This episode oozes all the things that makes Asianometry great. Expert, deep, quirky, silly, and interconnected.Thank you for what you do!

In the mid 80's I worked at a silicon design firm. Mostly 3 micron gate arrays. My boss and a really sharp engineer from the client company designed a modem chip. Their first silicon worked fine which elevated them past hero status to God of silicon design status. Mixed signal chip design is something like witchcraft. Thanks for another great video!

Ok, let's try to identify some of these images for fun. 0:06 A DC/DC converter module of some kind. Transformer and optocoupler in the middle of the board to isolate the primary (right) form the secondary (left). Could be for use in telco for converting 48 V to a local voltage like 5 V or 3.3 V for example. 0:13 Some analog chip produced by PMI (Precision Monolithics). Could for example be an opamp. 0:31 The title "analog delay" combined with delay stages taking opposite clock signals φ_1 and φ_2 points toward a BBD (bucket-brigade delay). This is an analog device delaying an analog signal by feeding it through a series of capacitors which each holds a sample temporarily before passing it on. I don't recognize the circuit. I would've loved for this to be either Serge's Wilson Analog Delay or Buchla's model 277 (modular synth devices) but it doesn't look like it. 2:09 As the title suggests, an analog multiplier circuit. What's neat about this circuit is that it's actually a logarithmic converters followed by a summer followed by an exponential converter. In other words, it turns a multiplication into an addition according to the laws of logarithms and exponentials: a*b=e^(log(a)+log(b)) 2:51 Looks like the same analog delay circuit as in the title card. Through the magic of reverse image search, this turns out to be an early 1976 guitar pedal prototype circuit which inspired MXR delay pedals. 3:05 The title cards for two previous videos. To the left, the board for a HackRF One, a SDR (software defined radio) which can be used to receive various radio signals. To the right, something that looks very much like a computer motherboard, with PCI or RAM slots. 4:27 Looks like a RF demodulator going into an AGC (automatic gain control) then into an amplifier feeding a builtin speaker. Ie a radio receiver. The negative voltage supply (positive ground) combined with liberal use of transformers, suggests a vintage circuit. 5:00 LM317 internal diagram. LM317 is a classic adjustable, linear voltage regulator. The schematic of the internal diagram is drawn in the datasheet. 7:18 Looks like a circuit for exercising your understanding of Kirchhoff's Law in school. Fun stuff. 10:52 A delicious cake, which I'm informed may be a lie. 12:30 Looks like a sawtooth wave generator. The second opamp is setup as a comparator, which will trigger the MOSFET and reset the phase when the voltage goes above 2.5 V, plus a little bit of positive feedback to encourage the opamp a bit to work as a comparator, which it's otherwise reluctant to do. Also, screenshots are hard. 12:44 Not a schematic, but just a note that it's difficult for AI to generate grids apparently. The lines are wobbly and the lines never seem to line up on both sides when they're obscured by some object. 15:18 Interesting. I wonder what this is. Two CPU/FPGA/whatever devices hooked up to memory, by the looks of it. And then IDC headers. This is probably some industrial or test equipment, like the digital portion of an oscilloscope.

The honor you show your parents is so wonderful

The complicity of analog design is worse when you include temperature sensitivities in the transistor and material performance. My old company (name withheld) included a Power On Rest circuit that gated power to internal logic so that it always started up in a known state. The circuit was updated in a routine design revision that passed all qualification tests across temperature and worked great in industrial grade applications, but came to a screaching halt when it was sold as an automotive product. Process variation of some lots allowed the temperature response of the POR to shift, locking the chip up when you turned it on in a narrow temperature window, A minor issue for a cell phone, but pretty painful if you are trying to unload VW's from a ship in the winter (the ECU wouldn't function). As you noted, analog design is an art, one where you have to know how all the paints mix and interact. Nice job on the presentation, I hope your father was able to retire happily.

As an analog/RF IC designer I can relate. About a dozen years ago when I was working at AMD our CAD group made an attempt to automate analog design to redesign chips shrinking to a smaller process node. It did this by interpolating the I-V curves to resize transistors. The results were laughably amusing and none of my IC design peers ever lost sleep worrying about design automation. Layout for analog circuits might be an even tougher nut to crack because an alogrithm would have to iterate on extracted simulation, layout, LVS/DRC checks, re-extraction, and back to simulation. Given the size of extracted netlists, I would expected the required hardware compute resources to require a supercomputer. LOL. But all of that was before AI. Fortunately, I'm close to retirement now so I expect to skate by just as your father did. Not so sure about the next generation of circuit designers, however ....

