Google Pixel 10 PWM dimming upgrades could hurt your eyes less — if you go Pro

Since the launch of the Pixel 9 series, Google has been revising its Pixel strategy. Instead of the Pro Pixels being larger, slightly better versions of the base Pixels as they had been in previous years, the Pro tier became a whole different class of phones. This year, that trend continues, with all evidence suggesting the baseline Pixel 10 will be closer to the A series Pixels than the Pro models.

It appears that Google will lean into this growing divide even further with its display tech, as we’ve learned that the Pixel 10 is considering a display with a higher PWM frequency — but only on the Pro models.

DC vs PWM dimming explained

Before we get to the main part of the article, a bit of background about display dimming, as it’s a complex topic. There are two main ways to do it — DC (voltage) and PWM (pulse width modulation). The two approaches have fundamental differences, which I’ve illustrated in the diagrams below (check here to see the Matlab script that created this illustration).

DC dimming simply lowers the voltage that’s connected to the display to lower its brightness. This has its advantages — it’s a very simple concept, generally provides decent results on LCDs and doesn’t have any “side effects” on the human perception of displays it’s used in. Unfortunately, that’s where the advantages end. The circuitry for DC dimming is more complex and pretty inefficient. Another problem is that it’s hard to create a circuit that will be able to provide a wide range of voltage to enable dimming the display down to very low levels. It also doesn’t work super well with OLEDs; due to the complicated chemistry involved, lowering voltage not only decreases the brightness, but also affects the color response in a fairly unpredictable way.

That’s where PWM steps in. Instead of lowering the voltage, it leaves it at the rated value, but only turns the panel on for a selected percentage of the time. Obviously, this wouldn’t work really well if, say, we turned the display on and off every half second, so it needs to happen really fast. At just a few hundred hertz (or times per second), this switching becomes nearly invisible to the human eye. Unfortunately, this comes with a caveat — some people are sensitive to this, and will get headaches from using displays that are dimmed like this, unless they are run at a very high frequency. Other than this, however, PWM dimming only has advantages — the color reproduction is impacted to a way smaller degree, it’s very easy to get really dim, and it’s a more efficient technology.

What is changing with the Pixel 10 series?

Google Pixels have utilized PWM dimming for a while, but unfortunately, Google left the PWM frequency fairly low. The Pixel 9 Pro only refreshed at around 240Hz. Following the launch of the Pixel 9a, Google was asked about the lack of updates to help fix the flicker concerns, and it hinted to Android Central that it would provide some progress with the Pixel 10. Thankfully, that appears to be coming true — but only if you’re planning to shell out for the Pro or Pro XL.

The new phones are expected to run at 480Hz PWM refresh rate — at least in some conditions, as they may also support 240Hz. This isn’t great, but it’s still an improvement, which would track with Google’s recent stance on the matter. As a comparison, some phones support a whopping 4320Hz PWM, a nine-fold advantage over Google’s phones. I’ve compiled a table comparing the Pixel 10 Pro range’s potential upgrade to some of its competitors below:

Other than that, the Pixel 10 series is only expected to enjoy minor display upgrades. The sizes and resolutions appear to be staying the same, while the declared (HDR) peak brightness should be getting bumped up around 200 nits across the board. This, however, isn’t really an issue as the displays are already excellent after the Pixel 9 series massively upgraded them across the board.

While it’s good to see Google finally taking steps to address such a critical issue, it’s disappointing that it could lock that solution to its most expensive phones. Hopefully, this will be amended for future generations. Whatever the case, we’ll know for sure when the Google Pixel 10 series finally arrives, with an official launch expected sometime in August.