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ADS8317: Non-volatile memory

Seishin
Genius 4135 points
Part Number: ADS8317

Hi,

I have a customer using ADS8317 in their products.
Waveform jumps when output code is near zero.

ADS8317 Data Sheet P.16 THEORY OF OPERATION
I found the following description.

Differential linearity for the ADS8317 is factory-adjusted via a package-level trim procedure.
The state of the trim elements is stored in non-volatile memory and is continuously updated
after each acquisition cycle, just prior to the start of the successive approximation operation.

■Question
Is there a possibility that the adjustment value of the internal non-volatile memory is erased
or changed?
For example, is it caused by the following?
・Logical sequence
・Logical interface
・Power　 sequence
・Signal　level

Best regards,
Seishin

  • 0
    TI__Mastermind 49445 points

    Hi Seishin,

    Could you please share the complete ADS8317 schematic, including the front end driver amplifier and RC filter, reference driver circuit, supply circuitry connections including the bypass capacitors?

    The reason I ask for the schematic is that the device is a SAR ADC, where the internal sample-and-hold capacitor needs to be driven to the target voltage within the acquisition period. The driver amplifier and RC filter must be carefully design and have enough bandwidth and/or low output impedance to completely re-charge and settle during the acquisition period. The inputs on a SAR ADC are are not high-impedance and there is an amount of charge kickback expected as the S/H (sample-and-hold) switches.  It is possible that the device is going through a significant code transition at this voltage level, and therefore charge kickback occurs.  If the driving amplifier does not have enough bandwidth to recharge and settle the sample-and-hold, this could potentially show as the behavior shown above.

    Thank you and Best Regards,

    Luis Chioye

    SAR ADC Applications

  • 0 in reply to Luis Chioye
    Genius 4135 points

    Dear Luis,

    Thank you for your response.

    I have attached the ADS8317 schematic.

    ADS8317_circuit_diagram.pdf

    Best regards,
    Seishin

  • 0 in reply to Seishin
    TI__Mastermind 49445 points
    Hi Seishin,

    I will be contacting you directly via email.

    Thank you,

    Kind Regards,
    Luis
  • 0 in reply to Luis Chioye
    Genius 4135 points
    Hello Luis,

    I have just sent you an email.Could you please check it.

    Best regards,
    Seishin
  • 0 in reply to Seishin
    TI__Mastermind 49445 points

    Hi Seichin,

    Yes, this communication/query is being addressed directly via email

    Thank you and Best Regards,
    Luis