PXI-5922 internal 24bit ADC chip

[andreasosso]

Anyone knows what AD converter chip is used inside the PXI-5922A?

[santo_13]

Are you using the part number of ADC used in the instrument?

If you have one, you can take apart the heat sink to find out.

[andreasosso]

Thanks Santosh, I'm not the owner of the instrument and found no info about that in the tech docs. I'm trying to do a detailed analysis of the performances, beyond data summarized in 5922 specs.

[santo_13]

Unfortunately, as you would use the instrument as a whole and not take it apart, any specifications beyond it are not available.

Why would you need the ADC part number, are you going to desolder it from the board and use it? without any of the front end and other supporting circuits?

[andreasosso]

Dear Santosh,

I need detailed information about the device for scientific purposes, namely application to quantum voltage standards for primary metrology. Specs provided by NI are very succinct in many points, as one can see looking at data sheets form ADCs manufacturers. That's why knowing the chip would help fill the info "gaps". Didn't know it was such a carefully kept secret. 🙄

Thanks, anyway

[santo_13]

You can raise a support request with your query and details of why you may need that info, maybe you get what you're looking for.

[Henrik_Volkers]

I know the colleages from PTB use this card with JAWS ... maybe they know more? 

Also some more infos about the internal FIR filter would be nice, but it seems that NI can't provide that info any more, even if they are willing to do so 😞 

My guess: Maybe NI hired a group of smart people who designed it, made a nice product, but after all this years these people (and the detailed knowledge) is no longer (easy) available.

NI had some presentations about the the 5922 (at the time it came out) and maybe you can find some patents .. 

I don't think it's a IC made by one of the big ones (TI, AD, ...)

[andreasosso]

Thanks Henrik for your reply.

Sure I know our colleagues working with JAWS, yet the analysis of digitizer internals is generally very limited in papers about Josephson standards.

In the meantime I've found an appnote from NI explaining in more detail how the PXI-5922 digitizer operates and, yes, it turns out that they didn't use a commercial chip, but custom designed a new one. If you're interested in the topic, some relevant patents are also cited in there.

In case you're willing to further discuss the subject, please fell free to contact me at my INRiM email address.

Tschüss

Andrea

[YHJIANG]

Hello, I would like to ask you if you have an answer to this question? I also have a problem like this that needs to be solved（PXI-5162 internal 10bit ADC chip）.

[andreasosso]

Hi Yhjiang,

still some interest in more detailed specs on NI hardware: a noticeable fact. Unfortunately, I cannot provide info for your specific case. As you can read, after Googling and searching through NI docs, I found some relevant info on the 5922. I suggest to try the same. Looks like we're such a few to ask NI, anyway