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OPT3101: Expected amplitude after illumination xtalk calib and calib parameters using external temp sensor

Moses Christian
Prodigy 170 points
Part Number: OPT3101

I have following questions:

1. Expected amplitude after illumination xtalk calibration (with Rx or Tx covered)

In document sbau310, P.7, 4.2.3, says that expected crosstalk amplitude is below 200 codes with highest LED current.
But in document slau791, P.14, 4.2.1, says that the expected amplitude is below 10 codes.

Which one should I follow?
What should I do if I can't make the amplitude below 10 codes?

2. Calibration parameters using external temp sensor

Is the main purpose of external temp sensor only to calibrate phase offset and cannot calibrate illumination xtalk?

According to what I understand, the supported function of internal/external temp calibration is as following list:

Internal temp External temp
Illumination xtalk supported not supported
Phase offset supported supported

What if I set both internal/external temp calibration parameters?
Is there a register that can control which calibration parameter to use?

Is there any better to use external temp for calibration than internal one?

I'm working on calibration of our new design.
I was planning to start collecting data in thermocamber this week but something gone wrong.
So I hope I can resolve the question above asap. Thanks in advance.

  • 0
    TI__Intellectual 1070 points

    Hello,

    1) Difference is that the crosstalk of <200 codes is pre-calibration and <10 codes is post calibration.  You should be able to reach <10 codes with calibration.

    2) Both an internal and external temp sensor can be used for both illumination crosstalk and phase offset.  With an external temp sensor, you can achieve better resolution but we recommend that you test both and choose whichever gives the best performance.  We have see good results with both.

    Rahland

  • 0 in reply to Rahland Gordon
    Prodigy 170 points

    Thanks for reply!

    Answer no.1 is understood.

    About answer no.2, how can I set the register to let it use internal temp or external temp for calibration?

    Why there is no clue about using external temp for illumination xtalk calibration in document sbau310?

  • 0 in reply to Moses Christian
    TI__Expert 5035 points

    Hi Moses, 

    Thank you for your patience, we're working through a lot of demand right now. We'll have a response for you within 48 hours. 

    Kind regards,
    Nick Z

  • 0 in reply to Moses Christian
    TI__Intellectual 1070 points

    Hello Moses,

    The registers for temp are listed in Table 9 and Table 10 of the sbau310 document.  For measuring external temp reading, the device must be configured to read from the TILLUM device register.

    For xtalk calibration, this is discussed in section 4.2.4 of the same document and an external temp sensor can also be used.

    More information can also be found in the document Accurate Measurements with OPT3101

    Rahland