I recently came across an Analog Dialogue article "Why Does Voltage Reference Noise Matter?".
It perfectly described one of the problems I encountered while trying to get the best performance out of the 24b ADC I am using.
The following question refers to the online version of this article:
Sadly, contacting the author Mr Shah directly is not possible, because he recently left ADI and is now working fo another company.
This is the reason I am asking in the forum.
In the test circuit description, it says there is one 10uF Wima capacitor.
I assume the capacitor Mr Shah is referring to here is C7? (Please correct me if I am wrong)
According to the test circuit description, all other capacitors are MLCCs.
My question is:
What kind of capacitors are used in the reference filter?
They seem to be too large in value to have a type 1 ceramic as the dielectric.
While using type 2 ceramics in my capacitors, I had severe problems with vibrations being picked up by my filter due to the microphonic behaviour of type 2 ceramics.
I tried using aluminium electrolytics and tantalum capacitors, but their (temperature-dependent) leakage and dielectric absorption messed up the DC-accuracy of the reference.
Furthermore, dampening or getting rid of slight vibrations is not possible in this use case.
I have not yet tried MLCCs with flexible terminations, but before continuing to search for a solution to my problem, I wanted to ask you about some further information about the type of capacitors used in the article.
It would be a great help, if you could give me some further information on the topic.
Thank you very much in advance.