# 8th Order Butterworth Filter with LTC1562-2 or LT1568

Hello,

I require some guidance regarding component selection for implementing a set of anti-aliasing filters.

My project requires a set of 8th order Butterworth filters with a cutoff frequency of approximately 430 kHz. I would like to ask the following:

1. I came across the LTC1562-2 but I am unsure about the phrasing in the datasheet which mentions an upper “center frequency” of 300 kHz. Is this the upper cutoff frequency? (which means that a 430 kHz cutoff frequency cannot be achieved?)
2. I also came across the LT1568, which can be used to achieve the cutoff frequency my project requires. However, the LT1568 can be used to implement 4th order filters. This might be a beginner’s question but can two such filters be cascaded to implement an 8th order Butterworth filter? If yes, could you please point me to a reference design or design source to achieve this?