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SM320F28335-EP: SM320F28335-EP ADC error calibration

V Naresh Kumar Reddy
Prodigy 30 points

Part Number: SM320F28335-EP

If SM320F28335-EP is used, then

1. How can we improve ADC performance using internal software. Can the errors be reduced using software?

2. What could be the calibration process ?

3. If calibration is done using internal references, How much performance can be increased?

4. If external references are used, how the errors will be impacted? After calibration what could be the expected error ? Can you please provide the data for error reduction after calibration using Boot-ROM , external reference and internal reference.

  • 0
    TI__Guru* 85620 points

    Thanks for reaching out to the C2000 E2E forum.

    I'll clarify the different aspects of ADC calibration and references below:

    1)ADC Calibration inside the TI OTP that is done as part of the device init:

    This is required to be ran to achieve the ADC specifications listed in the F28335 datasheet for both gain and offset error(as well as overall ADC goodness). This function call is in all of our C examples and part of the device_init function.

    2)This device had an internal BG reference that will meet the DS specs listed for it.  There is also an option of supplying an external reference voltage on the ADCREFIN pin.  This has the potential advantage of a better temperature coefficient than the internal reference, but that will be based on its characteristics

    3)Additional/external based calibration:  This can be done to reduce the temperature change in the gain/offset of the ADC.  I would recommend looking at this application note on ADC calibration .  While this mentions the F2808 device, it also applies to the SM320F28335-EP device.

    Let me know if this clears things up.

    Best,

    Matthew