Complete noob asking simple questions. In LM1084 datasheet there is mention of bypassing adjust pin to gnd with a capacitor to increase ripple rejection. That only is possible on adjustable version. I need 5V and there is a fixed 5V version but would that perform worse than adjustable one at 5V with bypass cap on adjust pin?
Looking at the NatSemi datasheet from 2005, the 5V version has 68dB (typical) of ripple rejection. On page 7, it describes the adjustable version as having 75dB, though that is degraded as Vout/Vref becomes greater. At 5V it is -12dB, dropping the ripple rejection to 63dB. That, though, can be compensated with a bypass capacitor, so the adjustable version ends up with the better ripple rejection numbers.