Welcome, Anthony Wall!

• Anthony is a PhD student in the MCCI group at Tyndall, which is a research institution in Ireland.
• Why did companies like Intel and ADI choose Ireland?
• There was a recent history on 99% Invisible about Duty Free, the Shannon Airport and the first Special Economic Zones (which later inspired Shenzhen!). Definitely worth a listen!
  • In the 1930s, the flights from NYC to London needed refueling, so they set up the Shannon airport.
  • A man named Brenden O’Regan started doing some of the food there (and later invented the Irish Coffee — though the wiki page is contentious on the first one).
  • They implemented the first Duty free shop in an airport and later expanded the idea of a tax free zone to a fenced perimeter.
• As for chips, the limestone and lack of seismic activity means litho machines are very stable.
• There is chip industry in Shannon/Limerick, Cork, and Dublin (with different companies, focus areas)
• Like many other industries, there are hiring problems
• The ADC research world isn’t that large.
• Current ADCs allow a different design methodology and can allow for removing a transimpedance amplifier in front of an ADC circuit.
• But putting it all on one chip is difficult
• 1.2V core voltage rail on 65nm, so there are many power considerations
• Why measure current? Parasitic capacitance of each transistor is getting lower, so it gets easier to estimate “filling up buckets” with current.
• Ring oscillator
• Relaxation oscillator – sometimes these are shown as 3 inverters connected in series
• Want it to look like a sawtooth waveform. Dual slope ADCs also use sawtooth waveforms to capture information.
• What tools are available for tweaking the output on a chip design?
• Knows it’s roughly 70 ps to dump charge
• Currently they are mid precision (8 bits-ish) at MHz capture rates
• The chips were designed using the Cadence toolchain
• MPW is run by Europractice, which is similar to MOSIS
• The chip is 4×4 mm and certain high density runs get more. Anthony got about 100 chips back and it cost them 3.5K as an academic institutin
• The MPW was sent to TSMC
• There are different board level packaging options from Europractice
• Building test boards as a chip designer is a different experience. IC software is more constrained than PCB CAD software, even made by the same company like Cadence.
• P Cell – Parameterized cell
• The PDK from the fab is for the digital designers, but analog designers use it too.
• In the chip EDA space: there is Cadence and Synopsis
• Anthony added a graphic of a pair of “Shorts” to the metal layer
• LVS – Layout vs schematic is the method of checking between the two elements of chip design.
• Transistors are a 4 terminal device, you need to think about the body of the chip and how current will flow in the substrate. Chris and Anthony discuss whether this should be the first thing learned in the mental model of a transistor.
• Building higher level components on a design using re-usable blocks.
• Anthony needed to design the digital section of the chip as well, which written in verilog
• He had to downsample the data output on chip and deserialize it.
• Verilog gets synthesized to gate level (using the PDK) and then there is an interface between analog and digital sections
• You can separate different parts of the design by implementing “deep N-well“
• Advice from supervisor – “A PhD is like a religion, it means nothing to anyone else apart from you…you [need to] do it because you believe in it”
• During his PhD, Anthony has been teaching non linear circuits. A small pandemic silver lining is the change in teaching forma: notes handouts, lectures recorded by default (which can be paused), flipped classroom where they can go over home work in Falstad
• Get in touch with Anthony!
  • Twitter
  • His research site (with his contact info)
  • Direct email:  aw@anthonywall.ie

Chip Layout:

The 5 small sections down the middle are the ROSCs, the big block in the middle is the synthesised digital (mostly very expensive decoupling cap, with some digital that you can see as a messy glob in the mid-right), the bottom is a 100 ohm termination resistor & the clock buffer.

Die Shot:

On the die micrograph, you can see the density fill pattern we discussed (small squares). These are on the ~order of the wavelength of light, so they cause the diffraction pattern seen also. The bigger wires you can see are the power distribution network. You can also see the split between analog (left) and digital (right) on the IO ring to separate the power domains. If you REALLY zoom in, you can see different colour shading in the green regions (look in the ROSCS and CLK buffer); These are transistors.

The post #579 – ADC Chip Design with Anthony Wall first appeared on The Amp Hour Electronics Podcast.

