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ADS1231: ADS1231

chethan kumar
Prodigy 20 points
Part Number: ADS1231

Hi Team,

I need some explanation or justifiction for selecting the Analog input filter circuit for above ADS1231REF board schematic.

Please can you explain on what basis film capacitors are used(100pF) and 100uF is used for VREF Pin.

  • 0
    TI__Mastermind 24940 points

    Hello, I have edited this response. 

    This device was designed to be used with bridge sensor inputs. Can you share how this device is being used, and the signal source?

    A Basic Guide to Bridge Measurements this is a comprehensive document about bridge sensor inputs 

    As for the capacitors, the surface mount film caps are PPS (Polyphenylene Sulfide) caps with no polarity.  They are a film cap that is relatively small compared to other film caps and much lower noise than multi-layer ceramic. because bridge applications need a low noise level (2nV ADC resolution) as possible the PPS caps were likely  used instead of ceramic for the input filter caps and the CAP pins.  Ceramic can be used if higher noise is acceptable.

     C44 and C45 are EMI filter caps similar to X2Y in construction.

     The 100uF tantalum used for C4 is used to reduce reference noise when the analog supply is used as the reference.  This is only necessary if the measurement is non-ratiometric.

    Regards

    Cynthia