editor's blog
Subscribe Now

New Intersil RGB Sensor

Intersil has announced a new RGB sensor, and they’ve laid out some of the things that it’s good for. But let’s back up a sec before diving in.

RGB sensors sound pretty straightforward, and their utility seems pretty obvious. But they’re not the only light sensors in town, so first let’s position them with respect to other light sensors on that system that everyone wants a piece of: the smartphone.

There’s already an RGB sensor on your phone: it’s in the camera. It’s on the back of the phone, typically. On the front side, there are two other light sensors. There’s the ambient light sensor (ALS), which simply detects light intensity so that it can decide how much to dim the screen (and other things like lighting a keyboard). The main difference between an ALS and an RGB sensor is that the RGB sensor provides three channels of data for the three colors; the ALS just gives one number. And the ALS typically costs less, although Intersil sees cost parity on the horizon.

The other light sensor on the phone is the proximity sensor; it combines an IR LED with an IR detector to figure out whether you’re holding the phone to your cheek so that it can disable screen functionality. While Intersil’s new sensor actually can detect down into the near infrared range, it can’t function as the detector in the proximity sensor, so we won’t travel down that path any further.

If you subscribe to cost parity between ALS and RGB sensors, then having and RGB sensor handle the ALS function can help with the various kinds of glass now being used on phones. Colored glass in particular can complicate detection, so a tunable RGB setup can help deal with that. Sensitivity is important here, since the glass on most phones can block up to 90% of the light.

Light intensity is measured in “lux” units; full daylight is 100K luxes; moonlight is 1 lux. But if you only get 10% of the light, then full daylight will look like 10K lux behind the glass. So they focused on sensitivity up to that range, going down to 0.005 lux at the bottom end for dark environment performance.

So that’s phones, but there are other ideas afloat as well. Color calibration of screens to printers is one. More interesting, since it’s a dynamic application, is compensation for display aging. In particular, with OLEDs, the blue color component is newer and less “perfected,” so it ages more quickly than the others. That means that the color mix changes over time.

Using an RGB sensor, that change can be detected and compensated by boosting blue power to keep consistent color over the life of the screen. They can sync with multiple sensors for the case where the display is divided into regions, each with its own sensor. The same can be done for projectors (minus the regional thing).

Meanwhile, LEDs are bringing some fundamental changes to room lighting. In the past, there were a couple discrete choices for light “temperature” (a measure of the “whiteness” color): incandescent and fluorescent. But LEDs can be tuned to some extent, and individual LEDs also vary, so identical arrays of LEDs might have different temperatures.

For all of these cases, an RGB sensor can help detect the temperature and maintain consistency both unit-to-unit and over time. You could even change the lighting color to suit your mood.

In a camera, a sensor can detect the ambient light temperature and compensate the exposure accordingly. In fact, by having a separate sensor do that, the exposure can be pre-computed, significantly reducing some of the lag time between button-push and picture-take.

From a spec standpoint, Intersil says they’re differentiated by three characteristics: size, accuracy, and – of course – power.

They claim the smallest device, with a 1.65×1.65-mm2 package. Their accuracy (“total error” on the data sheet) is 10%, as compared to 15% and higher with other parts.

Power is specified at less than 1.45 µA quiescent, 85 µA active. Those are the max numbers; other numbers floating around reflect typical numbers (and they have measured against their competition to establish who has lowest typical power as well – they say they have the data to prove that they do).

You can find more in their announcement.

Leave a Reply

featured blogs
Apr 9, 2021
You probably already know what ISO 26262 is. If you don't, then you can find out in several previous posts: "The Safest Train Is One that Never Leaves the Station" History of ISO 26262... [[ Click on the title to access the full blog on the Cadence Community s...
Apr 8, 2021
We all know the widespread havoc that Covid-19 wreaked in 2020. While the electronics industry in general, and connectors in particular, took an initial hit, the industry rebounded in the second half of 2020 and is rolling into 2021. Travel came to an almost stand-still in 20...
Apr 7, 2021
We explore how EDA tools enable hyper-convergent IC designs, supporting the PPA and yield targets required by advanced 3DICs and SoCs used in AI and HPC. The post Why Hyper-Convergent Chip Designs Call for a New Approach to Circuit Simulation appeared first on From Silicon T...
Apr 5, 2021
Back in November 2019, just a few short months before we all began an enforced… The post Collaboration and innovation thrive on diversity appeared first on Design with Calibre....

featured video

Meeting Cloud Data Bandwidth Requirements with HPC IP

Sponsored by Synopsys

As people continue to work remotely, demands on cloud data centers have never been higher. Chip designers for high-performance computing (HPC) SoCs are looking to new and innovative IP to meet their bandwidth, capacity, and security needs.

Click here for more information

featured paper

Understanding the Foundations of Quiescent Current in Linear Power Systems

Sponsored by Texas Instruments

Minimizing power consumption is an important design consideration, especially in battery-powered systems that utilize linear regulators or low-dropout regulators (LDOs). Read this new whitepaper to learn the fundamentals of IQ in linear-power systems, how to predict behavior in dropout conditions, and maintain minimal disturbance during the load transient response.

Click here to download the whitepaper

Featured Chalk Talk

Cloud Computing for Electronic Design (Are We There Yet?)

Sponsored by Cadence Design Systems

When your project is at crunch time, a shortage of server capacity can bring your schedule to a crawl. But, the rest of the year, having a bunch of extra servers sitting around idle can be extremely expensive. Cloud-based EDA lets you have exactly the compute resources you need, when you need them. In this episode of Chalk Talk, Amelia Dalton chats with Craig Johnson of Cadence Design Systems about Cadence’s cloud-based EDA solutions.

More information about the Cadence Cloud Portfolio