IC Packaging – #37

Packaging engineers are the unsung heroes of the IC world. Packaging Expert Jesse Rebeck sits down and explores the complexities of IC packaging.

The unsung heroes of the IC world – packaging engineers!

The pictures I promised:

The UXR Amplifier Fanout Package:

UXR_Amplifier_FanOutPackage

Bert Signal Conditioning Hybrid Packaging:

BERT_SignalConditioning_HybridPackage

UXR Data Processor Flip Chip Packaging:

UXR_DataProcessor_FlipChipPackage

Space Technology – #36

Space requires new technologies. Much like the space race of the 1950s, engineers are feverishly working to gain a competitive advantage. Mark Lombardi sits down to explore rad hardening, thermal vacuum chambers, space mining, CubeSats, and battery technology.

Hosted by Daniel Bogdanoff and Mike Hoffman, EEs Talk Tech is a twice-monthly engineering podcast discussing tech trends and industry news from an electrical engineer’s perspective.

Space requires new technologies. Much like the space race of the 1950s, engineers are feverishly working to gain a competitive advantage. Mark Lombardi sits down to explore rad hardening, thermal vacuum chambers, space mining, CubeSats, and battery technology.

 

Mark Lombardi – 25 years at HP/Agilent/Keysight. He worked for RT logic for a few years, where he got into space.

2:00 – Your odds of survival getting to space are better than getting to the top of Everest.

2:30 – Space mining from the Asteroid belt has the potential to create the worlds first trillionaire.

3:20 – We need to establish manufacturing in space. For example, what if you manufactured satellites on the moon instead of on earth?

4:00 – The main driver is price-per-pound

6:10 – The Space Force – it sounds a little silly at first but is very reasonable when you take a closer look.

7:45 – How do you test objects bound for space?

8:30 – Space is transitioning from government-only to commercial. Businesses are starting to explore how to add value to society and make a profit from space.

9:15 – Phased arrays, reusable rockets, LEO satellites are all changing space technology.

10:00 – Low earth orbit satellites have much lower delay. Geosynchronous satellites have a 250 ms propagation delay.

This has interesting implications for 5G – that 250 ms latency is too long for 5G requirements. So, LEO satellites are what will be used.

12:00 – Using LEO satellites will be deployed in force instead of as singles, as mentioned in the Weather Cubesat podcast.

13:45 – Ghana launched their own satellite, which is a huge step. They eventually won’t be dependent on others for their space access. And, they can do specialized things for reasonable prices.

15:00 – Announcements – we haven’t podcasted in a long time, sorry! We are switching to 1x per month

16:45 – Radiation hardening for electronics, sometimes called electronics hardening. Historically, you had to plan for a long life in a satellite. Now, you don’t have to.

17:30 – It’s also hard to get a rad hardened cutting-edge technology.

18:00 – LEO satellites get less radiation, so it’s less of a problem. And, since they are cheaper, you can build in an expected mortality rate.

19:00 – You can also rev hardware faster, allowing you to use newer technology. Think about imagers, the technology has moved a long way in seven years.

19:55 – Space is cold. Space is a vacuum. So, to test our gear you have to reproduce that on earth. To do that, we use special chambers.

20:50 – Thermal vacuum chambers (T vac) are used to test space objects. Automotive parts are actually very resilient to temperature changes and can be leveraged into space designs.

21:30 – What happens to electronics in space? The vacuum is a bigger challenge than the temperature changes.

23:30 – To get more bandwidth, we have to increase frequency. This leads to attenuation in the air and in cables. Some designers are switching to waveguides.

25:00 – With modular test equipment, you could potentially have test gear that can survive in space.

27:00 – What is the current and projected size of the space industry?

28:10 – What batteries are used in space? What factors into battery decisions? – Lithium ion batteries work well in space, and are used when we can charge them with solar energy.

28:40 – Deep space exploration uses all sorts of obscure battery technology.

29:10 – Electronic propulsion

30:05 – Over 150V, things get interesting. The breakdown voltage is different in space than it is on earth. So, designers have to be very careful.

New 110 GHz Oscilloscope – UXR Q&A #35

Brig Asay, Melissa, and Daniel Bogdanoff sit down to answer the internet’s questions about the new 110 GHz UXR oscilloscope. How long did it take? What did it cost? Find out!

Brig Asay, Melissa, and Daniel Bogdanoff sit down to answer the internet’s questions about the new 110 GHz UXR oscilloscope. How long did it take? What did it cost? Find out!

 

Some of the questions & comments

S K on YouTube: How long does it take to engineer something like this? With custom ASICs all over the place and what not…

Glitch on YouTube: Can you make a budget version of it for $99?

Steve Sousa on YouTube: But how do you test the test instrument?? It’s already so massively difficult to make this, how can you measure and qualify it’s gain, linearity etc?