Jon - You don't have to eat the full slice of black forest cake. The real world is analog - you can have have a 1/2 slice... 1/4 slice... or just grab the cherry from the top. As always, a great video on a very complex topic.

Analog circuit design using discrete devices is an art by itself. Placing an analog circuit onto an integrated circuit is art at the grandmaster level.

I'm not normally down with the goofy tangents and memes in dry educational videos but you ride the line.

My perspective of 50 years of working in electronic industry is digital is a very narrow subset of analog. Resistance, and/or, impedance plus capacitance, and the one thing you left out in your talk is inductance. But you are correct and that it takes a few people with the artistry to do a good job in design.

13:02 AlphaGo was not actually trained on huge datasets. The reason it is capable of beating the world's best players with *novel* techniques is because it was not trained by watching humans play. Instead, it played against itself and gradually learned over millions (or more?) iterations while grading its performance.

All digital is analog - just depends on how deep you dive.. Thanks for what you do.

As someone who aspires to work as an analog designer this was really encouraging to hear.

It’s kinda interesting to think that even digital circuits are technically analog at their physical level. 😳

As an electronics repair tech for a large US manufacturer in the UK, I work on and use precision analogue electrical measuring instruments every day. I almost never gave any thought to the complex analogue designs inside the many many ICs used in this equipment. Being a designer of the circuitry in this high accuracy analogue equipment is a huge challenge in itself. The design engineers job is having to take into account parasitic capacitances, inductances and resistances. Having made a few analogue designs from discrete and IC components, I know how challenging some of these can be. I sometimes think it is all magic, and I have been in the industry since I left college in 1984. I take my hat off to those who design analogue circuitry on a microscopic level, and am glad to see you honour your father in this piece. Can I also just add that the sweet baked confection shown is a gateau, not a cake. Gateaus tend to have more than one layer of filling, usually a combination of buttercream icing and a fruit jam or compote. The main construction is formed of a light sponge. Son of an electrician and a baker.....

I used to be an analog and mixed mode ic designer. I had LOTS of fun. I especially enjoyed the challenges of simulating the circuits properly. And what a feeling when the first silicon arrived on the bench and it worked exactly like in the simulator! Of course sometimes certain behaviors of the actual chip remained a mistery...

10/10. Your style is art, too.

Thanks for being one of the best knowledge communicator out there dude.

Just to clarify, there's no metal in the center of the FinFET, that's silicon--an even worse conductor (semi-conductor in fact), which means even more resistance.

As an early career analog designer, I have to say that you generally got the design flow right, except that nowadays almost no one is using a paper and pencil to do anything significant. Usually things will be sized and played with in a simulator, experienced designers "have a feeling" about what sizing is going to work, and are usually right. The complexities of BSIM-BULK models (formerly BSIM6) means that doing anything on paper is fruitless, though there is some nice guiding principles in the EKV model. Reductions in supply rail headroom have also meant we have to do most things in weak inversion now, and that changes your current characteristic from quadratic to exponential, another weirdness that is different from what is taught in university. AI training really seems hard to achieve, though probably not impossible considering what LLMs are doing these days. But one of the key problems is that there are many criterion for "good" and so in order for a computer to optimise, this optimisation has to be set up in the outset. This means that two different analog designers might have very different goals with an assistant AI, one might care more about their area specification, another might be more focused on how they are going to achieve their dynamic range spec with the power consumption spec. As you said, it's a very high-dimensional space, I'm not sure how one AI tool can really guide you through all of that. That's to say nothing on how you are attaining this dataset to train on, where's that coming from? Also, who is qualified to do the annotation of data for a dataset? Lots of hard problems to solve in this domain.

15:30 "I hope it won't happen. Because analog is the real world, and its designing is an art" Amazing conclusion of video emotion, kinda touchy

If Bob Pease were still with us, he say, "What's all this AI stuff?"

Been part of several chip and board bring-ups. Getting the analog wrong through bad or lacking simulation cost us a lot of time and money.

