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?

 

 

 

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

How Internet is Delivered – Data Centers and Infrastructure – #12

Laser Netflix delivery, backyard data centers, and how the internet gets delivered to homes and businesses. This week’s podcast guest is optical guru Stefan Loeffler. 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.

Laser-delivered Netflix and backyard data centers!

The conversation continues with optical communications guru, Stefan Loeffler. In this episode, Daniel Bogdanoff and Mike Hoffman discuss optical infrastructure today and what the future holds for optics.

Video version (YouTube):

 

Audio Version:

Discussion Overview:

Optical Communication Infrastructure 00:30

Optics = Laser-driven Netflix delivery system

Client-side vs line-side 1:00

Line-side is the network that transports the signals from the supplier to the consumer

Client-side is the equipment that is either a consumer or business, accepting the data from the network provider.

 

Yellow cables in your wall indicate presence of fiber 1:40

Technically, optics is communication using radiation! But it is invisible to us as humans. 2:20

 

Getting fiber all the way to the antenna is one of the major new technologies 2:30

But this requires you to have power at the antenna 2:45

However, typically there is a “hotel” or  base station at the bottom of the antenna where the power is and where fiber traditionally connects, instead of up to the antenna

Really new or experimental antennas have fiber running all the way up the pole  3:28

 

Network topologies- star, ring, and mesh 3:42

Base stations are usually organized in star-form, or a star network pattern. A star network starts at a single base station and distributes data to multiple cells

Rings (ring networks) are popular in metro infrastructure because you can encircle an entire area 4:20

Optical rings are like traffic circles for data.

Is ring topology the most efficient or flexible? 6:20

An advantage of ring and mesh topologies is built-in resilience

Mesh topologies have more bandwidth but require more fiber optic cable 7:10

How often is the topology or format of a network defined by geography or regulations? 8:30

 

How consumers get fiber 9:20

Business or academic campuses typically utilize mesh networks on the client side, subscribing to a fiber provider

Fiber itself or a certain bandwidth using that fiber can be leased

If you’re a business, like a financial institution, and latency or bandwidth is critical, leasing fiber is necessary so you have control over the network 9:45

 

What’s the limiting factor of optical? 

What are the limitations of the hardware that’s sending/receiving optical signals? 11:08

Whatever we do in fiber, at some point, it is electrical 11:27

There will be a tipping point where quantum computing and photon-computing (optical computing) comes into play 11:40

Will optical links ever compete with silicon? Maybe we will have optical computers in the future 12:02

The limiting factor is the power supply 12:40

What’s costing all this energy? 12:58

The more data (bits and bytes) we push through, the more energy in the form of optical photons or electrons we are pushing through. We also must use a DSP for decoding which costs energy

One of the first 100 Gb links between two clients was between the New York Stock Exchange and the London Stock Exchange 14:00

 

The evolution of the transmission of data 14:45 

Will we ever have open-air optical communication? 15:50

RF technology uses open-air communication today, but it is easy to disturb

The basic material fiber is made of is cheap (silica, quartz), and can be found on any beach 16:08

Whereas copper has a supply problem and, thus, continues to increase in price

 

Other uses for optical 16:33

Crystal fiber and multicore fiber is being experimented with to increase the usable bandwidth

Optical, as waveguides, can be built into small wafer sections 17:15

Optics is used in electrical chips when photons are easier to push through than electrons

Cross-talk can happen with optical, too 18:13

Testing is done with optical probing, which works because of optical coupling

Optical-to-electrical converter solution 

 

Optical satellite communication 19:48

Hollow-fiber could be used in a vacuum, such as space

The refractive index of the fiber’s core is higher than the cladding, which guides the optical signal through 21:05

A hollow-fiber would be like a mini mirror tube

 

Optical data transmission 21:25 

Higher carrier frequencies means you can modulate faster, but there’s more loss and dispersion

This means optical communication could be harder in open-air vs. in traditional fiber 22:45

70-80% headroom is typical

The congested part of a network drives the change in technology. 24:25

 

Mega data centers vs. distributed data centers 

Cooling and power is important so big data centers are being built by Google, Facebook, Netflix in places where cheap, cool water is abundant 24:30

Distributed data centers are becoming more popular than mega-data centers 24:55

All images on Facebook have “cdn” in the URL because the image is hosted on a content distribution network, or cloud

Data centers are described by megawatts (MW) of power, not size or amount of data processed 26:20

Internal data center traffic takes up about 75% of the traffic 27:47

Distributed networks utilize a mesh network and require communication between networks

 

Telecom starts using faster fiber when about 20% of the fiber is used 28:55

This 20% utilization is also common in CAN busses because of safety-critical data communication

Uptime guarantees require the Telecom industry to keep this number at 20%

 

Keysight optical resources and solutions  31:00

Predictions 31:45

Also, check out our previous conversations with Stefan about Optical Communication 101 and Optical Communication Techniques.

Optical 101 – #9

How does optical communication work? We sit down with Stefan Loeffler to discuss the basics of optics and its uses for electrical engineering.

Optical communication 101 – learn about the basics of optics! Daniel Bogdanoff and Mike Hoffman interview Stefan Loeffler.

Video Version (YouTube):

Audio version:

Discussion overview:

Similarities between optical and electrical

Stefan was at OFC
What is optics? 1:21
What is optical communication? 1:30
There’s a sender and a receiver (optical telecommunication)
Usually we use a 9 um fiber optic cable, but sometimes we use lasers and air as a medium

The transmitter is typically a laser
LEDs don’t work for optical

Optical fiber alignment is challenging, and is often accomplished using robotics

How is optical different from electrical engineering?

Photodiodes act receivers, use a transimpedance amplifier. It is essentially “electrical in, electrical out” with optical in the middle.

Optical used to be binary, but now it’s QAM 64

Why do we have optical communication?
A need for long distance communication led to the use of optical.
Communication lines used to follow train tracks, and there were huts every 80 km. So, signals could be regenerated every 80 km.

In the 1990s, a new optical amplifier was introduced.

Optical amplifier test solutions

Signal reamplifcation vs. signal regeneration

There’s a .1 dB per km loss in modern fiber optic cable 11:20
This enables undersea fiber optic communication, which has to be very reliable

How does undersea communication get implemented?
Usually by consortium: I-ME-WE SEA-ME-WE

AT&T was originally a network provider

What is dark fiber (also known as dark fibre)?
Fiber is cheap, installation and right-of-way is expensive

What happens if fiber breaks?

Dark fiber can be used as a sensor by observing the change in its refractive index

Water in fiber optic line is bad, anchors often break fiber optic cable 17:30

Fiber optic cable can be made out of a lot of different things

Undersea fiber has to have some extra slack in the cable
Submarines are often used to inspect fiber optic cable

You can find breaks in the line using OTDR – “Optical time domain reflectometry”

A “distributed reflection” means a mostly linear loss. The slope of the reflection tells you the loss rate.

The refractive index in fiber optic cable is about 1.5

Latency and delay 23:00
The main issue is the data processing, not the data transmission

A lot of optical engineers started in RF engineering 24:00

Environmental factors influence the channel, these include temperature, pressure, and physical bends
Recently thunderstorms were found to have an effect on the fiber channel

Distributed fiber sensing is used drilling

Polarization in fiber, polarization multiplexing techniques
Currently, we’re using 194 THz, which gives 50 nm windows

Future challenges for optical 28:25
It’s cost driven. Laying fiber is expensive. And, when all dark fiber is being used, you have to increase bandwidth on existing fiber.

Shannon relation 30:00

Predictions 31:10

Watch the previous episode here!