Cirrus Logic enters Apple’s Smart Watch world

Apple Watch Series 6 teardown unveils evolutionary devices, and supply chain changes. (Headline image – Courtesy of Apple, 2020)

Courtesy of System Plus Consulting, 2020 –

Apple Inc. recently launched the Apple Watch Series 6, the latest series in its line of smartwatches, featuring a pulse oximeter for oxygen saturation measurement in the blood. Apple maintained the Watch’s sleek, square design, but this time offering a palette of new case finishes and bands.

While consumer focus is on the features, apps, and functionality, it is important to dig deep and see the high-technology components, systems, and modules that are making this new Watch Series 6 tick.

In our latest teardown report, the following are key findings from Apple’s new smartwatch:

  • Its biosensor features four sets of red, green, and infrared (IR) LEDs—the first time for any wearables—providing an extremely elaborate pulse oximeter and heart rate sensor functions.
  • Inclusion of a UWB module—the same with iPhone 11—by Universal Scientific Industrial (Shanghai) Co. Ltd (USI), that features Apple’s U1 chip.
  • Transition to Cirrus Logic for the multichannel amplifier.

The improvement of the biosensor module offers a good differentiator between Apple and anybody else. The device is quite elaborate as far as pulse oximeter and heart rate sensors go.

Meanwhile, the amplifier was previously supplied by Dialog Semiconductor, which happens to also be the supplier of power management ICs for the said watches.

While Dialog remains the main system power management IC supplier, they did lose this amplifier design to Cirrus Logic. Meanwhile, Cirrus Logic has always been supplying audio amplifiers and codecs for Apple’s iPhone and iPad products. This is the first time they made it inside the Watch.

Eliminating the force touch

Another finding by System Plus Consulting was the elimination of the Force Touch display technology.

There was a lot of effort in the last two years, not only in the watch but in a lot of products, to get this Force Touch, which is different than just touching the screen and clicking a button. Force Touch detects how hard you are pushing the screen, as opposed to just touching it. For me, they did not find enough usefulness for that extra sensory to keep it in the product.

Moreover, it was also a challenge to put Force Touch in the Watch. The system is a gasket with internal electrodes put all the way around the glass display. As you push on it, there is a tension in that gasket that was detected by an ADI chip, that then determines how hard you are pushing down on it. It is a matter of a trade-off between manufacturability and cost, versus what functionality users get out of it, when they actually use it.

Other findings available at System Plus Consulting latest teardown report

The similarities between the Apple Watch Series 6 and Series 5 devices are numerous, but with updated versions of semiconductor components, interfaces, and controllers.