Analog signal acquisition

[Soumya_MIT]

Does NI have any ADC that can acquire analog signals up to 30 MHz?

[Kyle97330]

Without any more information other than just "30 MHz" it's hard to know for sure.  How many channels at once, what sample length, what sample resolution, what voltage levels, budget, etc.

There are these that almost certainly can do it, but are quite expensive with a very small volt range:

https://www.ni.com/en-us/shop/hardware/products/flexrio-digitizer-device.html

Would a NI oscilloscope work?

https://www.ni.com/en-us/shop/hardware/products/pxi-oscilloscope.html

https://www.ni.com/en-us/shop/hardware/products/oscilloscope-device.html

[Soumya_MIT]

Hi Kyle,

Thank you for your quick response.

I need one/two channels. 10 to 12-bit with few millivolts. 

Actually, I will acquire data from a photodiode which is coupled to a laser interferometer. I need to downconvert the photodiode signal (filter out carrier high-frequency signal) and do a few numerical analyses such as differentiation, subtraction, and integration using LabVIEW software. 

I want to do the signal acquisition using DAQ assistance and signal processing in LabView in real-time. I don't want to spend more than 1-2k on ADC. Could you please if any NI DAQ is available that will support my requirement? 

[santo_13]

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@Soumya_MIT wrote:

Hi Kyle,

Thank you for your quick response.

I need one/two channels. 10 to 12-bit with few millivolts. 

Actually, I will acquire data from a photodiode which is coupled to a laser interferometer. I need to downconvert the photodiode signal (filter out carrier high-frequency signal) and do a few numerical analyses such as differentiation, subtraction, and integration using LabVIEW software. 

I want to do the signal acquisition using DAQ assistance and signal processing in LabView in real-time. I don't want to spend more than 1-2k on ADC. Could you please if any NI DAQ is available that will support my requirement? 

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You want a DAQ with at least 60MHz sampling rate (30MHz signal frequency) at $1-2k? you might as well ask for a new Lamborghini for $10k.

You are looking for a mainstream DAQ with 10-12bit resolution in the mV range with 60MHz + sampling rate.

You can get some cheap Chinese oscilloscopes for that price-point, but don't expect a instrument grade accuracy that too with 10-12-bit resolution.

[Kyle97330]

By any chance are you a student or grad student?

If you just need this for a single project, maybe look into local places that rent out test equipment instead of buying it.  That's probably the only shot at getting the performance you want at the price you mention.

If this is corporate then you simply need to ask for a higher budget.

[Soumya_MIT]

Thank you so much for the information, Kyle.

I am a student. I need this for a single project.

I will definitely reach out to nearby labs that have such systems.

I am also trying to interface an oscilloscope with LabView. Let me see if that works for me.

Have a nice day!

[santo_13]

Typical scopes are 8-bit and ENOB will be even lower, the accuracy specs are pretty mediocre for any scope as they are not meant to be precise measurement devices.

[Soumya_MIT]

Hi Santo,

Thank you so much for your response.

I am trying to interface a Tektronix TPS2014 with LabVIEW.

There are some USB oscilloscopes available that can be interfaced with LabVIEW: https://digilent.com/shop/analog-discovery-2-100ms-s-usb-oscilloscope-logic-analyzer-and-variable-po... 

Will it be helpful?

Could you please suggest any third part ADC available in the market that can be interfaced with LabView and cater to my requirement?

Thank you for spending some of your good time helping me!

[santo_13]

Analog Discovery 2 is a good option, just to ensure you understand, this is a hobby grade piece of equipment with absolutely no guarantee on the accuracy and un-calibrated.

If you don't need a proper NIST traceable calibrated measurement with proper specifications, Analog Discovery 2 would be a cheap solution.

[Soumya_MIT]

Thank you so much for your response, Santo!

Actually, I am new to this type of analog data acquisition using DAQs.

Could you please refer to some literature where I can read about the difference between calibrated and un-calibrated data acquisition?