Can you quantify 'very quick'?
Rather than try filtering, is it feasible to remove the noise from source? A filter will introduce delays
If noise is picked up along the signal path, you could amplify the source and increase the signal to noise ratio.
Given a quantified sample rate, would your FPGA be able to oversample and average?
Have you looked at the vi.lib filtering VIs?
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- Cheers, Ed