• Dave had a recent video about selecting different op amps for the microcurrent (maintaining engineering!)
• ADI buying Maxim
• Maxim sampling policy
• Will there be a large amount of crossover parts?
• Microchip sent out a letter asking for better visibility into the backlog
• Boards with stackup
• Video about reviewing PCBs of forum member
• Chris borrowed an idea from past guest Luke Valenty about how to use pill shaped pads on the tinyfpga bx. This enables using a larger
• Process for PCBs
• “Lowest common denominator design” is the idea of choosing a PCB fab that has a very small space/trace, but only needing it for the
• smallest chip.
• CSP – Chip Scale Package
• “Putting the EV in EEVblog” (looking at electric vehicles)
• Dave bought a teardown report of the BMW i3 on Leandesign.com and it’s awesome.
• Forensic teardowns
• Intel video inside the chip fab
• We were sad to hear that Grant Imahara passed away last week. Watch his former co-host Adam Savage talk about memories of Grant.

Image from this video about fractions

The post #502 – Lowest Common Denominator Design first appeared on The Amp Hour Electronics Podcast.

Welcome Dr Thomas (Tom) Lee of the Microwave Integrated Circuits Lab (SMIrC) at Stanford University!

This episode is sponsored by Rohde and Schwarz. Check out AskAnEngineer.us for more info about their value line test equipment.

• Tom is friends with two past guests, Jeri Ellsworth and Kent Lundberg
• Tom owns a LOT of scopes (200 or so)
• First scope was a Heathkit
• The Tek 485 had nice user design
• “I didn’t like an intermediate layer.”
• John Addis and Wink Gross designed the important parts of the 485
• The 485 added a superfast square wave to the front panel important for calibrating a 350 MHz scope
• Protection circuits
• Tom got started in electronics fixing TVs
• He then went to work for the founders of Wavetek (but not directly for the company) with people like Joe Deavenport
• Tom went to MIT and worked under Jim Roberge (check out the video series where Jim is lecturing on-camera)
• He proposed a thesis that was the world’s first integrated CMOS radio
• Marvin Minsky
• “The thesis doesn’t change the world…it changes you”
• CMOS was considered crap, was mostly used for wristwatches and calculators
• Other types of MOS and BJT circuits were considered to be much better.
• Tom used MOSIS, the IC bundling service mentioned on this program before.
• Didn’t have PDKs
• Magic from Berkeley allowed Tom to see the DRC errors as they happened.
• He ended up building an FM radio…without any inductors!
• Made gyrators into inductors
• Moved to Analog Devices where he learned a lot from Barrie Gilbert and Paul Brokaw
• Moving back to California and went to work for a startup RAMBUS
• Stanford wanted someone to do RF and give a first class on RF chip design
• Tom started in 1994 and started the first microwave IC lab.
• Tom and his grad students created the first GPS CMOS receiver
• Used to be 1 GHz and above is microwave
• Many of Tom’s students are (truly) seeing Maxwell’s equations for real for the first time
• What are the mental models?
• Tom said he “inflicts history on students”. This is also in the early chapters of Tom’s book, Planar Microwave Engineering
• Maxwell didn’t use vector calculus, he used quaternian form.
• Every course Tom teaches has a lab, including his undergrad lab which involves copper tape and making a radio.
• A lot of faculty have never built stuff
• He is now working with students on mmwave and 5G (because that’s where a lot of the research dollars are right now)
• Beamforming to get aggregate bandwidth
• Printed electronics for power delivery, serving devices that are in the mW level not the W level
• Feature sizes of CMOS
• Tom is on the board of Xilinx
• Tom is taking a year sabbatical and working on a book about instrumentation
• He hopes to ask many of the creators about the secrets inside the test equipment he often is reverse engineering
• Jim Williams told him to buy a rubidium clock (standard) at a flea market.
• Worked at DARPA, where his office funded development of a chip scale atomic clock
• That chip subsequently released a bit of smoke in the space station…
• Read more about Tom’s research on his group’s website

The post #459 – An Interview with Tom Lee first appeared on The Amp Hour Electronics Podcast.

Welcome Kieran O’Leary, principal of Mixed Signal Systems!