Nice analysis. In my view, we can further divide the field into 'needs the best performance' and 'works well enough'. I think for now analog designers have job security for the high performance area. However, I believe that we'll see the growth of automated and AI tools for 'good enough' analog. Especially in the open source field, as it's a lot cheaper to test and develop. One of the criticisms of open source ASIC tools I've heard is that the older process sizes are not relevant, but in fact they are still very highly regarded by analog engineers for the reasons you outlined in your video. Additional interesting reading can be found here: "Open-Source and Autonomous Temperature Sensor Generator Verified With 64 Instances in SkyWater 130 nm for Comprehensive Design Space Exploration"

I worked as an FPGA digital designer with an office next to group that did mixed-signal chip design for imaging readout chips. This was a little different from some of the examples in the video because the imaging chips were and are much more analog than digital, and it was no secret that these mostly analog chip designers were the technical stars of the company. I had the privilege to be asked to sit in on one design review and was mightily impressed with the thought and skill that shown through in that presentation and discussion.

Analog design is the Gordian knot of design disciplines. AI as Alexander Invictus however will be denied a single sword to slice through it. It will have to unravel the knot every time. If it can, let everyone beware.

Didn't expect 'that' kind of numbers 1:30 in videos lol

As someone who has *tried* to use the Berkley Analog Generator (BAG) one of the main problems is setting the system up. First it is a python library (built by grad students) with lot's of dependencies, these are not always readily available on the operating systems used to run EDA software (*cough* RHEL 7 *cough*). After that hurdle is cleared, BAG needs a set of base layouts that the software can array copy (for lack of better words) next to each other. These base layouts are necessary to build up larger transistors with the flexibility to meet the design needs. These layouts are difficult to make due to the complicated design rules for current-gen and leading edge processes. Also, the work to build the layouts cannot be shared between processes as they are, in general, quite different from each other. All this to say, BAG has significant adoption costs associated with it.

I worked for years in the EDA SW team at HP/Agilent working with Test & Measurement teams. You are not kidding, analog design, especially very high frequency analog is freaking insanely complex & difficult...

My first analog circuit was a DC/DC converter with multiple inputs, single output to define the desired output voltage given the multiple inputs (it had power delivery limit, desired speed and temperature), it was designed to move a DC motor for a prototype car. Why did I made it analog? I dunno, I just loved the idea of making something different using something no one around me was able to even try to copy

Your presenting voice has gotten so much better dude, your work had been super thoughtful and now you're coming into perfection

I love your semiconductor videos, as I was a product engineer, we worked with both process engineers, design engineers, and test engineers.

Hi. I am engineer. Analogue design will be completely automated, if not already in some heavy projects, because the design reuse has reached its maturity early 2000, i.e. now there is only the need for advanced heuristics and optimization algorithms to achieve a middle range complex design of about 10000 transistors (we are not speaking of digital designs since these have pretty fixed rules(Lynn Conway anyone?). Unfortunately, the problem is that the new generation is not interested in analogue design, as being confident that digital systems will prevail or even they can outsource their analogue designs in the East. A bravo to Asianometry for this great presentation.

This must be my favorite episode so far! I especially loved the ending. And the cake, too

1:00 It is no longer limited to "comes from real world" QPSK, QAM are extensively used in real digital world to transfer data more than 1 bit / cycle - >10 bits per cycle. Not to mention SDR radios etc.

4:30 - Like the old transistor radio schematic !

Great stuff as always. There's been a change of tone compared to your earlier work which was more academic. I suppose I prefer that, but I am glad you are having more fun with these! Please keep this stuff going.

"Every idiot can count to one" Bob Wilder, the designer of the first mass produced OpAmp.

Love your videos, always nicely structured and explained well. Greeting from southern Black Forrest (Freiburg, Germany)

Working at an analog company we only considered ESD protection the black magic. Most analog design was fairly automated after proper modeling. Qualifying a new process was very in depth, and there were a few gotcha’s that popped up in the first designs with nearby devices or interconnects but those could be worked in design rules and coded into automated design tools. We would occasionally find a new problem in mature processes, but those learnings were quickly tested for in other processes and proactively prevented. We weren’t at 7nm, or 32nm, but the analog circuits were always larger geometry then the digital portions even in analog heavy designs.

Touching, funny, deep! Anyone with even a passing familiarity with circuit design can appreciate this! Thank you for brining this human element to a highly technical subject! Kudos and godspeed!

1) AI is trained on data from the Internet. 2) AI outputs data to the Internet. 3) Goto 1 ... Exponentially growing AI-feedback ... you now see how this ends :(

I only randomly view your videos, but it was cool to hear that your dad designed analog chips and that you were able to explore his realm with this video.