TechNiqueBeatz on YouTube: About halfway through the video now.. what would the practical application(s) of an oscilloscope like this be?

Alberto Vaudagna on YouTube: Do you know what happen to the data after the dsp? It go to the CPU motherboard and processed by the CPU or the data is overlayed on the screen and the gui is runner’s by the CPU?

How does a piece of equipment like that get delivered? I just don’t think UPS or Fedex is going to cut it for million+ dollar prototype. It would be nice to see some higher magnification views of the front end.

Ulrich Frank:mNice sturdy-looking handles at the side of the instrument – to hold on to and keep you steady when you hear the price…

SAI Peregrinus: That price! It costs less than half the price of a condo in Brooklyn, NY! (Search on Zillow, sort by price high to low. Pg 20 has a few for $2.7M, several of which are 1 bedroom…)

RoGeorgeRoGeorge: Wow, speechless!

R Bhalakiya: THIS IS ALL VOODOO MAGIC

Maic Salazar Diagnostics: This is majestic!!

Sean Bosse: Holy poop. Bet it was hard keeping this quiet until the release.

jonka1: Looking at the front end it looks as if the clock signal paths are of different lengths. How is phase dealt with? Is it in this module or later in software?

cims: The Bugatti Veyron of scopes with a price to match, lol

One scope to rule them all…wow! Keyesight drops the proverbial mic with this one

Mike Oliver: That is a truly beautiful piece of equipment. It is more of a piece of art work than any other equipment I have ever seen.

Gyro on EEVBlog: It’s certainly a step change in just how bad a bad day at the office could really get!
TiN: I have another question, regarding the input. Are there any scopes that have waveguide input port, instead of very pricey precision 1.0mm/etc connectors?
Or in this target scope field, that’s not important as much, since owner would connect the input cable and never disconnect? Don’t see those to last many cable swaps in field, even 2.4mm is quite fragile.

User on EEVBlog: According to the specs, It looks like the 2 channel version he looked at “only” requires 1370 VA and can run off 120V.  The 4 channel version only works off 200-240V

The really interesting question: how do they calibrate that calibration probe.
They have to characterize the imperfections in it’s output to a significantly better accuracy than this scope can measure.  Unless there’s something new under the sun in calibration methodology?

Mikes Electric Stuff‏ @mikelectricstuf: Can I get it in beige?

Yaghiyah‏ @yaghiyah: Does it support Zone Triggering?

User on Twitter:

It’ll be a couple paychecks before I’m in the market, but I’d really be interested in some detail on the probes and signal acquisition techniques. Are folks just dropping a coax connector on the PCB as a test point? The test setup alone has to be a science in itself.

I’d also be interested in knowing if the visiting aliens that you guys mugged to get this scope design are alive and being well cared for.

Hi Daniel, just out of curiosity and within any limits of NDAs, can you go into how the design process goes for one of these bleeding-edge instruments? Mostly curious how much of the physical design, like the channels in the hybrid, are designed by a human versus designed parametrically and synthesized

USB 3.2 + Why You Only Have USB Ports On One Side of Your Laptop – #32

USB 3.2 DOUBLES the data transfer capabilities of previous USB specifications, and could mean the end of having USB ports on just one side of your computer. Find out more in today’s electrical engineering podcast with Jit Lim, Daniel Bogdanoff, and Mike Hoffman.

USB 3.2 DOUBLES the data transfer capabilities of previous USB specifications, and could mean the end of having USB ports on just one side of your computer. Find out more in today’s electrical engineering podcast with Jit Lim, Daniel Bogdanoff, and Mike Hoffman.

 

1:00
Jit is the USB and Thunderbolt lead for Keysight.

1:30
USB 3.2 specifications were released Fall 2017 and released two main capabilities.

USB 3.2 doubles the performance of  USB 3.1. You can now run 10Gb/s x2. It uses both sides of the CC connector.

In the x2 mode, both sides of the connectors are used instead of just one.

4:00
The other new part of USB 3.2 is that it adds the ability to have the USB silicon farther away from the port. It achieves this using retimers, which makes up for the lossy transmission channel.

5:00
Why laptops only have USB ports on one side! The USB silicon has to be close to the connector.

6:30
If the silicon is 5 or 6 inches away from the connector, it will fail the compliance tests. That’s why we need retimers.

7:15
USB is very good at maintaining backwards compatibility

The USB 3.0 spec and the USB 3.1 spec no longer exist. It’s only USB 3.2.

The USB 3.2 specification includes the 3.0 and the 3.1 specs as part of them, and acts as a special mode.

9:00
From a protocol layer and a PHY layer, nothing much has changed. It simply adds communication abilities.

9:55
Who is driving the USB spec? There’s a lot of demand! USB Type C is very popular for VR and AR.

12:00
There’s no benefit to using legacy devices with modern USB 3.2 ports.

