to the company library to read datasheets because ISO9001 required the company librarians to record which revision of which part an engineer read at what date and time. And it was partly sales literature because you'd be flipping through a bound volume of ADI's current parts looking for something suitable.

If you really want to get the whole experience then I urge you to print these out. The graphics are high-resolution.

Those were also the days when a radio or TV set came with full schematic diagram in the manual, and IC data sheets also contained the full internal schematics of a part rather than just a block diagram or a simplified schematic without parts values.

Sounds like you’re just a little older than me :-)

Possibly yes, I was just a kid in the mid 70s and have memories of those enormous books filled with TV schematics the repairman had at his shop, also every TV was accompanied by its own one. TV manufacturers kept distributing schematics until mid to late 80s, then stopped. Unfortunately back then scanners and the needed storage were almost science fiction, and the format would have hard to scan anyway due to the huge page sizes, so most of those books are either lost or sold at absurd prices online as vintage.

A couple recent exceptional datasheets I've come across include ADI's ADA4530 [1] and Renesas/Intersil's ISL28110 [2]; both, coincidentally, happen to be for regular old op-amps. The ADA4350 datasheet in particular is absolutely stunning and proof that the old ways are not completely gone. The ISL28110 datasheet is notable when, in an era when I all too often need to read between the lines to determine the type of input transistor used (seriously, guys, it's not hard to show and there are only six possibilities so it's not like you're giving away secrets here), they show a complete device model.

That said, I still miss LTC, NSC, and the pre-Renesas Intersil.

[1]: https://www.analog.com/media/en/technical-documentation/data...

[2]: https://www.renesas.com/us/en/www/doc/datasheet/isl28110-210...

Thanks for sharing, old ways are definitely not gone but eroding away sadly.

One of things I find amazing about the datasheet culture is that there is minimal marketing bullshit (although there are exceptions, I am looking at you, ST Electronics). Skimming through ADA4350 datasheet, I see no trace of any kind of trickery that we usually see in other industries. Datasheets are the thing people look for and since the audience is engineers, they won't put up with marketing nonsense. As a consequence, there is almost perfect objectivity in selling a product - based on features, performance, operability, etc. Since decision makers are engineers, data and specifications prevail.

(Full disclosure, former AD employee)

In particular with precision Analog / mixed-signal / RF, there is a real recognition that there is no perfect Amplifier / Converter / Black Box X, that will satisfy all applications. That all abstractions (and inputs) are leaky, a wire is never just a wire, ground is never ground, noise exists, etc. That the reality is that there are myriad tradeoffs to be made depending on what you want to do, and the best way to be successful is to acknowledge that fact from the start without any bullshit; And as a supplier to tell you exactly what those real-world tradeoffs are and help guide you towards being successful.

To their credit the applications engineers and even sales folks when I was there were just as happy to sell you a $.05 "jellybean", as they were to sell the latest precision laser-trimmed FancyAmp if that's all you needed because they were like minded engineers too, and at the end of the day, building something that did the job it needed to was satisfying.

(Plus, as anyone whose done consumer/ high-volume electronics will tell you, BOM cost is it's own variable in the optimization space that can lead to some creative design choices!)

Kind of a rant, so forgive me for venting out :)

An untold truth is that datasheets are also the terrain for disputes with tech support. That is, there is a whole team of people called Application Engineers in said companies dedicated to support, that basically knows very little about the practical side of the product and all they do is to read datasheets, just in case there are engineers out there that design products without studying it.

So in order to pass the first (and usually not very helpful) line of support you better study the datasheet because it will be a sort of "legal" document you will have opened in your screen for the next week, until the application engineer gives up and connects you with someone who knows the product.

Regarding the quality of documentation, yes, nobody beats old monsters like AD. In regards of reference designs... AD is used to give you a 10"x10" board to evaluate a tiny little component; let's say a battery charger. Of course the reference design board has traces of the width of a thumb, very big gold-plated connectors for the power supply, etc. So when you go and integrate the little component in your wrist watch and it doesn't work, the application engineer will go with: "yeah, your design is not much like the reference design, so it's kind you will run into trouble.".... Imagine the rage...

Many years ago I was on a team designing a "smart sensor" box. The heart of it was an integrated precision A/D + 8051-compatible microcontroller chip from Analog Devices:

https://www.analog.com/media/en/technical-documentation/data...

None of us has ever worked with microcontrollers before. It was my first ever job out of school. I don't think we would be able to deliver the product if the chip datasheet was not awesome. It had everything. Memory organization, registers, peripherals, board layout and grounding recommendations, ADC driving, etc.

Thank you, Analog Devices engineers.

When teaching students about datasheets, I generally pull up an AD datasheet and state, "This is what a good datasheet should look like."

They're not the only makers of good datasheets, but they're very consistent. (and many of their chips are awesome)

Yeah, as someone who's self taught AD and Linear data sheets were always awesome and a great source of information.

Linear Technology's AN47 "High Speed Amplifier Techniques" is my favourite document in this category. It is both nicely presented, and a great resource for high performance electronics:

http://www.linear.com/docs/4138

Linear AN65 is another classic, even if you don't need any of the topologies.

