The LD56100DPU18R: Power-supply rejection ratio is specified at 70 dB at 1 kHz, rolling off to 55 dB at 100 kHz. This means upstream switching noise from a buck converter at 1–2 MHz is attenuated by roughly 55 dB — enough to keep ripple below 1 mVpp on a 1.8V digital core rail, provided the input capacitor is placed close enough to avoid parasitic inductance nulling the rejection at high frequency. Maximum dropout voltage is 285 mV at the full 1A load. Protection features include over-current, over-temperature, and short-circuit shutdown — the regulator folds back or latches off rather than exceeding its safe operating area, which simplifies fault handling in a distributed power architecture.
8-XFDFN package — board-fit checklist
The 8-XFDFN exposed-pad package (1.6 x 1.2 mm body) is a surface-mount DFN with a thermal pad on the underside. The supplier device package designation is 8-DFN (1.6x1.2), and the package / case is 8-XFDFN Exposed Pad — this is a standard footprint for 1A LDOs in this form factor.