in the datasheet version-A page 29 is reported that for calculation of data rate with the SINC3_MAP option active, the output data rate can be calculated using the equation ODR=fmod/(32*FILTCON). It is expressely specified that to obtain 50 SPS a value of 5000 is needed, in fact the formula of fmodulator @ 8Mhz / 32 / 5000 = 50. To my experiment the result is to be = to 8Mhz / 32 / 3 / 1666 to obtain 50 SPS.
Do you confirm?
I assume this factor of to have 3 relation with the settling time that would divide the data rate by 3 (top of the SINC3 filter paragraph).
There is a different explanation?