13:45
There’s a newly released variant of USB Type C that does not have USB 2.0 support. It repurposes the USB 2 pins. It won’t be called USB, but it’ll essentially be the same thing. It’s used for a new headset.

15:20
USB Type C is hugely popular for VR and AR applications. You can send data, video feeds, and power.

17:00
Richie’s Vive has an audio cable, a power cable, and an HDMI cable. The new version, though, has a USB Type-C that handles some of this.

18:00
USB 3.2 will be able to put a retimer on a cable as well. You can put one at each end.

What is a retimer? A retimer is used when a signal traverses a lossy board or transmission line. A retimer acquires the signal, recovers it, and retransmits it.

It’s a type of repeater. Repeaters can be either redrivers or repeaters. A redriver just re-amplifies a signal, including any noise. A retimer does a full data recovery and re-transmission.

21:20
Stupid Questions:
What is your favorite alt mode, and why?
If you could rename Type-C to anything, what would you call it?

 

 

 

Weather CubeSats – #30

We have surprisingly little knowledge of weather. When specifically does a cloud rain? How do these clouds form? We don’t have good answers to these questions. Getting those answers is an electrical engineering problem – one that a handful of professors and NASA are solving with CubeSats.

Historically, we’ve used large satellites and ground-based systems to track weather patterns, but CubeSat arrays are becoming a viable option. In this episode, Daniel Bogdanoff sits down with the leading researchers in this area to hear about the challenges and advancements being made in this area.

We have surprisingly little knowledge of weather. When specifically does a cloud rain? How do these clouds form? We don’t have good answers to these questions. Getting those answers is an electrical engineering problem – one that a handful of professors and NASA are solving with CubeSats.

Historically, we’ve used large satellites and ground-based systems to track weather patterns, but CubeSat arrays are becoming a viable option. In this episode, Daniel Bogdanoff sits down with the leading researchers in this area to hear about the challenges and advancements being made in this area.

Interviewees:

Charles Norton – JPL Engineering and Science Directorate POC
Joel T Johnson – ECE Department Chair and Professor at The Ohio State University
Christopher Ball – Research Scientist at The Ohio State University
Dr. V. Chandrasekar (Chandra) – ECE Professor at Colorado State University
Eva Peral – Radar Digital Systems Group Supervisor at JPL

Agenda

Intro

Space is changing. Big, expensive satellites used to be our only option. But, as you’ve probably heard on this podcast, when it comes to technology the world is always shrinking – and satellites are no exception. And that’s what we’re exploring today, specifically, the way cubesats (miniature satellites) are revolutionizing the way we look at earth’s weather.

Hi, my name is Daniel Bogdanoff, and welcome to EEs Talk Tech. In our last episode, I brought you all along with me to Wallops flight facility in Virginia for a rocket launch. It was an eye-opening experience for me, and I wanted to cover more than was reasonable for a single episode. So today, we’re blending the style of last episode and our standard interview-style podcast. I sat down with some EE professors from Ohio State University and Colorado State University to talk about their cube sat projects – all of which monitor weather using radiometers or radar and are pretty high tech.

I also apologize in advance for the background noise during the interviews, I’ve done the best I can to minimize the noise and voiceover parts I feel are hard to hear. I’ve also used clips from their NASA TV presentations wherever possible.

Let’s get started, and hear a little bit about the advantages of CubeSats from Charles Norton.

Advantages of CubeSats [1:05]

Cubesats are nice not just because they’re cheaper and smaller. Thanks to the miniaturization of new technologies in both their physical size and their power consumption, we can deploy more systems, more rapidly, and at a lower cost. They also require smaller teams to develop and operate, and can even have higher measurement accuracy than existing assets.

CubeRRT [3:51]

At its core, CubeRRT is all about making radiometry measurements better by processing out man made emissions – leaving only the earth’s natural emissions.

From NASA: “Microwave radiometers provide important data for Earth science investigations, such as soil moisture, atmospheric water vapor, sea surface temperature and sea surface winds. Man-made radiofrequency interference (RFI) reduces the accuracy of microwave radiometer data, thus the CubeSat Radiometer Radio Frequency Interference Technology Validation (CubeRRT) mission demonstrates technologies to detect and remove these unwanted RFI signals. Successful completion of the CubeRRT mission demonstrates that RFI processing is feasible in space, high volumes of data may be processed aboard a satellite, and that future satellite-based radiometers may utilize RFI mitigation.”

TEMPEST-D [8:00]

Instead of having a big satellite sitting in geosynchronous orbit, an array of CubeSats can be put in orbit such that they each pass over the same spot at set intervals. With some careful calibration, differences in the measurement equipment gets normalized out and they get good weather data.

From JPL: “TEMPEST-D is a technology demonstration mission to enable millimeter wave radiometer technologies on a low-cost, short development schedule. The mission … reduces the risk, cost, and development duration for a future TEMPEST mission, which would provide the first ever temporal observations of cloud and precipitation processes on a global scale.  For TEMPEST-D, JPL developed a mm-wave radiometer payload that operates at five channels from 89 to 182 GHz and fits in a 4U volume within the 6U CubeSat.”

