I have a 33 kHz sinusoidal analog waveform with Vmin 0.5V and Vmax 2.5V. The frequency spectrum of this waveform also has minor amplitudes at frequencies higher and lower than 33 kHz that affect the phase stability of this waveform, so I want to filter these components out.
I was planning to use a Butterworth low pass filter available in Sigma Studio on ADAU1761 with the maximum available sampling rate of 96 KHz. I have used these before for signals at lower frequencies, but saw that the maximum available range on these filters is 30KHz, I cannot set any cut-off value beyond 30KHz. Could anyone explain why that is the case ?