And LTspice is extremely powerful for a free tool, if challenging to learn.

I wish the Mac version wasn't such garbage. It's missing most of the hotkey support that makes the Windows version such a breeze to use.

I use the Windows version, I wouldn't want to use it without hotkeys

All of Jim Williams' app notes are absolutely top notch.

Williams definitely wrote his stuff for a different generation of engineer - a generation where not everyone had access to the internet, and it behooved LTC to pack as much info into one document as possible.

The mark of just how good AN-47 is that, even in the age of the internet, it's still one of the best go-to guides on high speed opamp design and the attendant/surrounding challenges. Particularly concerning proper oscilloscope techniques for accurate measurements of high speed circuits.

Thank you, this one is my new favorite too! Such beautiful photos of ugly construction.

https://www.google.com/search?q=ugly+construction

And this: "The bit pushers have commented software; why not commented hardware?"

All a matter of perspective, I suppose. Certainly not as clean as a PCB, but a PCB is not as obviously cared about as this type of circuit. Manhattan swags have an air of being fretted over and tweaked that I find very appealing.

I can't help but be impressed at those manhattan style layouts.

To clarify, I did not mean "ugly construction" as a criticism. It's just what we called this style (with great respect) back in the day.

I have "datasheet-envy".

I'm one of the co-founders at satsearch [1], where we're working on fixing procurement in the space industry. We're constantly battling shitty datasheets.

As a space engineer, I found it infinitely frustrating to work with flyers that suppliers provide on their website, that also double-up as preliminary datasheets. They're messy, inconsistent, and subject to whatever the supplier thinks their buyer might want to know.

We wrote a blog article about the mess that exists in the space industry [2], and a follow-up about what we think can be done to improve this through Electronic Data Sheets (EDS) [3].

The EEE industry seems streets ahead in this regard, which is perhaps primarily down to strong commercialization and rapid growth of the market over the past 20 years. I think with companies like Octopart [4] making it patently obvious who does a good job of supporting engineers, it might also have pushed suppliers to improve their documentation.

I'm curious though about the consistent use of PDFs. I understand from a usability point of view that they're great for documents, but I would have imagined that the EEE industry would have started distributing "smart documents".

To give you an example, the AD datasheet in this article includes a number of high-res graphs: why has the sector not moved to the point where these graphs are interactive elements that you can zoom into, programmatically read off of, export data from, etc.? The way I look at it, a Juypter notebook or something similar would be an awesome way to share datasheet content, allowing much more interactivity.

Anyone with any thoughts as to why datasheets haven't progressed in that direction?

[1] https://satsearch.co

[2] https://blog.satsearch.co/2018-02-21-building-better-datashe...

[3] https://blog.satsearch.co/2018-01-23-the-challenges-of-an-en...

[4] https://www.octopart.com

On the other hand, TI's datasheet quality seems to have gone downhill, ST and Infineon's has always been horrible, and Broadcom is infamous for not releasing them at all.

Back in the day the saying was "lies, damn lies, and datasheets." The relatively rare companies that put out good datasheets were my heroes.

Most electronic engineering component-related documentation is good. It has a long history tracing back through National Instruments.

Intel's 80386 documentation was superb.

I believe you mean National Semiconductor

NI is an instrumentation board maker that got started in the 80's.

One other interesting repository of design knowledge: Texas Instruments' reference design catalog.

TI will give you the plans to build all sorts of machines and gizmos using their chips. ATMs, industrial robots, blood oxygen meters, even oscilloscopes - you can find detailed design information (schematics, BOMs, layouts, etc) on TI's website, free of charge.

A huge amount of manufacturers offer designs here's a curated compilation.... https://www.digikey.com/reference-designs/en

True. I just like TI's as an example because they cover so many use cases and market verticals.

I owe a great deal to National Semiconductor and their application notes. Prior to college I tought myself a lot of what I know about analog design from this handbook [0]. I remember in middle school calling up the support line and having an extremely patient applications engineer walk me through my design and point me at resources to learn. He always answered my emails, even though I'm sure he had more important questions to answer. I tried several years ago to track down the emails to contact him again and thank him, but those emails seem long gone.

http://mirror.thelifeofkenneth.com/lib/electronics_archive/N...

IMO - This article is an over simplification. Data sheets need to be book worthy documentation due to the behavior of complex semiconductors. I believe Datasheets are law abiding documentation? If something is out of spec or out of characteristics is is considered faulty which means loss of money or competitors can get in.

What I'm really interested is in what peoples opinions are regarding the navigation of content and material of these large scale Semiconductor Sites. They have 50k plus products which are all very complicated and specific to a use-case. I find there is a constant struggle to route people to the right solution especially when engineers can use different parts in new creative ways. ADI, Texas Instruments, and Maxim all fall in this boat.

> Datasheets are law abiding documentation?

Ideally true, but in practice I’ve seen certain performance claims (such as battery cell capacity degradation in a battery data sheet) aren’t accurate or depend a lot on your application. If they are reputable, I assume they are trying to estimate an honest average.

