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.

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

Power Integrity and Signal Integrity – Electrical Engineering Podcast #19

Learn about power integrity and signal integrity in this electrical engineering podcast. Power integrity will impact signal integrity, EMI, and EMC! We sit down with Kenny Johnson to discuss.

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.

How’s the impedance of your ground plane? Do you look at your power rails in the frequency domain? Mike Hoffman and Daniel Bogdanoff sit down with power integrity expert Kenny Johnson to discuss the latest trends and techniques for measuring power supplies in today’s electrical engineering podcast.

00:15 Kenny gave us a tip during scope month

01:26 There are two types of power people.

There are power producers, like the wind farms, power plants, and AC/DC adapter creators

There are power consumers, who care very much about their power quality. The ripple on power supplies, etc.

3:03 Power integrity is the study of the effectiveness of the conversion and delivery of DC power from the source to the gates on the IC.

3:45 If Moore’s Law holds out for another 600 years, we will have a computer that is capable of simulating every atom in the known universe.

4:35 Thermal hotspots were causing problems, so voltage levels started dropping

5:00 Kenny went to Amazon to look for a power integrity book. There were only 2-3 books a few years ago

Power integrity has been a thing since the 1930s

5:50 Product functional reliability is directly proportional to the power quality in a product.

We’re supplying a voltage to devices, but also current. So, this starts to look a lot like Ohm’s law.

A device has both power and a ground plane.

Power integrity pioneers include Istvan Novak and Ray Ridley and they talk about flat impedance power planes.

7:15 Flat impedance power planes – divide the supply power by the peak current, multiply it by your tolerance, you get a target impedance for your power planes.

If you can maintain a frequency flat impedance, you don’t see noise on your power supplies.

7:55 Think back to circuits 101, an inductor is open at a high frequency. And, a power plane is basically a big inductor. If you are, for example, writing high speed digital data to memory, it will be a problem.

8:40 When you look at boards, you see bypass capacitors to counteract the inductors

10:30 Experienced engineers use a lot of intuition when working out power distribution. Now, there’s a lot of localized power distribution.

11:15 A typical SSD has 12 power supplies

A tablet can have 50 power supplies

Some of our oscilloscopes have 180 power supply rails

Next generation mobile electronics 100-200 power supplies

12:25 There are redundant power supplies spread out across the device to help improve reliability. For example, there may be multiple converters that all power the same rail to help spread the loads.

The reason intuition is used is that a lot of people don’t have access to good simulation tools. They just have to use some rules of thumb and over-engineer the device to try to get reliability.

15:10 Kenny has a lot of patents. Our CTO Jay Alexander used to hold the record for most patents at the Colorado Springs site. Kenny has nearly 30 patents.

17:15 Kenny started as a probe designer, then got into power integrity.

Kenny recommends one by Bogatin about signal integrity, and a second edition called Signal Integrity and Power Integrity

18:35 SIPI labs – signal integrity and power integrity lab. Power integrity will affect your signal integrity, your EMI (electromagnetic interference) and your EMC (electromagnetic compatibility). (measure power integrity with a power rail probe)

So, the progressive companies have these SIPI labs. There are more advanced tools available.

20:10 Multiple papers say that power supply induced jitter is the single biggest source of data jitter in a digital system.

Kenny has some IOT development kits, and it’s easy to make them drop bits. Dropping bits will have an effect on battery life, performance, etc.

21:08 How to clean up a power supply? The majority of the time, it’s easiest to use a bypass capacitor. After you’ve looked at your supply in the time domain, look at it in the frequency domain. That will help you debug where the noise is coming from. And, if you know the frequency you are having trouble with, you can work backward into a bypass capacitor

22:42 There are some general rules that seem to apply to everything in electronics. Closer to the device is always better.

Next podcast – wide bandgap! The US Department of Energy will pay for some people to go back to university and get a degree in power engineering. Wide bandgap semiconductors have a huge potential to reduce energy usage.