RainCube [11:47] & the Origami Antenna

From JPL: “RainCube (Radar in a CubeSat) is a technology demonstration mission to enable Ka-band precipitation radar technologies on a low-cost, quick-turnaround platform. RainCube developed a 35.75 GHz radar payload to operate within the 6U CubeSat form factor. This mission will validate a new architecture for Ka-band radars and an ultra-compact lightweight deployable Ka-band antenna in a space environment to raise the technology readiness level (TRL) of the radar and antenna from 4 to 7 within the three year life of the program. RainCube will also demonstrate the feasibility of a radar payload on a CubeSat platform.”

Foldable Antenna [12:20]

1.5U volume, Ka-band 35.75 GHz RADAR antenna.

Why Measure Weather from Space? [15:00]

These are just a few of the cubesat projects that went up on the OA9 rocket launch. To hear more about that, check out EEs Talk Tech electrical engineering podcast episode #29 – The Long Road to Space.

 

Battlebots 2018 & the Hardcore Robotics Team – #27

“I tend to not turn Tombstone on outside of the arena – it scares the crap out of me.” – Ray Billings, Hardcore Robotics team captain. We sit down with BattleBots’ resident bad boy to talk about the engineering behind the world’s meanest fighting robots. We also talk robot carnage. Because we know you’re really here for robot carnage.

“I tend to not turn Tombstone on outside of the arena. It scares the crap out of me…” – Ray Billings, Hardcore Robotics team captain. We sit down with BattleBots’ resident bad boy to talk about the engineering behind the world’s meanest fighting robots. We also talk robot carnage. Because we know you’re really here for robot carnage.

Agenda:

00:03 Ray Billings leads the Hardcore Robotics Battlebots team, and is the “resident villain” on Battlebots.

00:40 Mike went to high school with Ray’s son

01:15 Ray’s robot, “Tombstone” is ranked #1 on the Battlebots circuit. Highlights here.

1:34 The winner trophy for Battlebots is a giant nut.

2:00 Ray doesn’t turn on the robot very often outside of the arena

2:35 Ray’s carnage story: he bent a 1” thick titanium plate

3:20 You have to see combat robots live to get the full experience

4:10 The first match of Battlebots 2018 should be one of the most epic Battlebots fights of all time

4:30 Ray has done over 1,000 combat robot matches in 17 years

5:00 How Ray got into Battlebots

6:25 The main robot is called an offset horizontal spinner. It spins a 70-75 lb bar at 2500 rpm.

7:40 The body is 4130 choromoly tubing. The drive motors were intended for an electric wheelchair, and the weapons motor is from an electric golf cart.

8:20 Normal electrical motors are not designed to work for combat robots. Ray significantly stresses the motors.

8:50 The weapon motor was designed to be used at 48V 300A, but Ray uses it at 60V and 1100A (at spinup). This would overheat and destroy the motor, so it shouldn’t be done long-term.

9:40 – 70-80kW at spinup, and no start capacitor. He just uses a big marine relay.

10:00 Ray’s robot has 1 second to be lethal

10:30 If there’s a motor-stall potential mid match, Ray will turn off the motor to save batteries/electronics

11:00 What’s the weak point of Ray’s robot? One match, the weapon bar snapped in half.

11:40 Ray uses tool-grade steel, so it won’t bend, it’ll just snap.

12:40 The shock loads can break the case. The weapon motor looks like it’s rigidly mounted, but because it’s on a titanium plate it has some shock absorber. There’s also a clutch system in the sprocket to help offset shock.

13:40 Ray’s robot has to take all of the force that the opponent’s robots do (equal and opposite), but if it’s coming in a direction you want vs. one you don’t want you can design-in protection.

14:40 What test challenges were faced during assembly and design?

It’s been highly iterated. There are no shortcuts for designing combat robots. You have to see where something breaks, then adjust.

15:45 When Ray started in 2004, his robot was just a “middle of the pack” robot. With years of iteration, it’s now a class-dominant robot.

16:45 Ray spins up the robot at least once before a competition. It’ll pick up debris from the ground and throw it around.

17:50 Battery technology and batteries for combat robots: Originally they used lead acid batteries for their current ability. Now, almost everyone uses Lithium chemistry. The sport is about power-to-weight ratio, so the lighter batteries have given people much more flexibility.

19:00 Why aren’t there gas powered combat robots? There are some that have flamethrowers, and there are a couple gas powered ones. However, they aren’t as dependable.

20:15 Ray has wrecked arenas. The arena rails are 1/2” steel, and Ray can cut a soda-can sized hole in them. He’s wrecked panels and ceiling lights.