• Chris knows Kieran via the consulting forum. You can apply to join here.
• Went to school in Cork, Ireland
• Hard IP inside of FPGAs started on the Virtex2 pro
• Now they’re doing FPGA next to RF sections (which from a noise perspective is crazy)
• FAEs vs AEs
• “Applications engineers are responsible for shepherding the design from development into the customers hands”
• AEs understand the need for trust with a customer
• Kieran has worked at Xilinx, ADI and Wolfson
• “If your client is pushing through a million units a week, it’s a statistical certainty that any problem in the silicon is going to surface”
• Sometimes you don’t want the cutting edge silicon
• “You want to be on the leading edge but not on the bleeding edge”
• Making eval and dev kits at chip companies
• Was it more about making a breakout board? Or something interesting?
• Walking through silicon coming from the fab
• Hand carrying the silicon back from the packaging facility
• Pinouts move sometimes!
• Custom sockets are expensive to make.
• THD measurements might look poor if the connection between the socket and the device look bad
• Boards for the general public need better supporting collateral
• In 2012, Kieran decided to move into consulting
• He often helps clean up technical debt on the hardware side of things
• Things to watch out for in Signal Integrity
• “Current flows in loops, either you or Maxwell will determine the return path”
• Dr Howard Johnson on The Amp Hour
• Split ground planes
• “There’s nothing foolproof to a sufficiently proficient fool”
• Troubleshooting EMC problems
  1. Check the values on the schematic
  2. Take a nearfield probe and see what you see
  3. Look for common culprits
     1. See where signals are jumping over a split plane
     2. Termination resistors in the wrong place
•  Helps to add placeholders for future filters and termination
• Maxwell was Scotish, so there is a statue commemorating him. There is a Maxwell museum, as well!
• Follow Kieran on Twitter!
• His company Mixed Signal Systems is also on there.
• Kieran helped run the EMC Compo 2015 – The 10th International Workshop on the EMC of Integrated Circuits
• 12th int’l is coming up in China

The post #452 – An Interview with Kieran O’Leary first appeared on The Amp Hour Electronics Podcast.

Welcome Joe Bamberg, Lead Hardware Engineer at Sense

• Joe went to school at Miami, studying for pre-med.
• After a masters degree in EE, he ended up at Analog Devices (ADI) working on Energy metering ICs.
• Lyric labs
• Most meters are electromechanical, using moving parts to measure current via the Right Hand Rule. This then turns a wheel which measures “impulses per kwh”
• Past guest Larry Sears worked connected (gas!) meters.
• The first meters that weren’t manually read used IR.
• Different generations of smart meters moved from measuring active power (Watt hour meter) to reactive power (VAR / apparent power / power factor / Line sag)
• Most homes have a power factor of 1 because of the primarily resistive loads.
• The onboard “filter based metering” used Hilbert filtering (transforms)
• Measuring current
  • CT – current transformer
  • Shunt
  • Rogowski coil
• Joe worked on parts like:
  • ADE7755
  • ADE7858
• After ADI he ended up at Qualcomm / Pixtronics working on MEMS display technology. It used an IGZO (indium gallium zinc oxide) process
• The Sense is primarily in the US and Canada right now, measuring split phase, 120V power.
• Founder Mike Phillips has lots of experience with speech recognition (and disaggregation), which translated to the signal processing on Sense.
• Chris asked about if Sense shuts down, Joe later updated that this was addressed on the Sense blog.
• Internally there is a front end, isolated flyback, iMX7 and WiFi. It runs a custom distro of Linux.
• It’s not just for monitoring power, it also monitors events. For instance, one of Joe’s co-workers got a message “Your sump pump is kicking on”
• The solar version ships another set of CTs
• Edge processing (computing)
• There are a bunch of regulations NEC, UL, FCC, CE, CISPR
• Bolt helped with the initial mechanical design.
• It’s small because of the variable size of installation cavities.
• Have more questions? Find Joe on Twitter as @thejoebamberg

The post #371 – An Interview With Joe Bamberg first appeared on The Amp Hour Electronics Podcast.

