PSRR bandwidth and supply rejection
The MAX8902AATA+T delivers 92 dB PSRR at 5 kHz, rolling off to 62 dB at 100 kHz — this defines the rejection envelope for upstream switching noise from a buck converter or charge pump. A 500 kHz switcher with fundamental ripple at 100 kHz sees 62 dB of attenuation; higher-frequency harmonics pass through with less rejection, so the output capacitor's ESL and the board layout matter for final noise floor.
Dropout and headroom budget
Maximum dropout is 120 mV at 500 mA load. The input rail must stay at least 120 mV above the programmed output voltage across the full load range — below that the output falls out of regulation. For a 3.3 V output, a 3.6 V rail gives 300 mV headroom, enough to cover dropout plus the 160 µA maximum supply current.
Protection set and soft start
Over-temperature, reverse polarity, short-circuit, and soft-start protection are integrated. The soft-start ramp limits inrush current into a discharged output capacitor, preventing the input rail from sagging during power-up. Reverse polarity protection blocks negative input voltages without an external Schottky diode.