TPS7A8300 PSRR an Output Noise in case of adjustable operation

Reiner,

The noise and PSRR will be the same if the resistors used for the adjustable version are the same sizing (i.e. R1 = 12.10 kOhms, R2 near Anyout resistor values). The high frequency noise may go down if the resistors are smaller than the Anyout resistors, or increase if the feedback resistors are larger due thermal noise. The PSRR should be unaffected by the sizing of the resistors, unless you cause excessive loading on the FB pin by using very small resistors, or the leakage into the FB pin is near the same magnitude as the current through R2. General rule of thumb is that the resistors should be 1kOhm to 1MegOhm, and keeping their sizing near the AnyOut sizing is advised (6kOhm to 200kOhm).

The following application note explains more on this mechanism:

http://www.ti.com/lit/an/slyt201/slyt201.pdf

Regards,

David