A group brainstorm can invent great stuff, but it's a fragile process.
-- John Larkin Highland Technology, Inc trk The cork popped merrily, and Lord Peter rose to his feet. "Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"
Here's my chip of the week:
Easy to use frequency-multiplying PLL, it does what it says on the tin. Unfortunately I don't think I have the ability to measure a one-sigma clock jitter of 25ps but that seems pretty good! And it's cheap
Incidentally here's some old-school salesmanship on a money-maker idea! why didn't I think of that. I feel like model trains are a growth industry in these times.
They charge a hundred bucks a piece for these DCC sound and motor decoders. Hundred bucks! Often more than the model locomotive you would put 'em in. Hmpf!
That tells us nothing true about Bill Sloman, it's just John Larkin projecting.
The thing with a grindstone in the middle is a 'mill'. Like, a diploma mill. Academia is more properly organized around a library, with noses in books and journals.
Bell Labs hired PhDs in groups, so they could talk to each other; that was quite productive.
That's cute, but we generally do clock bashing in an FPGA.
The TI LMX2571 is a serious synthesizer. We measured 1 ps RMS period jitter, which is our mesaurement floor.
-- John Larkin Highland Technology, Inc trk The cork popped merrily, and Lord Peter rose to his feet. "Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"
Has he ever posted a design? Has he ever hinted at having fun?
He has told stories about designing stuff decades ago, apparently mostly failures.
They also made sure that the PhDs talked to engineers and manufacturing people from Western Electric.
-- John Larkin Highland Technology, Inc trk The cork popped merrily, and Lord Peter rose to his feet. "Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"
I squeezed a flip-flop modified sine-generator and zero-crossing detector, into one of those GreenPAK mixed-signal PLAs, at 5 volts you can reliably clock them pretty fast if you don't expect to put a lot of complex functions between clock in and signal out. 60 or 70 MHz not a problem.
But feeding the internal ring counter at 8x the desired output frequency is annoying so just use the PLL to bump up the input clock 8x and you get the same output freq for the same input on the module and this makes the client happy.
tuff
aste on unneeded features/aspects. It is what every product should be.
t is often missing in even otherwise excellent products.
n too high a quality of English or that it was overly clear or that the ill ustrations were excessively detailed.
he next house. But I do need to be able to understand how to set it up.
they really should, but mostly they work "well enough" to get by. You can nearly always find products that are better than just "good enough", but t hey cost more when you find them. That is the commensurate "fair" price.
need is the path taken by many products to create profit. You can't expect someone to give up the profit motive.
o the people involved in creating and making them can also have nice things .
How much would you charge for a design that you made and now are producing in small numbers?
I know I charge a lot more than that!
-- Rick C. -- Get 1,000 miles of free Supercharging -- Tesla referral code - https://ts.la/richard11209
Here's an example of a designer's "talentstack" of the daily accumulation of wisdom of novel components with weekly favourites shared. There are millions of parts and it helps to know what exists so that when you need something, you know what exists and where to look.
The LMX2571 is indeed a high performance PLL and high price around $10 @10kpc +/-$2 depending on temp range with 1/f noise @ 10kHz offset =
-124 dBc/Hz with fmax = 1.344GHz
The ICS501 is indeed the lowest cost PLL at $1~1.5 (10kpc) in this performance range of sigma= 25 ps jitter up to 160 MHz (std temp) 140MHz (mil temp)
This leads to new(?) /talent stack/ for some to determine what test method and equipment can measure this phase noise or p-p jitter or use another method of delay lines and clocks to measure BER vs window delay with an inexpensive Phase Margin Analyzer approach. There is direct Convolution correlation between the ratio of Jitter and BER. This can also be done with time interval counters to measure 3sigma 6 sigma and
12 sigma. Or one can use high-end high price sampling scopes SA's or PMA'sThis is another example of building /test system skills/ with talents and not just use the target spec frequency and make the PLL run.
Trust but Verify is an essential Test Engineering Design skill to teach in how to verify what it takes to make a component meet it's specification, which will depend on layout, filtering and sometimes isolation. So prototype testing is essential.
( Although I can remember not following this rule in a major SCADA design in '76 among 3 EE's with 44 PCB designs. e.g. This was before UART's existed so one PCB was a discrete CMOS UART at 10 MBaud. Other's were Eddy Current Instruments and MC6800 controller and 192 Ch. I/O mux for switch and indicator panel. The problem was our schedule dictated, each person had to churn out a PCB design/wk with Mylar colored pencil layouts which went from paper to etch without protyping. I was stuck alone to debug and make it all work with modem boards, Robotics and micro/macro-code. So as you can imagine I was reworking the boards with a dozen instructions a day to get each to work. It was 6 mos later that the system was shipped. (CANDU Reactor Eddy Current Scanning Subsystem)
Lesson To learn in '77: Make a prototype 1st. (simulators didn't exist.)
Two, if you count consultants. ;)
Humph.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
We used our LeCroy 7 GHz scope to measure the jitter of the TI synth.
We used a different trick to do jitter measurements with a roughly 50 fs RMS floor.
The idea is to walk two edges across the clock and data inputs of an NB7V52 super-ECL flipflop and graph the average output. The actual jitter had contributions from other parts, so the flop itself is even better.
I did SCADA systems, for pipelines, without UARTS too!
-- John Larkin Highland Technology, Inc trk The cork popped merrily, and Lord Peter rose to his feet. "Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"
you couldn't see an area where you would put them to use?
That's not remotely true, and if John Larkin went to the trouble of reading anything that didn't make him feel better about himself he'd know it wasn' t true.
Piotr Wyderki's thread about a "Low power pulse generator" - where John Lar kin made a couple of posts - has a couple of my posts that include LTSpice .asc file text that describe a series original electronic circuit that even tually became a circuit that met Piotr's original specification - the last one is in on the 28th June.
