Difference Between the Analog Anti-Aliasing Filter and the IIR Filter

Updated Aug 22, 2023

Reported In


  • PXIe-4303
  • PXIe-1071

Issue Details

I have a PXIe-4303 and I see that there are two filter options, an anti-aliasing filter and an IIR filter. What are the differences between these?


The anti-aliasing filter is a lowpass filter meant to attenuate signals above the Nyquist frequency to prevent aliased signals. The 4303 automatically sets this based on the sampling rate. It uses a combination of analog and digital filters to achieve this, as documented in the User Manual

The IIR filter is a user configurable digital AI filter that can be added to an input in addition to the anti-aliasing tracking filter. It can be useful to add in environments where there is excessive high frequency noise that is below the anti-aliasing filter threshold.