21:20 Combat robot communication systems: today everything runs on 2.4 GHz digitally encoded systems. They often use RC plane controls because they are highly customizable and there are a lot of available channels.

22:00 Drive systems: the wheels & motors come together. They use a hard foam in the tires so you can’t get a flat.

22:45 Centrifugal force – not a huge problem because the blade spins in-plane. But, when he gets bumped up the blade fights gravity before it can self-right.

24:40 The rest of the Hardcore Robotics team is three people.. The team is Ray, his son (Justin), and his friend Rick. Rick used to run his own team, but has more fun fabricating and building robots than he does driving them.

25:30 There will be 6 fights/hour, and the show will be on the Discovery channel and the science channel premiering May 11th.

26:15 The first fight got leaked in some promo footage, Tombstone vs. Minotaur.

26:35 Would Ray rather fight a good robot or a bad one? Ray says “anyone.”

Battlebots 2018 (season 3) will have “fight card” fights, then a playoff of the top 16 robots.

27:50 A given frame only lasts an event or two before needing to be replaced. This many fights is really hard on the robot.

29:20 Combat robot kits are a great way to get into the sport, especially ant-weight and beetle weight kits.

30:00 Stupid questions

31:15 Ray wants to try a new hammer robot, a full-shell spinner, and a vertical spinner.

32:40 Support Ray by getting Hardcore Robotics gear from battlebots.com and the toys from Target, Amazon, hexbugs, etc.

33:15 Ray is also an engineer at Intel.

DDR5 and 3D Silicon – #25

DDR5 marks a huge shift in thinking for traditional high-tech memory and IO engineering teams. The implications of this are just now being digested by the industry, and opening up doors for new technologies. In today’s electrical engineering podcast, Daniel Bogdanoff and Mike Hoffman sit down with Perry Keller to discuss how engineers should “get their game on” for DDR5.

“You reach critical certain thresholds that are driven by the laws of physics and material science” – Perry Keller

DDR5 marks a huge shift in thinking for traditional high-tech memory and IO engineering teams. The implications of this are just now being digested by the industry, and opening up doors for new technologies. In today’s electrical engineering podcast, Daniel Bogdanoff and Mike Hoffman sit down with Perry Keller to discuss how engineers should “get their game on” for DDR5.

 

Audio:

Sign up for the DDR5 Webcast with Perry on April 24, 2018!

Agenda:

00:20 Getting your game on with DDR5

LPDDR5 6.4 gigatransfers per second (GT/s)

“You reach critical certain thresholds that are driven by the laws of physics and material science” – Perry Keller

1:00 We’re running into the limits of what physics allows

2:00 DDR3 at 1600 – the timing budget was starting to close.

2:30  With DDR5, a whole new set of concepts need to be embraced.

3:00 DesignCon is the trade show – Mike is famous for his picture with ChipHead

4:00 Rick Eads talked about DesignCon in the PCIe electrical engineering podcast

4:40 The DDR5 paradigm shift is being slowly digested

4:50 DDR (double data rate) introduced source synchronous clocking

All the previous memories had a system clock that governed when data was transferred.

Source synchronous clocking is when the system controlling the data also controls the clock. Source synchronous clocking is also known as forward clocking.

This was the start of high speed digital design.

At 1600 Megatransfers per second (MT/s), this all started falling apart.

For DDR5, you have to go from high speed digital design concepts to concepts in high speed serial systems, like USB.

The reason is that you cant control the timing as tightly. So, you have to count on where the data eye is.

As long as the receiver can follow where that data eye is, you can capture the information reliably.

DRAM doesn’t use an embedded clock due to latency. There’s a lot of overhead, which reduces channel efficiency

9:00
DDR is single ended for data, but over time more signals become differential.

You can’t just drop High Speed Serial techniques into DDR and have it work.

The problem is, the eye is closed. The old techniques won’t work anymore.

10:45
DDR is the last remaining wide parallel communication system.

There’s a controller on one end, which is the CPU. The other end is a memory device.

11:15
With DDR5, the eye is closed. So, the receiver will play a bigger part. It’s important to understand the concepts of equalizing receivers.

You have to think about how the controller and the receiver work together.

12:20
Historically, the memory folks and IO folks have been different teams. The concepts were different. Now, those teams are merging

13:00
DDR5 is one of the last steps before people have to start grappling with communication theory. Modulation, etc.

14:10
Most PCs now will have two channels of communication that’s dozens or hundreds of bits wide.

14:45
What is 3D silicon?

If 3D silicon doesn’t come through, we’ll have to push more bits through copper.

3D silicon is nice because you can pack more into a smaller space.

3D silicon is multiple chips bonded together. Vias connect through the chips instead of traces.

The biggest delay for 3D silicon is that it turns on its head the entire value delivery system.

7 years ago, JEDEC started working on wide IO

17:15
What’s the difference between 3D silicon and having it all built right into the processor?

