SNOS412O February 2000 – June 2020 LM1117
The adjust terminal can be bypassed to ground with a bypass capacitor (CADJ) to improve ripple rejection. This bypass capacitor prevents ripple from being amplified as the output voltage is increased. At any ripple frequency, the impedance of the CADJ should be less than R1 to prevent the ripple from being amplified:
The R1 is the resistor between the output and the adjust pin. Its value is normally in the range of 100-200Ω. For example, with R1 = 124Ω and fRIPPLE = 120Hz, the CADJ should be > 11µF.