Is it REALLY need to use some physical filter before ADC in AD9467-FMC??

Hi all,

Is it really need to use some physical filter before ADC in AD9467-FMC as i have read from AN-835 document (understanding High Speed ADC Testing and Evaluation) and UG200.

I have tested the tests which is mentioned in AD9467 data sheet and it works fine but when i go further with real signal it give some errors in 6 bits of LSB.

Cybel