It’s the difference between working in two dimensions and three dimensions. If you go 3D, you can minimize footprint and connections

18:45
Flash memory, the big deal has been building multiple active layers.

19:45
The ability to stack would be useful for mobile.

21:45
Where is technology today with DDR?

DDR4 is now mainstream, and JEDEC started on DDR5 a year ago (2017)

Wide Bandgap Semiconductors for Power Electronics – Electrical Engineering Podcast #20

Wide bandgap semiconductors, like Gallium Nitride (GaN) and Silicon Carbide (SiC) are shaping the future of power electronics by boosting power efficiency and reducing physical footprint. Server farms, alternative energy sources, and electrical grids will all be affected!

Wide bandgap semiconductors, like Gallium Nitride (GaN) and Silicon Carbide (SiC) are shaping the future of power electronics by boosting power efficiency and reducing physical footprint. Server farms, alternative energy sources, and electrical grids will all be affected! Mike Hoffman and Daniel Bogdanoff sit down with Kenny Johnson to discuss in today’s electrical engineering podcast.

 

Links:

Fact Sheet: https://energy.gov/eere/articles/infographic-wide-bandgap-semiconductors

Fact Sheet
https://energy.gov/sites/prod/files/2013/12/f5/wide_bandgap_semiconductors_factsheet.pdf

Tech Assessment (Good timeline information)
https://energy.gov/sites/prod/files/2015/02/f19/QTR%20Ch8%20-%20Wide%20Bandgap%20TA%20Feb-13-2015.pdf

Agenda – Wide Bandgap Semiconductors

Use in Power Electronics

3:00 What is a wide bandgap semiconductor? GaN (Gallium Nitride) devices and SiC (Silicon Carbide) can switch on and off much faster than typical silicon power devices. Wide bandgap semiconductors also have better thermal conductivity. And, wide bandgap semiconductors have a significantly lower drain-source resistance (R-on).
For switch mode power supplies, the transistor switch time is the key source of inefficiency. So, switching faster makes things more efficient.

4:00 They will also reduce the size of power electronics.

6:30 Wide bandgap semiconductors have a very fast rise time, which can cause EMI and RFI problems. The high switching speed also means they can’t handle much parasitic inductance. So, today’s IC packaging technology isn’t ideal.

8:30 Wide bandgap semiconductors are enabling the smart grid. The smart grid essentially means that you only turning on things being used, and turning off power completely when they aren’t being used.

9:35 Wide bandgap semiconductors will probably be integrated into server farms before they are used in power grid distribution or in homes.

10:20 Google uses a lot of power. 2.3 TWh (terawatt hour)
NYT article: http://www.nytimes.com/2011/09/09/technology/google-details-and-defends-its-use-of-electricity.html

It’s estimated Google has 900,000 servers, and that accounts for maybe 1% of the world’s servers.
So, they are willing to put in the investment to work out the details of this technology.

11:50 The US Department of Energy wants people to get an advanced degree in power electronics. Countries want to have technology leadership in this area.

13:00 Wide bandgap semiconductors are also very important for wind farms and other alternative forms of energy.

Having a solid switch mode power supply means that you don’t have to have extra capacity.

USA Dept of Energy: If industrial motor systems were wide bandgap semiconductors took over, it would save a ton of energy.

14:45 A huge percentage of the world’s power is consumed by electrical pumps.

16:20 Kenny’s oldest son works for a company that goes around and shows companies how to recover energy costs.

There aren’t many tools available for measuring wide bandgap semiconductor power electronics.

19:30 Utilities and servers are the two main industries that will initially adopt wide band gap semiconductors

20:35 When will this technology get implemented in the real world? There are parts available today, but it probably won’t be viable for roughly 2-5 years.

21:00 Devices with fast switching are beneficial, but have their own set of problems. The faster a devices switches, the more EMI and RFI you have to deal with.

Spread spectrum clocking is a technique used to pass EMI compliance.

24:00 Band gaps of different materials: Diamond 5.5 eV Gallium Nitride (GaN) 3.4 eV Silicon Carbide (SiC) 3.3 eV

PAM4 and 400G – Ethernet #18

Learn how PAM4 is allowing some companies to double their data rate – and the new challenges this brings up for engineers. (electrical engineering podcast)

Today’s systems simply can’t communicate any faster. Learn how some companies are getting creative and doubling their data rates using PAM4 – and the extra challenge this technology means for engineers.

Mike Hoffman and Daniel Bogdanoff sit down with PAM4 transmitter expert Alex Bailes and PAM4 receiver expert Steve Reinhold to discuss the trends, challenges, and rewards of this technology.

 

1:00
PAM isn’t just cooking spray.

What is PAM4? PAM stands for Pulse Amplitude Modulation, and is a serial data communication technique in which more than one bit of data can be communicated per clock cycle. Instead of just a high (1) or low (0) value, a in PAM4, a voltage level can represent 00, 01, 10, or 11. NRZ is essentially just PAM2.