By then Piotr had worked out how to do the job with even less current, so i t wasn't a useful exercise, but I did find it enjoyable.
Another bizarre misapprehension. I took five years over my Ph.D. project, b ut that was because I kept doing odd stuff that my supervisor didn't really understand - if he'd wanted to keep my nose to the grind-wheel he'd have g ot me to concentrate of areas that he knew something about, and computers a nd electronics weren't any of them.
The more likely reason that John Larkin won't hire another Ph.D. is that th ey are trained to do critical thinking, and John Larkin can't, and doesn't like being exposed to people who can.
-- Bill Sloman, Sydney
aper that is probably on-topic in a design group.
ing out new design has been ripping up what initially looked like promising approaches and starting over.
they talk about as a strategic mind-set - more emphasis on where you want t o end up than on any particular way of getting there.
his subject, or any other subject for that matter.
Not to you. The title of the paper is "A strategic mindset: An orientation toward strategic behavior during goal pursuit."
really overdoing it with authors too stupid to learn the applicable extant science, so they just make stuff up as they go along.
Fred Bloggs really doesn't seem to like the Proceeding of National Academy of Science. It's a fairly high prestige general science journal - there's n othing remotely phony about anything that gets through their peer-review pr ocess, and that does include checking that the authors have made proper ref erence to the existing literature.
his way.
By Fred Bloggs - which does suggest that he may be the one with the mental health problem. Phil Allison thinks that everybody else is autistic, which may reflects the same kind of problem.
fficacy of masks in preventing infection. I guess it escaped you they were using data from influenza studies.
Would that have made any difference to the results? Masks are a defense aga inst virus-loaded airborne droplets, and the nature of the virus is irrelev ant to their efficacy.
Fred does go in for a lot of magical thinking, and his conclusions are freq uently bizarre.
-- Bill Sloman, Sydney
per that is probably on-topic in a design group.
ng out new design has been ripping up what initially looked like promising approaches and starting over.
hey talk about as a strategic mind-set - more emphasis on where you want to end up than on any particular way of getting there.
Committees don't design anything. They may specify what a successful design might need to offer, or suggest what technology might form the basis for a successful design, but "a camel is a horse designed by a committee" does r eflect a tolerably correct - and popular - opinion.
Breaking up the design of a large system into manageable subsystems which c an be integrated into a coherent is a design problem, but not one that you' d expect a committee to solve all that well.
Only if you are designing at the John Larkin level of complexity. Real prob lems are more time-consuming.
-- Bill Sloman, Sydney
aper that is probably on-topic in a design group.
ing out new design has been ripping up what initially looked like promising approaches and starting over.
they talk about as a strategic mind-set - more emphasis on where you want t o end up than on any particular way of getting there.
his subject, or any other subject for that matter. This is just another pho ny paper from the National Academy of Sycophants, really overdoing it with authors too stupid to learn the applicable extant science, so they just mak e stuff up as they go along.
The Nat'l Academy of Mutual Admiration offered Feynman some honorific which he declined, not wanting to be associated with a self-congratulatory society whose chief function was conferring honors on one another.
Breaking out Shaw's "Man and Superman",
"When a man teaches something he does not know to somebody else who has no aptitude for it, and gives him a certificate of proficiency, the latter has completed the education of a gentleman." -- G.B. Shaw, "Man and Superman"
"He who can, does. He who cannot, teaches." --ibid.
his way. This is an even dumber cite than that last joke pretending to stud y the efficacy of masks in preventing infection. I guess it escaped you the y were using data from influenza studies.
"A fool's brain digests philosophy into folly, science into superstition, and art into pedantry. Hence University education."
"Every fool believes what his teachers tell him, and calls his credulity science or morality as confidently as his father called it divine revelation."
Grins, James Arthur
te:
paper that is probably on-topic in a design group.
frking out new design has been ripping up what initially looked like promisi ng approaches and starting over.
t they talk about as a strategic mind-set - more emphasis on where you want to end up than on any particular way of getting there.
this subject, or any other subject for that matter. This is just another p hony paper from the National Academy of Sycophants, really overdoing it wit h authors too stupid to learn the applicable extant science, so they just m ake stuff up as they go along.
ySounds sensible. Feynman was sufficiently well-known that he honoured any a ssociation that he condescended to join. The National Academy of Science do es have functions beyond self-congratulation - any member of the academy ca n get stuck with the job of refereeing and editing an article in their fiel d of competence which has been submitted to the Proceedings of the National Academy of Science, which can be a chore, and all national academies tap t heir members to review grant applications (which is a bigger chore). Self-c ongratulation is a pretty minor part of the job.
Shaw was a fine debunker. He'd have made short work of James Arthur, who pu shes out more bunk than you can shake a stick at.
-- Bill Sloman, Sydney
GPS is the best example of a system designed by committee that works and works great
Bobby, you're obviously not applying your metacognitive mindset - lashes with wet noodle and tick mark on your quarterly evaluation!
RL
There were people using satallites for location before GPS was invented; I helped a bit with the software. Some of the pioneers worked for ONI, Offshore Navagation Inc, a New Orleans outfit that used Raydist and Shoran to navigate boats to oil rigs and drilling sites.
-- John Larkin Highland Technology, Inc trk The cork popped merrily, and Lord Peter rose to his feet. "Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"
We have a responsible engineer for every design, but we always do group brainstorming and at least three design reviews. Several people can invent and design better than one, unless the management structure makes them worse.
Maybe the causality isn't that groups make things worse, it's that a lot of management does.
-- John Larkin Highland Technology, Inc trk The cork popped merrily, and Lord Peter rose to his feet. "Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"
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