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TMS320F28030: AdcOffsetSelfCal()

Ray Vincent Aranzaso
Mastermind 18180 points
Part Number: TMS320F28030


Hi,

Good Day.

During analysis of the Errata Sheet (SPRZ295Q) it became apparent, that the offset error may be greater than the specified +/-20LSB if the customer do not calibrate the device ourselves (e.g. by calling AdcOffsetSelfCal()). Can you specify a range, where the error may be if they don't do this? i.e. Is the error +/-40LSB, +/-80LSB or even +/-256, as the ADCOFFTRIM register supports this range?

Please advise. Thank you very much.

Best Regards,

Ray Vincent

  • 0
    TI__Guru* 81560 points

    Ray,

    I would say that worst case it would double the listed max/min offset for the one time calibration we have in the DS table(below).  That spec is +/-20LSBs for one time cal.  If a customer is relying on the Device_Cal() function then it could be +/-40LSB over the full use case of the device. 

    That is it might be at the +20LSB(worst case) at nominal conditions and then drift over temp an additional +20LSB to +40LSB.

    In any case the offset error should be fully correctable with the ADCOFFTRIM register over the operational range of the device.

    Best,

    Matthew

  • 0 in reply to MatthewPate
    TI__Genius 12760 points

    Matthew, Ray,

    thank you for your swift support.

    This answers my customers question. His end customer has now to decide if the the error is okay or if he wishes to implement AdcOffsetSelfCal().

    BTW: I recommended the newer F28003x with better specs if he is able to change the device.

    If further action is needed I will care about that.

    Regards,

    Bernd