Designing an Analogue to Digital Conversion CIrcuit for NI sbRIO-9651

Thread Starter


Joined Feb 10, 2012
Hi everyone.

I am looking at designing my own PCB for analogue-to-digital conversion.

The National Instruments sbRIO-9651 doesn't have ADC capabilities and so I need to create one myself.

I will be using NI MultiSIM and UltiBoard for the project.

The sbRIO has a microcontroller (NI call it an "FPGA" although it seems to function like a microcontroller to me) that can read digital inputs, so should be able to sample the analogue value and convert it to a digital value. The actual sample rate, storage etc will all be taken care of with LabVIEW programming, so the ADC circuit should just be able to take the analogue value and convert it to a digital value.

Any general advice on how to go about this will be appreciated, as well as any pitfalls, options, and also explanations on what exactly the digital output might look like.

Also, do I need to know any specific information about the sbRIO to help me with my requirements and design, or will the ADC circuit work the same regardless of the hardware I am using? I suppose knowing the digital high and low values will be all that I need to know?

Any help or advice provided will be greatly appreciated. Many thanks.


Joined Aug 21, 2008
I can't comment on National Instruments products, but I suspect there is a user group in which your problem has already been discussed.

You would be best off buying a ready-made A-to-D board. If you really want to make your own, then you would do well to use a good quality integrated circuit A-to-D converter.

You might well benefit from a classic work on the subject:The Data Conversion Handbook by Analog Devices. The last link in the list allows you to download the entire book.