The TPS74901 is designed to operate from an input voltage from 1.1V to 5.5V, provided the bias rail is at least 1.75V higher than the input supply. The bias rail and the input supply must both provide adequate headroom and current for the device to operate normally.

Connect a low-output impedance power supply directly to the IN pin of the TPS74901. This supply must have at least 1µF of capacitance near the IN pin for stability. A supply with similar requirements must also be connected directly to the bias rail with a separate 1µF or larger capacitor.

If the IN pin is tied to the bias pin, a minimum 4.7µF of capacitance is needed for stability.

To increase the overall PSRR of the solution at higher frequencies, use a PI-filter or ferrite bead before the input capacitor.