Sony V1 Integrated Processor: A deeper look

When Sony announced the WF-1000XM4 back in June, I was looking forward to seeing how Sony had improved the design and engineering in a teardown. In my main post, I did a quick teardown analysis of the device from the initial photos from Sony but this was not enough, but luckily a few days later the FCC report was finally available. The report labelled the Bluetooth IC and comparing it to Sony'press photos, it was clear the Mediatek MT2822 was the V1 chip. In that same post, I speculated that the V1 was a new chip integrating all the functions from the WF-1000M3, NC, flash memory and power management into one package. So was I close with my guess?

Before I answer that, a quick overview of the MT2822. There is very little information about the chip, The original FCC filing revealed the chip name, so we knew that a new chip was coming. The Bluetooth SIG certification revealed that the MT2822 was part of the Airoha AB156x family and support for Bluetooth 5.2. In my search for information I stumbled upon a linkedin account which mentioned the MT2822, that information is gone now, but it bundled the MT2822 with the AB1568. So if the MT2822 is a rebranded Airoha chip or a custom version for Sony is not known. Apart from that, there was no information about the chip from Sony or Mediatek/Airoha. At least Mediatek acknowledged that their chip was powering the WF-1000XM3 in a tweet.

Now thanks to an EE Times article, we have a bit of information about the new MT2822 (V1). In their teardown of the WF-1000XM4, they used a report by Techanalye which used X-ray imaging to see into the chip. The first reveal is that we are looking at 2 layers, so a stacked chip.

Source: EE Times

This photo shows the 2 different layers of the chip. According to the EE Times article, the top part is the analog layer and the lower part is the processing layer. The processing layer handles the AD/DA conversion and the analog layer is the power amplifier as seen in the last overview slide. In addition the processing layer also handles the Bluetooth 5.2 and noise-cancellation. (thanks aborne25 for the clarification).

Source: EE Times

The article says that the chip incorporates 3 different function into one, with the analog chip being the amplifier portion. The Airoba AB1568 incorporates various power management functions, noise cancellation, Bluetooth and audio processing (see here), so perhaps the MT2822 is just a custom version of the chip for Sony. So even though there is no physical QN1e in the WF-1000XM4, the guts of the chip are present in the new MT2822. It would makes sense for Sony to want to combine 3 different chips into one package in order to save on space and power. Comparing sizes, the older MT2811 was 4.8 x 4.8 mm, while the AB1568 (MT2822) is 5.0 x 5.0 mm, so not much larger but incorporating a lot more tech.

Source: EE Times

This final slide shows the various parts and how they are connected to the chip. The new Bluetooth section is much smaller and more compact now with the rest of the chip dedicated to noise cancellation and audio processing.The article also confirms that the chip was co-developed with Sony which could mean the MT2822 is just the AB1568 with Sony's own tech/algorithms integrated in, like DSEE extreme, QN1e NC algorithm, and so on (thanks aborne25).

One new piece of information from this photo is the 2 feed-forward mics for NC. Usually Sony uses one for feed-back and one for feed-forward, but it seems that both the voice mic and feed-forward mics can be used for NC. Perhaps the same scenario was present on the WF-1000XM3, but no idea how to test if that is the case. Unless the second microphone is used for wind noise suppression.

And a bonus photo, a teardown of the driver from the WF-1000XM4.

Source: EE Times

If I had 2 WF-1000XM4's, I would definitely tear one down completely, but as it stands now, still saving up for my first one. The new WF-1000XM4 sport superior tech versus the older model, but this does not mean they do not have their issues as I am reading quite a few comments online about the foam tips not lasting very long for some users.

           

If anyone is able to find anymore interesting information from the article on EE Times, please leave a comment below.

Thanks to aborne25 from twitter for the article.