• Amazon is getting into the IoT cloud business.
• Chris views this similarly as Electric Imp with the server and the client (the small battery powered device). Brandon was on the show talking about it.
• It’s not always just pushing commands down to a battery device. Sometimes the devices publish to graphing services like analog.io/imp.guru.
• Adafruit and Sparkfun also have publishing services, which Dave thinks will be hopeless against a service like Amazon.
• Amazon has a set of development boards that already work with the service.
• While Dave doesn’t think the second place people will work, he has uploaded videos to Daily Motion (vs YouTube) as a hedge in case they ever usurp the big dogs.
• Pirate Electronics is a nice electronics educational program online. However, they recently wrote about why they chose Python for microcontrollers (which aren’t actually micros), which seems like they are optimizing for the wrong thing.
• National is making some older parts EOL, though it may be that it’s only certain versions of chips (packages, lead free, etc). The LM567, a tone detection chip, is on the list of EOL.
• Dave asks about how a die shrink works at a fab. 
• Analog and Maxim Integrated may soon be….integrated. What will we call them, Maximalog?
• There have been over $110B in mergers so far this year.
• Dave remembers how Maxim released new databooks consistently. Referencing the parts contained within required the cross reference in the index. 
• Parts.io is now fully open to the public, no registration required. Chris was also on The Sparkgap Podcast talking about how to find op amps (and Parts.io as an extension of that). 
• The conference that Chris is helping set up (The Hackaday Superconference) is now open for registering for tickets.
• There will soon be a 19 hour flight from Perth to London. Dave recalls traveling 48 hours (with time changes) to get to Europe.
• You can communicate with the Amsat Fox-1, which is now in orbit. 
• Chris is back on the robots train. What won’t automation and robotics do into the future? 
• The Skarp had funding suspended on Kickstarter. What does this say about future projects that have a “prototype”.

The post #271 – Amazon Moves In, Dave Says Run first appeared on The Amp Hour Electronics Podcast.

Welcome Andreas Olofsson of Adapteva!

• Adapteva are the makers of the stackable supercomputer called the Parallela. This uses the Epiphany chipset, which is the main product of Adapteva.
• The company is located outside of Boston.
• Before starting Adapteva, Andreas was a lead designer on the Analog Devices TigerSHARC DSP.
• The Epiphany architecture allows for rapid calculation of paralleled tasks.
• The Parallela has 3 tools on board, which are required for any good supercomputing system.
  • A micro for the OS and easy interfacing and troubleshooting.
  • A high performance coprocessor for handling heavy duty calculations (with GFLOPS/W)
  • Flexible logic for handling interfacing and offloading other tasks from the main processor.
• The reason that licensing the Epiphany platform outright likely won’t work is the scale of SW add-ons that is required by industry.
• To get started with the Parallela
  1. Buy the board (it is carried on Amazon)
  2. Download the SDK
  3. Join the community to chat with others and learn about existing projects.
• There have been some interesting uses so far:
  • Drone video footage processing (on the drone!)
  • Matrix math
  • FFTs
  • Password cracking – bcrypt
• This all started back in Fall 2012 with a Kickstarter. 
• The Adapteva blog is great as well. Chris enjoyed this post about Semiconductor Economics 101.
• Funding has been difficult as most VCs don’t like investing in chip companies.
• Andreas is always interested in partnerships. You can reach Andreas on twitter under his handle @Adapteva. You can also write to him at support at adapteva.com.

The post #254 – An Interview with Andreas Olofsson – Adapteva’s Ampliative Abacus first appeared on The Amp Hour Electronics Podcast.

• Hank graduated from University of Illinois in 1974
• He then worked at National Semi 2 months before there was a huge layoff. Other companies followed with similar fates, due to the timing of the job market.
• He has been at Analog Devices for 25 years now! Awesome!
• He started in field applications but now works in central applications, developing writings and seminars.
  