A similar thing that has always baffled me is analog mechanical computers like the fire control system in Iowa battleships. Which as far as I know remained a lot more accurate in it's firing solutions than many digital types that followed. And since it mixed inputs continually it also gave you solutions real time. The only not real time part was the human operator needed to feed the wind speed or some of the other inputs into the system. But other than that it was solving an analog equation with the given inputs.. mechanically. As a student of the binary age I've always thought that was really crazy that someone thought of doing things like that.

Those who aspires to be analog designer should have many first-hand experiences on discrete high frequency analog circuits design first in early age. You can experience many varied and weird parasitic behavior of analog circuits on such RF circuits. Familiarize yourself with many historic analog circuits design like radio, TV, classic amp, radio transmitter, op amp circuits. Study workings of the circuit carefully down to a resistor. Once you are accustomed and learned such strange and intricate nature of analog circuits, then study carefully circuit, layout, and floor plan of famous classic analog integrated circuits like LM741, NE555, LM324. etc. Compare SPICE simulation result and real circuit behavior. Know the difference of SPICE mode and real world integrated circuits. Try to understand why they are designed circuit and layout such way. You will get lots of insights from such classic designs.

Nice coverage of the topic! The core of the talk was about analog layout automation, yet there are many analog design automation methods (including ML based approaches) worth mentioning. Your channel has some of the best videos ever covering semiconductors technologies/manufacturing. It's great to know that all falls back to your father being an analog designer!

Yep. We had implemented everything in analog manner before this digital technology era. It was extremely hard if an implementation had to handle very high frequency signal. So, I feel that the analog tv systems were a miracle now a days. Anyway, thanks for your great shows.

bro knew what he was doing with numbers meme💀

As newbie analog layout engineer (not circuit design) the main time-consuming part for me with a new pdk is studying the DRM and making sure all the rule checks/requirements from circuit designer are cleared after the design and of course all that PEX/EM/IR/ERC issues and what not are met. My job sometimes feels like laying bricks following specific rules after the main designer (circuit designer) has designed the stuff for the building. I think the layout part could get automated at some time in the future (in fact some things are already done using scripts that does not need human intervention). Also, fun fact: Major companies usually outsource the manual jobs to 3rd world countries like India/Bangladesh. However, apple still maintains a very strict policy and their contractors have to be (I believe) physically present in their country/office. No wonder apple still rules the chip market with their efficient hardware-software combination, and their chips are so optimized whereas others are 'if it works it works'.

It might sound weird, but capacitors are analog. And tiny little capacitors make up RAM. We try and clear them, and recharge them, within tolerances, but it's definitely not a binary value between those two charge values.

As someone working in IC design, I congratulate you for the accuracy and clarity of the video! I'd just make a very minor correction: verification starts before, and is done in parallel with, the physical design. It only finishes after it, because it needs delay back annotation .

"delicious black forest cake"... "oh wait, where was I?"... I love this channel.

You left out power supplies, which are a major block of analog on soc parts. Analog capacitance and magnetics are physically big, so they take up a lot of space as do the deep wells. Rf design such as wifi cellular and Bluetooth also have considerable analog preprocessors, but are part of most soc's. The topology of analog can switch from unbalanced to balanced in integration, this driving up complexity. In the end, I don't hold out much hope for ai, but a combination of ai with quantum computing that can model multi dimensional parasitics, now we are talking.

Anyone here remember the OpAmp 555 timer?

Woah, it never occured to me that physical designers for digital logic lost jobs, I thought most of them just switched to working the CADs instead of doing that by hand.

This used to be a lot more manageable (not necessarily easier) when I started electrical engineering back in 1980...

This video is exactly what I needed after a talk about this with my mixed-signal circuit design professor

Yay! I love analog circuit design, though strictly as a hobbyist. I have discovered areas where analog circuits still perform better than their digital equivalents, for example fast PID controllers. The closing sentence sums up well my feelings about it being art.

The idea of an analog life form remaining the only means to design an analog chip would be poetic.

I am lucky to be an artist of this art. And I hope it won't get automated anytime soon.

Didn’t Analog Devices once use the catch phrase “we live in an analog world “?

I like how you kept the cake for as much time as possible on screen

excellent video about the difficulty of analog circuits. I'm hopeful someone can train a model to make this easier. I have to think TSMC is working on this problem internally.

