editor's blog
Subscribe Now

Rezence Wireless Charging Takes Steps

There have been a couple of developments in the wireless power world over the last couple months, both involving the new Rezence standard. You may recall that this is the new high-frequency resonant approach, as contrasted with the established lower-frequency Qi approach. We’ve reviewed the differences and proliferating standards before.

While Rezence beat out Qi in terms of establishing a resonant (as opposed to inductive, which is what legacy Qi is) standard, Qi (a resonant version of which is in the works) benefits from established infrastructure and channels. And standards aren’t product. So the Rezence allies have been trying to spin up infrastructure and design enablement so that they can get products on the market. Only then can they say that their approach has been truly proven and validated.

Late last year, they took another step in that direction. WiTricity released a development kit, the WiT-5000C3, to make it easier for designers to leverage the Rezence standard. The kit contains:

  • A full-on reference design for a Class 3 charger (up to 2 smartphones or 1 tablet);
  • Sample PTUs (power transfer units, aka chargers) and PRUs (power receive units, or chargees);
  • Engineering eval tools; and
  • A full set of documents.

WiT-5000C3_system.png

 (Image courtesy WiTricity)

One thing I noticed in the release was a reference to “classes” and “categories.” As in, this design is for a Class 3 charger, compatible with Category 3 devices and with tablets.

I inquired further into what this meant, and WiTricity sent the following tables. You can tell the standards folks had a task of choosing similar but different words for PTUs and PRUs. PTUs come in “classes”; PRUs come in “categories.” There’s no rule linking a particular class number to a category number – not in terms of what mates with what, nor in terms of power level.

Tables.png

As a Class 3 charger, then, it should be able to charge, at a minimum, one Category 4 device (tablet or phablet) and must support the maximum number of devices, two Category 3 units (smartphones). Just so happens that, from a power standpoint, 2x(Category 3) = Category 4…

Meanwhile, the expected merger between the Alliance for Wireless Power (A4WP) and the Power Matters Alliance (PMA) organizations was announced: a letter of intent has been signed, and the deal should complete mid-year.

While this was touted as proving that a “standards war” isn’t necessary, it also represents a blending of two relatively similar approaches. There’s a much bigger gap between the remaining two organizations. And, as far as I can tell, there’s little chance of further diplomacy. Both remaining sides – high- and low-frequency charging – remain firmly committed to their approaches.

You can find out more in the WiTricity dev kit announcementand the merger announcement.

Leave a Reply

featured blogs
Jan 21, 2022
Here are a few teasers for what you'll find in this week's round-up of CFD news and notes. How AI can be trained to identify more objects than are in its learning dataset. Will GPUs really... [[ Click on the title to access the full blog on the Cadence Community si...
Jan 20, 2022
High performance computing continues to expand & evolve; our team shares their 2022 HPC predictions including new HPC applications and processor architectures. The post The Future of High-Performance Computing (HPC): Key Predictions for 2022 appeared first on From Silico...
Jan 20, 2022
As Josh Wardle famously said about his creation: "It's not trying to do anything shady with your data or your eyeballs ... It's just a game that's fun.'...

featured video

Synopsys & Samtec: Successful 112G PAM-4 System Interoperability

Sponsored by Synopsys

This Supercomputing Conference demo shows a seamless interoperability between Synopsys' DesignWare 112G Ethernet PHY IP and Samtec's NovaRay IO and cable assembly. The demo shows excellent performance, BER at 1e-08 and total insertion loss of 37dB. Synopsys and Samtec are enabling the industry with a complete 112G PAM-4 system, which is essential for high-performance computing.

Click here for more information about DesignWare Ethernet IP Solutions

Featured Paper

EV Kit for ADI’s nanoPower 300nA Quiescent Current, Synchronous Step-up DC-DC Module

Sponsored by Analog Devices

Learn how to use the MAXM17225 EV kit with detailed procedure and circuit connections to test the MAXM17225’s functionality. Some of the features of the ev kit include a 0.4V to 5.5V input range, a 1.8V to 5V resistor selectable output voltage, and 1A peak inductor current limit.

Find Out More

featured chalk talk

Just 1-Wire to Power and Operate I2C or SPI Endpoints

Sponsored by Mouser Electronics and Analog Devices

If you are working on a connection or IO constrained design, a one wire solution could be a great way for you to power and operate your I2C or SPI endpoints. In this episode of Chalk Talk, Amelia Dalton chats with Scott Jones from Maxim Integrated about the DS28E18 communications bridge: a one wire solution that can help you address a variety of system level challenges including protocol conversion, wiring limitations, and communication distance concerns.

Click here for more information about the Maxim Integrated DS28E18EVKIT Evaluation System