Silicon Labs Shrinks Wireless SoCs to Extend BLE to Miniature Devices | Hacker News Reader

Silicon Labs Shrinks Wireless SoCs to Extend BLE to Miniature Devices

allaboutcircuits.com

73 pointsWaitWaitWha24 comments

The antenna is the limiting factor IIRC, the smallest module available is this thing: https://www.fdk.com/cyber-e/electronic_components/module/ble... which has the antenna as a slot in the package itself.

Limiting factor for what application?

The battery/power supply alone is going to be at least an order of magnitude larger in volume.

"The battery/power supply alone is going to be at least an order of magnitude larger in volume."

Indeed, people do use rechargeable lithium batteries like the 50mAh CR322 (22mm by 3mm) or smaller CR311, but these would only be able to handle a 11mA EFR32BG29 output load for a few hours at most... Yet in a mostly dormant power save mode YMMV =3

if we're talking about a device that only needs centimeters worth of range and spends most of its time in deep sleep, those 50mA could last quite a while.

And would last a whole lot longer if the BLE manufacturers would pull their heads out of their asses and give us a chip with RTC wakeup current that doesn't suck.

Microcrystal can make these things to run at <50nA. https://www.microcrystal.com/en/products/real-time-clock-rtc...

All the BLE manufacturers are 1uA plus. It's infuriating.

The BG22 consumes 0.5 uA in EM4 mode with the BURTC+LFXO enabled.

You wouldn't use a chip antenna if you're that tight on PCB space.

A trace at the circumference of the PCB, or a wire antenna that only take up space for the solder joint would do.

Fractal antenna!

https://en.wikipedia.org/wiki/Fractal_antenna

With the right pcb design you could use this to sneak in an entire microcontroller while making it seem like it's just an antenna, wild

This one is ever so slightly smaller at 3.25 x 8.55 x 0.85mm: https://www.mouser.com/ProductDetail/TAIYO-YUDEN/EYSHSNZWZ?q...

Six of them fit on the face of a dime, which is wild.

Unlike the FDK module, this module requires an external crystal oscillator, which makes me think that the total footprint ends up being larger.

To be fair to Silicon Labs, they don't claim the smallest BLE module but FDK did exactly that [1].

[1] The world's smallest Bluetooth® Low Energy Module, the new model "HY0021":

https://www.fdk.com/whatsnew-e/release20241021-e.html

The Hongjia HJ-131 is much smaller at 4x4x1.3mm https://www.renesas.com/en/document/dst/da14531-honjia-hj-13...

This doesn't integrate the antenna, so it's not comparable.

Yes it does. The HJ-131 module has an onboard antenna that’s used by connecting pins 12 and 13.

This doesn't have MTP flash or anything though which is a bummer.

It's bit silly to say that they shrink SoC when the new chip is exactly the same package as their previous generation from few years ago.

Is this not just a worse version of the nRF52 and nRF54 lineup? Larger size, fewer hardware peripherals, lower radio sensitivity. What is the new thing for this chip?

Compared to nRF52840(same ram/flash/packaging), this is nearly a millimeter smaller x/y, 3dB better sensitivity, 2.5x faster ADC sample rate(but who knows what that means with a +8dBm radio firing near it), and hopefully not botched readout protection. No USB though, big deal for some.

I'm not familiar enough with the nRF54 series, but it's good to have a few competitors in this space.

The nRF54L15 looks better in most aspects. I mention the nRF52840 as it is a veteran in the space with a rich ecosystem at 1mm larger.

Nordic Semiconductors has BLE SOCs in even smaller packages. E.g. the nRF54L15 is available in a 2.4 x 2.2 mm package.

I don't immediately see a picture of the actual chip to get a reference size bybitself, that that chip inside the tooth is pretty wild. I wonder how you would even begin to power electronics within such a space. Or perhaps this is more of a marketing level of graphics.

From the article:

> The BG29 chips will be available in 5 mm × 5 mm QFN and 2.6 mm × 2.8 mm WLCSP form factors

That "wireless oral health monitor" example is a concept from Lura Health[1] that integrates a marginally smaller BG27 (2.3mm x 2.6mm WLCSP)[2].

[1] https://lurahealth.com

[2] https://www.silabs.com/applications/case-studies/small-bluet...

The second link isn't exactly forthcoming on the battery technology used, but at least says:

> and its power consumption is low enough that the device can last from six months to a year on a battery of the equivalent size

The average "width" of the first mandibular molar from this article[1] is 5.1-5.2mm. It sure would be interesting to see a CAD model of the design inside the module on the band. The graphics from the posted article vs. the first link above are also a bit different, making it even harder to infer much I think.

[1] https://pmc.ncbi.nlm.nih.gov/articles/PMC5502574/

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