Day: January 17, 2023

All About USB-C: High-Speed Interfaces

January 17, 2023 by 40 Comments

One amazing thing about USB-C is its high-speed capabilities. The pinout gives you four high-speed differential pairs and a few more lower-speed pairs, which let you pump giant amounts of data through a connector smaller than a cent coin. Not all devices take advantage of this capability, and they’re not required to – USB-C is designed to be accessible for every portable device under the sun. When you have a device with high-speed needs exposed through USB-C, however, it’s glorious just how much USB-C can give you, and how well it can work.

The ability to get a high-speed interface out of USB-C is called an Alternate Mode, “altmode” for short. The three altmodes you can encounter nowadays are USB3, DisplayPort and Thunderbolt, there’s a few that have faded into obscurity like HDMI and VirtualLink, and some are up and coming like USB4. Most altmodes require digital USB-C communication, using a certain kind of messages over the PD channel. That said, not all of them do – the USB3 is the simplest one. Let’s go through what makes an altmode tick. Continue reading “All About USB-C: High-Speed Interfaces” →

The First Afghan Sports Car Has An Engine You Shouldn’t Mock

January 17, 2023 by 125 Comments

In the news today, Afghanistan has made its first sports car, and it’s a sleek and low-slung model with a throaty exhaust note that would get a second look on the Autobahn just as much as it does on the streets of Kabul. Making a modern sports car is an impressive achievement no matter where you do it, but it wouldn’t be something we’d share with you were it not for how the story is being reported. The general tone of Western reporting is focused not upon the car itself, but instead poking fun of it for using a Toyota engine also found in a Corolla.

Anyone who grew up during the Cold War will remember the rhetoric of the era with respect to technology. To paraphrase a little, our planes or rockets were based on the finest and latest high technology, we were told, while theirs were held together with string and sealing wax from the 1940s. This neglected the fairly obvious fact that Soviet probes were visiting all the planets, something they must have had some pretty good tech at their disposal to achieve. This was then explained as the product of their having stolen all our super-advanced Western tech, something we now know that our lot weren’t averse to either when the opportunity arose.

It’s this which is brought to mind by the mirth of the Western commentators at the Afghan car’s supposedly humble engine. It doesn’t matter what you think of the Afghan regime (and there’s plenty there to criticize), the car should be assessed on its merits. After all, it’s hardly as though the engine in question didn’t find its way into more than one sports car that Western commentators might find appealing.

Take A Deep Dive Into A Commodity Automotive Radar Chip

January 17, 2023 by 24 Comments

When the automobile industry really began to take off in the 1930s, radar was barely in its infancy, and there was no reason to think something that complicated would ever make its way into the typical car. Yet here we stand less than 100 years later, and radar has been perfected and streamlined so much that an entire radar set can be built on a single chip, and commodity radar modules can be sprinkled all around the average vehicle.

Looking inside these modules is always fascinating, especially when your tour guide is [Shahriar Shahramian] of The Signal Path, as it is for this deep dive into an Infineon 24-GHz automotive radar module. The interesting bit here is the BGT24LTR11 Doppler radar ASIC that Infineon uses in the module, because, well, there’s really not much else on the board. The degree of integration is astonishing here, and [Shahriar]’s walk-through of the datasheet is excellent, as always.

Things get interesting once he gets the module under the microscope and into the X-ray machine, but really interesting once the RF ASIC is uncapped, at the 15:18 mark. The die shots of the silicon germanium chip are impressively clear, and the analysis of all the main circuit blocks — voltage-controlled oscillator, power amps, mixer,  LNAs — is clear and understandable. For our money, though, the best part is the look at the VCO circuit, which appears to use a bank of fuses to tune the tank inductor and keep the radar within a tight 250-Mz bandwidth, for regulatory reasons. We’d love to know more about the process used in the factory to do that bit.

This isn’t [Shahriar]’s first foray into automotive radar, of course — he looked at a 77-GHz FMCW car radar a while back. That one was bizarrely complicated, though, so there’s something more approachable about a commodity product like this.

Continue reading “Take A Deep Dive Into A Commodity Automotive Radar Chip” →