We are reaching the limit of NRZ communication capabilities over the current communication channels.

2:10 PAM has been around for a while, it was used in 1000BASE-T. 10GBASE-T uses PAM16, which means it has 16 different possible voltage levels per clock cycle. It acts a bit like an analog to digital converter.

2:55 Many existing PAM4 specifications have voltage swings of 600-800 mV

3:15 What does a PAM4 receiver look like?  A basic NRZ receiver just needs a comparator, but what about multiple levels?

3:40 Engineers add multiple slicers and do post-processing to clean up the data or put an ADC at the receiver and do the data analysis all at once.

PAM4 communicates 2-bits per clock cycle, 00, 01, 10, or 11.

4:25 Radio engineers have been searching for better modulation techniques for some time, but now digital people are starting to get interested.

4:40 With communications going so fast, the channel bandwidth limits the ability to transmit data.

PAM4 allows you to effectively double your data rate by doubling the amount of data per clock cycle.

5:05 What’s the downside of PAM4? The Signal to Noise Ratio (SNR) for PAM4  worse than traditional NRZ. In a perfect world, the ideal SNR would be 9.6 dB (for four levels instead of two). In reality, it’s worse, though.

5:30 Each eye may not be the same height, so that also has an effect on the total SNR.

6:05 What’s the bit error ratio (BER) of a PAM4 vs. NRZ signal if the transmission channel doesn’t change?

6:45 The channels were already challenged, even for many NRZ signals. So, it doesn’t look good for PAM4 signals. Something has to change.

7:00 PAM4 is designed to operate at a high BER. NRZ typically specified a 1E-12 or 1E-15 BER, but many PAM4 specs are targeting 1E-4 or 1E-5. It uses forward error correction (or other schemes) to get accurate data transmission.

7:50 Companies are designing more complex receivers and more robust computing power to make PAM4 work. This investment is worth it because they don’t have to significantly change their existing hardware.

8:45 PAM is being driven largely by Ethernet. The goal is to get to a 1 Tb/s data rate.

9:15 Currently 400 GbE is the next step towards the 1 Tbps Ethernet rate (terabit per second).

10:25 In Steve’s HP days, the salesmen would e-mail large pictures (1 MB) to him to try to fill up his drive.

11:10 Is there a diminishing rate of return for going to higher PAM levels?

PAM3 is used in automotive Ethernet, and 1000BASE-T uses PAM5.

Broadcom pushed the development of PAM3. The goal was to have just one pair of cables going through a vehicle instead of the 4 pairs in typical Ethernet cables.

Cars are an electrically noisy environment, so Ethernet is very popular for entertainment systems and less critical systems.

Essentially, Ethernet is replacing FlexRay. There was a technology battle for different automotive communication techniques. You wouldn’t want your ABS running on Ethernet because it’s not very robust.

14:45 In optical communication systems there is more modulation, but those systems don’t have the same noise constraints.

For digital communications, PAM8 is not possible over today’s channels because of the noise.

15:20 PAM4 is the main new scheme for digital communications

15:50 Baseband digital data transmission covers a wide frequency range. It goes from DC (all zeroes or all ones) to a frequency of the baud rate over 2 (e.g. 101010). This causes intersymbol interference (ISI) jitter that has to be corrected for – which is why we use transmitter equalization and receiver equalization.

16:55 PAM4 also requires clock recovery, and it is much harder to recover a clock when you have multiple possible signal levels.

17:35 ISI is easier to think about on an NRZ signal. If a signal has ten 0s in a row, then transitions up to ten 1s in a row,  the channel attenuation will be minimal. But, if you put a transition every bit, the attenuation will be much worse.

19:15 To reduce ISI, we use de-emphasis or pre-emphasis on the transmit side, and equalization on the receiver side. Engineers essentially boost the high frequencies at the expense of the low frequencies. It’s very similar to Dolby audio.

20:40 How do you boost only the high frequencies? There are circuits you can design that react based on the history of the bit stream. At potentially error-inducing transition bits, this circuitry drives a higher amplitude than a normal bit.

22:35 Clock recovery is a big challenge, especially for collapsed eyes. In oscilloscopes, there are special techniques to recover the eye and allow system analysis.

With different tools, you can profile an impulse response and detect whether you need to de-emphasize or modify the signal before transmission. Essentially, you can get the transfer function of your link.

23:45 For Ethernet systems, there are usually three equalization taps. Chip designers can modify the tap coefficients to tweak their systems and get the chip to operate properly. They have to design in enough compensation flexibility to make the communication system operate properly.

25:00 PAM vs. QAM? Is QAM just an RF and optical technique, or can it be used in a digital system?

25:40 Steve suspects QAM will start to be used for digital communications instead of just being used in coherent communication systems.

26:30 PAM4 is mostly applicable to the 200 GbE and 400 GbE, and something has to have to happen for us to get faster data transfer.

