Consider the following application situations when choosing the output capacitors.

After an output short occurs, the TPS254900A-Q1 device abruptly reduces the OUT current, and the energy stored in the output power-bus inductance causes voltage undershoot and potentially reverse voltage as it discharges.

Applications with large output inductance (such as from a cable) benefit from the use of a high-value output capacitor to control the voltage undershoot.

For USB port applications, because the V_BUS pin is exposed to IEC61000-4-2 level-4 ESD, use a low-ESR capacitance to protect OUT.

The TPS254900A-Q1 device is capable of handling up to 18-V battery voltage. When V_BUS is shorted to the battery, the LCR tank circuit formed can induce ringing. The peak voltage seen on the OUT pin depends on the short-circuit cable length. The parasitic inductance and resistance varies with length, causing the damping factor and peak voltage to differ. Longer cables with larger resistance reduce the peak current and peak voltage. Consider high-voltage derating for the ceramic capacitor, because the peak voltage can be higher than twice the battery voltage.

Based on the three situations described, a 10-µF, 35-V, X7R, 1210 low-ESR ceramic capacitor placed close to OUT is recommended. If the battery voltage is 16 V and a 16-V transient voltage suppressor (TVS) is used, then the capacitor voltage can be reduced to 25 V. Considering temperature variation, placing an additional 35-V aluminum electrolytic capacitor can lower the peak voltage and make the system more robust.