REF3030: what is the purpose to add 5ohm resistor in series

Hello,

Depending on the capacitive load necessary for the ADC, an isolation resistor can be used to isolate the output of the voltage reference or reference buffer from the high capacitance needed for the reference pin of the ADC. A series resistor may also be used with a capacitor to ground to add a filter on the voltage reference output. 

Thanks,

Jackson