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REF6141: Better than REF3140 + OPA350?

Part Number: REF6141
Other Parts Discussed in Thread: DDC316, REF3140, , OPA350, REF35

Good afternoon,

In one of my designs I am using a DDC316. In the reference schematic in the datasheet of the DDC316 (p.19 Figure 15), an external reference is supplied by a REF3140 and a OPA350. Due to limited space on my design, I would like to use the REF6141 (which has an integrated buffer) instead. However I am struggling a bit with determining if this is a good option regarding noise and stability, since the DDC316 has a 16-bit resolution. Looking at the numbers and calculations, I would say that the REF6141 is the better option to use with the DDC316. Is this correct?

If not; would there be a noticeable difference in performance if I were to use the REF3140 with the DDC316 internal buffer instead of the external OPA350?

Kind regards,


Ramon Jansen

  • Hi Ramon,

    When selecting a voltage reference, there are a few things to consider. You are correct that the REF6141 would have better noise and stability than the REF3140. However, if you decide to use the internal buffer of the DDC316, then a voltage reference such as the REF34, REF35, or REF50 could be sufficient solutions that don't have their own integrated buffer depending on your noise, long term drift, and temperature drift specifications.

    When selecting an external buffer or the internal buffer, you can look at the electrical characteristics listed on page 4 of the DDC316 datasheet to help you make that determination. There seem to be variations in current and power consumption depending on which one you use.  

    If supply current and power consumption are not a major concern in your design, I would recommend using the internal buffer of the DDC316 along with one of the voltage references I suggested above. Otherwise, the REF6141 is a good option.

    Thanks,

    Jackson 

  • Hi Jackson,

    Thank you for your quick and clear reply. Using the internal reference buffer might be a good consideration as well then, since power consumption is not an issue. I was a bit hesistant to use it since there is barely any specification about it in the datasheet. Though on the other hand, it may be expected to be good enough as to not impact functionality of the DDC316 itself.

    Kind regards,

    Ramon Jansen