As always, great video. But you forgot to mention the most exiting one: parasitic inductance. It really can do some fun stuff together with parasitic capacitance 😅 And for all the people that are impressed by the diagrams shown in this video: the white space… that’s were all the parasitics are hiding!

If you're ever in the NYC area you should try the black forest cake from Rudy's in Ridgewood.

Analog chip design is very tough. This is a great video that can be touched on multiple times. Safety critical devices pretty much only take analog inputs and as we innovate some of the new boards are not as good as the old ones from the 80's !!! We moved backwards in analog chip design !!

Love your channel big bro. I used to be more of a software type of guy, but you kinda nudged me into messing around with hardware alot lol. I might just get an FPGA and see if I can make my own stuff in the near future lol

Hell nah those numbers 💀

since 99% of electrical devices went from analog to digital, it would be great to have a video explaining where analog still has an edge over digital

Ah,yes, design a Butterworth filter for the following frequency range, with a Q TBD. Excellent overview Jon. But don't let my review go to your head, please.

I'm a senior engineer. I also see analog design as an art that needs time to master, which is being lost in a world were something that has more than 5 years is too old. Thank you for your kind words.

This channel is a true gem, thank you for these awesome videos!

nice :) I really struggle with the analogue parts of my projects :) I notice quite a movement to re-create old analogue chips like sound chips with FPGA emulation based on digital filters and some very creative bitstream shenanigans. That is open to AI approach too I think ? I recall some mobile robot gait generation approaches based on AI gen of bitstreams for FPGA ... with class D amps all sorts of oddness become possible on the analogue generation side.

The numbers... Yes... I recognise some of those numbers...

I still design with vacuum tubes and transistors.

1:32 I was not ready for that 😂

Great video man. Inspirational af thx

You need to interview guys like Doug Curtis, Dave Smith, Tom Oberheim, Dave Rossum... if you want to know about analogue IC design. Sadly Dave Smith passed last year but the others are still around and putting out products based on analogue circuitry.

As someone struggling and constantly befuddled by simple circuit designs... A lot things clicked watching this. 10/10 quality content and knowledge on this channel!

Can you elaborate on the issue with the proprietary PDKs? Looking at the GitHub for both align and magical they appear to be BSD licensed, so there shouldn’t be any issues there, do the PDKs have some kind of anti-OSS licensing associated with them?

I would love if you made a video on the Semiconductor supply industry. like who makes the machines that make the parts for the semiconductor industry. i work for a CNC dealership. Matsuura is a great company and they have this really cool metal 3D printer that also mills at the same time

I love this line "Digital world is all about numbers, a concept that human make up"

This is probably why the latest A17pro is not quite what we expected

Something not mentioned in the circuit layout part is the inability for algorithms to route circuits in a determinable amount of time. Most algos used in programs have a best/worst/average case (BigO notation) that is polynomial which mean time to complete is an exponent of the items to iterate over. Some algos are deterministic but some, like the travelling salesman problem, are nondeterministic and thus cannot predictably be solved in the most efficient way possible by a machine.

Having 40+ years of electronics repair and design under the belt, I found this video fascinating and enlightening. Thank you. 😊

Your videos never fail to reignite my passion for engineering, awesome stuff!

Great stuff as always

Astrus? Whoever naming that company is a genius! Imagine people introducing them ,may be on TV or stage : "This's Astrus."

I don't often fully understand all your videos but always find them very interesting & illuminating. 😎👍⭐⭐⭐⭐⭐ And occasionally very funny. 😂

Great work!

That’s tape worm joke is amazing

My first thought in this video, was correct selection from about millions of existing semiconductors in our world in designing analogue circuits boards. AI could help a lot in selecting these in function and low costs. This could speed up designing processes. // Would you do the same video in analogue design of elemental digital circuits components? => Design rules of transistors, gates, flip-flops, synapsis, neuronal circuits, ... ? Thank you for this video.

Another cracking episode. I have to do a bit of physics informed generative A.I. - which I find hard to do (I’m old) - so this is an interesting insight into an alternative application.

Thanks for analog art form review designing with pencil and paper

Quality explanations and great jokes all around quality video, top notch as always

Awesome episode John. Love analog ❤

if the road converges at some point, could you make a video on mixed signal design?

This video is wonderful way to show love and respect for your father.

constraint propagation algorithms [aka wavefunction collapse algorithm, similar to sudoku solving algorithm] seem like they might be well suited for this

Top of the line. Your channel is a treasure.