Infineon Micro Avoids Philips Patent

Infineon has come out with a microcontroller which uses waves in the form of bit-streams to dim and colour-tune LEDs so avoiding Philips’ patent on a technique to dim and colour-tune LEDs using PWM waveforms.

The Infineon microcontroller uses the ARM M0 core.

As well as producing waveforms that set the colour of RGB lighting, the microcontroller can also handle transition curves between different settings and can run DALI or DMX lighting control protocols.

The 32-bit LED controllers XMC1200 and 1300 are part of Infineon's XMC1000 family



  1. There seems to be a lot of confusion about LED dimming here. PWM, PCM, PDM, even PrISM from Cypress, are all bit streams. The novelty is the type of the bit stream (PDM).

  2. NickMakesFishHappy

    SecretEuroPatentAgentMan wrote: “Using a bit stream rather than PWM seems desperate, using a 32 bit CPU to do this is hilarious. ”
    I just used their micro in a student project (aquarium lamp). It’s pretty nice and easy to use. Very similar to PWM except it’s not flickery.
    The bit stream generation is done by a dedicated module. The CPU has nothing to do with it

  3. Yes, SEPAM, I felt a bit Dante-esque wandering through an infernal Limbo to find them. I am very sorry they were not put up immediately because they are knowledgeable, insightful contributions which are much appreciated. Please let me know if any go adrift in the future.

  4. SecretEuroPatentAgentMan

    Ah, good to see you were able to recover the comments, I was beginning to wonder where they went.

  5. SEPAM While searching Limbo for the missing comment I also found another comment of yours – about the Nujira/Qualcomm patent situation. I have done the same with this as with the other comment caught by the filters and have posted it myself with your name top and bottom. Thanks and sorry again.

  6. Found it! SEPAM, the b. filters caught it. I can’t seem to get the comment to resurrect itself from limbo to publish so I’ve copied the text and pasted it into a new comment with your monicker top and bottom. No I don’t have the patent numbers. Apologies for this palaver.

  7. SecretEuroPatentAgentMan writes: Well, patent etiquette does not require an invitation before preparing for infringement analysis. And is regularity a requirement for PWM? It is simpler, yes, but I cannot see it is necessary. Both approaches can be viewed as a simple 1-bit DA converter approach wherein the technical effect is the same: to regulate the power at the LEDs. Infineon filing for a patent here is standard approach to shake loose any interesting prior art. Still since semi random bit streams are a well known equivalent gaining popularity simply to spread out the noise spectrum to get through EMC requirements I would not have high hopes for their applications. Philips will most likely go on the rampage and file third party observations or go for opposition proceedings. I agree with Anonymous that PWM dimming of colour LEDs seem rather obvious. Do you have the specific patent numbers here?
    Infineon Micro Avoids Philips Patent

  8. Sorry about that SEPAM, I will look through the entries caught by the filters. Of course if you were to register to become a trusted commenrter, which I know is a bit of a bore, then anything you post would by-pass the filters and go up instantly.

  9. SecretEuroPatentAgentMan

    Patents can be opposed and cancelled in many other ways. In this case it seems Philips was asleep at the wheel and failed to file an opposition within the time limit.
    This can be done and I do this as part of my work.
    I wrote more on a brief analysis of the situation yesterday but that seems to have been lost.


    If all the patents which should not have been granted were suddenly rescinded, the world would be a much better place in which to live. However, you should not hold your breath waiting for that to happen unless you look really good in blue (skin, that is)!

  11. wow – never knew that was patented. We were PWMing LEDs using a 6802 in 1980 :-)

  12. Yes indeed [Anonymous] I gather a lot of people think the PWM waveform patent should not have been granted to Kinetics because it was too trivial. Kinetics lasted from 1988 to 2008, so the patent could have been granted some time ago.

  13. Well, SEPAM, Infineon’s director of microcontrollers Stephan Zizala says: “The wave is in the form of a bit stream – not PWM, there is no regularity. A patent has been applied for by Infineon.” Philips’ patent derives from Kinetics which Philips acquired. Apparnetly Philips hasn’t been asked to agree it is not an infringement because Zizal says: Our assumption is we don’t violate anybody’s patent.”

  14. Hard to believe (or should I say easy to believe but hard to understand) that a patent on “a technique to dim and colour-tune LEDs using PWM waveforms” would ever be granted (unless it was a VERY long time ago)!

  15. SecretEuroPatentAgentMan

    Really? Using a bit stream rather than PWM seems desperate, using a 32 bit CPU to do this is hilarious. Time to get an analogue designer on board perhaps?
    And did Philips agree this was not infringement? I would be astonished if they did. The whole thing smells of doctrine of equivalence and a trip to a German patent court.

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