26:48 Many other technologies are starting to look into PAM4 – InfiniBand, Thunderbolt, and PCIe for example.

You can also read the EDN article on PAM4 here. If you’re working on PAM4, you can also check out how to prepare for PAM4 technology on this page.

 

 

 

 

Heterogeneous Computing & Quantum Engineering – #17

Learn about parallel computing, the rise of heterogeneous processing (also known as hybrid processing), and quantum engineering in today’s EEs Talk Tech electrical engineering podcast!

Learn about parallel computing, the rise of heterogeneous processing (also known as hybrid processing), and the prospect of quantum engineering as a field of study!

 

Audio link:

00:40

Parallel computing used to be a way of sharing tasks between processor cores.

When processor clock rates stopped increasing, the response of the microprocessor companies was to increase the number of cores on a chip to increase throughput.

01:44

But now, the increased use of specialized processing elements has become more popular.

A GPU is a good example of this. A GPU is very different from an x86 or ARM processor and is tuned for a different type of processing.

GPUs are very good at matrix math and vector math. Originally, they were designed to process pixels. They use a lot of floating point math because the math behind how a pixel  value is computed is very complex.

A GPU is very useful if you have a number of identical operations you have to calculate at the same time.

4:00

GPUs used to be external daughter cards, but in the last year or two the GPU manufacturers are starting to release low power parts suitable for embedded applications. They include several traditional cores and a GPU.

So, now you can build embedded systems that take advantage of machine learning algorithms that would have traditionally required too much processing power and too much thermal power.

 

4:50

This is an example of a heterogeneous processor (AMD) or hybrid processor. A heterogeneous processor contains cores of different types, and a software architect figures out which types of workloads are processed by which type of core.

Andrew Chen (professor) has predicted that this will increase in popularity because it’s become difficult to take advantage of shrinking the semiconductor feature size.

6:00

This year or next year, we will start to see heterogeneous processors (MOOR) with multiple types of cores.

Traditional processors are tuned for algorithms on integer and floating point operations where there isn’t an advantage to doing more than one thing at a time. The dependency chain is very linear.

A GPU is good at doing multiple computations at the same time so it can be useful when there aren’t tight dependency chains.

Neither processor is very good at doing real-time processing. If you have real time constraints – the latency between an ADC and the “answer” returned by the system must be short – there is a lot of computing required right now. So, a new type of digital hardware is required. Right now, ASICs and FPGAs tend to fill that gap, as we’ve discussed in the All about ASICs podcast.

9:50

Quantum cores (like we discussed in the what is quantum computing podcast) are something that we could see on processor boards at some point. Dedicated quantum computers that can exceed the performance of traditional computers will be introduced within the next 50 years, and as soon as the next 10 or 15 years.

To be a consumer product, a quantum computer would have to be a solid state device, but their existence is purely speculative at this point in time.

11:50

Quantum computing is reinventing how processing happens. And, quantum computers are going to tackle very different types of problems than conventional computers.

12:50

There is a catalog on the web of problems and algorithms that would be substantially better on a quantum on a computer than a traditional computer.

13:30

People are creating algorithms for computers that don’t even exist yet.

The Economist estimated that the total spend on quantum computing research is over 1 Billion dollars per year globally. A huge portion of that is generated by the promise of these algorithms and papers. The interest is driven by this.

Quantum computers will not completely replace typical processors.

15:00

Lee’s opinion is that the quantum computing industry is still very speculative, but the upsides are so great that neither the incumbent large computing companies nor the industrialized countries want to be left behind if it does take off.

The promise of quantum computing is beyond just the commercial industry, it’s international and inter-industry. You can find long whitepapers from all sorts of different governments laying out a quantum computing research strategy. There’s also a lot of venture capitalists investing in quantum computing.

17:40

Is this research and development public, or is there a lot of proprietary information out there? It’s a mixture, many of the startups and companies have software components that they are open sourcing and claim to have “bits of physics” working (quantum bits or qbits), but they are definitely keeping trade secrets.

19:50 Quantum communication means space lasers.

Engineering with quantum effects has promise as an industry. One can send photons with entangled states. The Chinese government has a satellite that can generate these photons and send them to base stations. If anyone reads them they can tell because the wave function collapsed too soon.

Quantum sensing promises to develop accelerometers and gyroscopes that are orders of magnitude more sensitive than what’s commercially available today.

21:35

Quantum engineering could become a new field. Much like electrical engineering was born 140 years ago, electronics was born roughly 70 years ago, computer science was born out of math and electrical engineering. It’s possible that the birth of quantum engineering will be considered to be some point in the next 5 years or last 5 years.

23:00

Lee’s favorite quantum state is the Bell state. It’s the equal probability state between 1 and 0, among other interesting properties. The Bell state encapsulates a lot of the quantum weirdness in one snippet of math.