Navigating the sites are challenging when I don’t already know which part I want, for sure. I wish there were better ways to explore sites for certain keywords in a data sheet.

Do search engines like Octopart or Digikey help?

Digikey has one of the better search engines, not least because you get preview thumbnails of almost everything, and you can search in single unit quantities. It also has some intelligence when filtering parts by value (eg Leds by wavelength).

The problem is usually knowing the names of things, and eventually you learn what keywords to search for eg 2row 10way for a 2x5 connector. Everything is mostly standardised.

Octopart is best for finding stock, I wouldn't use it to locate a new part.

For finding new chips, like random sensors, the best way is to trawl the major IC websites (Ti, Max, etc) and see what pops up. You can still get samples from most of these places, and of quite expensive parts too.

>I believe Datasheets are law abiding documentation? If something is out of spec or out of characteristics is is considered faulty which means loss of money or competitors can get in.

There are plenty of errors in datasheets. Analog Devices even has this disclaimer at the bottom of their datasheets:

"Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice."

TI's website is still pretty decent for navigating around and finding the parts that'll solve your problem. ST seems to be making it harder and harder. The former Linear website was very easy to use. Maxim has always sucked, in my experience. NXP has an OK website but generally quite good datasheets.

If you're designing electronics for profit (not hobby), reach out to your local non-stocking distributor (Arrow, Avnet, Future, etc) and ask to talk to the local sales person and FAE. Tell these people your problem. They have contacts at a bunch of semi vendors and the FAE's main job is to know what parts do what. A good local FAE and sales person are worth their cost when you're trying to find what parts to use, even though they get much less useful once you're into the minutia of any given part or design.

Finding good and cheap ways to solve electronics design problems really comes down to experience. Not that you've done a ton of designs yourself but more that you've looked at a variety of ways that other people have solved problems and then tried to understand why they did it that way. Working at more than just one company where you get to do design reviews is a huge help with this. Ask lots of questions at design reviews, challenge the designer on why they're doing things a particular way even if you don't know how to do it better, the designer probably contemplated a handful of ways to solve the problem and will be happy to explain their decision to you. It's also helpful if you can work with a team who are trying to build low volume (<10k units per year) products and a team building high volume (>1M units per year) as there's very different tradeoffs that engineering, manufacturing, and the business are willing to make as volumes change.

ADI has gone down hill. For example, the HMC6300 datasheet is crap, having wrong register values, and lacking the interfacing details. Hittite, prior to ADI, would have never had a poor data sheet like that. The ADI web site also stinks, compared to what was Linear Technology.

I believe the Signetics 25000 series 9C46XN document is arguably the pinnacle of datasheets:

http://www.repeater-builder.com/molotora/gontor/25120-bw.pdf

Oh good, someone posted this! By far the best datasheet ever written.

The data sheets of AD, National, TI et al have also followed a pretty standard format in terms of layout, order of descriptions etc (something that I have always assumed predated semiconductors). This helps make them particularly useful.

Reminds me of the cartoons in Tektronix manuals:

http://w140.com/tekwiki/wiki/Tektronix_Cartoons

I think it was recently discussed on HN.

To really understand what the author is getting at it helps to have some experience with lower quality data sheets from other manufacturers. Take, for example, the WS2801, a popular LED driver chip from World Semi[1]. All of the necessary information is there (I used it to successfully wire them up and bit bang the LED colors) but it's just not pretty. The blue header is jarring and the graphs are screenshots from a scope.

[1] https://cdn-shop.adafruit.com/datasheets/WS2801.pdf

They do make beautiful documentation, so clear concise and well ordered. Would be nice to see who the authors are but I suspect they might be introverts. Certainly show a love for their work

"hehehe, I remember my first krabbie patty".

Looks like someone stumbled across a data sheet, and never read any before. Almost all of them look like that. Ti, NatSemi, ON, DIODES-inc, NEC, Toshiba, etc, etc. Ti and National Semiconductor used to be great reading for new engineers.

I really love sites full of gorgeous, detailed images that block my browser's zoom feature. /s

Can't you just download the pdf?

Probably. I'm on transit, browsing the news on my phone after a long day, and the site exceeded my current tolerance for inaccessibility. Sometimes site owners see these comments, or I wouldn't bother griping

"Open in browser", maybe?

I apologize and thank you. Didn't realize that the <meta> tag prevented the viewport from scaling. I've fixed it:

    <meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=yes" />

Perfect! Thanks!

There is no JS or anything on the page (besides what Ghost blog puts out for metadata). I am getting 99/100 on Google page speed test as well.

I tried zooming in on images using iPhone X / Safari and there is no issue. Are you sure something isn't wrong at your end?

I'm using firefox on android, but the problem is here:

Thanks! I fixed it and it should be scalable now.

The site works perfectly in Firefox on Android. The text content is perfectly readable without zoom, and zooming works to enlarge both the text and the embedded images.

What browser are you using where the zoom feature is blocked?

Answered in sibling with offending HTML.

I used to worked at Intel as a design engineer and I had to look through data-sheets to find the ICs with features and specs that I needed for the design.

Reply on news.ycombinator.com