• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 47 subscribers
  • Views 108 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

DAC8742H: Internal vs. External Filter, Oscillator, and Voltage Reference Performance

Matthew Henry
Prodigy 20 points
Part Number: DAC8742H

Tool/software:

I am currently using a DAC8742H as a HART modem with internal filtering, voltage reference, and oscillator. The datasheet for the DAC8742H explains that the internal filter uses less components than an external filter network. The same applies for the internal reference and oscillator.

However, what are the downsides, if any, to using the internal filter network? I have similar questions about the internal reference voltage and internal oscillator. As far as I can tell the accuracy for the internal voltage reference and oscillator should be sufficient for HART operation, so how does it compare to using external sources?

  • 0
    TI__Expert 4280 points

    Hi,

    We are reviewing this and will back to you shortly.

    Thanks,
    Lucas

  • +1
    TI__Guru* 93715 points

    Matthew,


    I don't think there's much difference between the external and internal filters in performance. There is a slightly different frequency response (based on Figures 2 through 5) but I don't think that would substantively affect the performance of the device.

    The external filter may have been implemented to allow designers to custom design filters to improve performance. However, I don't know of any designs that use a custom filter, and it seems that designs with both internal filters and the given external filters work equally well.


    Joseph Wu