• The most famous of which is the Linear Circuit Design Handbook, one of the best (free!) resources available online for analog. Hank was the editor and there were other contributors as well. They called the book, “the seminar that never was”.
• Another great (free!) resource is the ADI’s “Op Amp Application Handbook“, Walt Jung, Editor.
• Hank works out of the San Jose office and his home office, but also travels around to train people. He’ll let us know when he’s doing his next public seminar.
• Yet another awesome resource (and something that got integrated into the Linear Circuit Design Handbook) is an app note called, “Staying well grounded“
• Both that article and an article by Henry Ott about split ground planes (Henry was a former guest of the show) helped Chris get through many design problems.
• Hank suggests to “Think like an electron”.
• While working on a particularly difficult verification circuit, Hank had to build a 3500W linear amplifier(!!).
• Hank puts the “Low vs High Frequency” division at about 10MHz-100MHz. Basically when you need to start worrying about EMI.
• Integration continues to increase in analog components. Chris recalls the ADuCM350 discussed last week.
• In order to keep advancing technology, we need more package changes. Really this means we need to be able to access I/O on silicon.
• Hank maintains his audio hobby, including his work as a musician. He built an outboard DAC with a “ludacris fringe” — a 7 pole filter for the DAC output. Wowza!
• The precursor to Hank’s “Staying Well Grounded” was Paul Brokaw’s AN202, “Making things go right for a change“
• Many people don’t understand the mechanical to electrical conversion process, as in an accelerometer. Hank says they measure zeptofarads.
• When looking at ADCs, some look at SNR and some look at ENOB.
• Hank doesn’t work much with IBIS because he stays in the relatively low frequency realm.
• The newere tech is “evolutionary vs revolutionary”. But that means consumers will get more for less (and faster!). Chris likes the isolators like the ADUM2401.
• PLLs are getting faster too…now running around 18 GHz!
• Hank’s next series of articles will be about phase response filters.
• This will appaear in the Analog Dialogue, an awesome newsletter about all things analog (a little bit of marketing, but its bearable). There are also very valuable archives.
• If you’d like to reach Hank, you can email him at hank.zumbahlen@analog.com

Thanks so much to Hank for talking to us on the show this week. It’s always great to get analog gurus with their war stories on the show! Also, thanks to Michael Ossmann (@michaelossmann) for joining us again!

The post #185 – An Interview with Hank Zumbahlen – Zoppa Zumbahlen Zateticism first appeared on The Amp Hour Electronics Podcast.

• • Chris finally got a chair and wowsa does it make a difference!

• Finding parts online can be tough with distractions, apparently extended internet use can affect the brain. What’s a datasheet hunter to do?
• If you’re still a USENET junkie, Dave is on the sci.electronics.design (accessible through Google Groups).
• Shoutout to Junko Yoshida for some of the great articles she writes. Really enjoyed the piece on “The Land of the Rising Silence” when she visited Japan.
• Students in the US can get Amazon Prime for a year (Chris got 1-night shipped his chair for $4). Dave dislikes how they won’t ship anything but  books to Oz.
• Dave has been looking for the lowest power 16+ bit A/D converter he could find. All told he found 2412 from over 24 different companies. Crazy!
• COTW: The AD7691 from Analog Devices.  18 bits and only 108uW @ 8kHz. Wowsa!
• Speaking of low power, our friends from Touchstone Semi have been getting some press from their initial announcements. They’re 2nd sourcing components from Maxim IC…hopefully without any issues.
• Design Spark has a new plugin for their free CAD software that allows 3D models (incorporated in version 2) to be exported to Google Sketchup. Cool!
• With the CADspan plugin for Google Sketchup and 3D printing, it’s conceivably possible to make an entire prototype for <$100.
• Dave looking for preferences on CAD packages for future OSHW projects. Your opinion?
• Have there been any large-scale open source hardware projects? Chris and Dave can’t think of any.
• Obama announces robot initiative. Only $70 million but the idea is great. Won’t be creating jobs anytime soon though!
• This Day in Nerd History:
  • June 26th (oops!) — Maurice Wilkes was born. Founding father of many microcomputing principles and techniques (in the ’40s, no less!)
  • June 27th — The inaugural run of the first U.S. passenger train to use electric locomotives.
    June 28th — Milan, Italy inaugurated the first central European electricity power station.
• Lightning Round:
  • Company gets approval to store your Facebook data for future employers to look at. Yipes!
  • The patent system in the US gets approval in the house. If signed into law, it’d be “First to file” instead of “First to invent’.

That’s all for this week. Be sure to leave us some comments and find us on Twitter or Facebook!

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