SLVSCO4D July 2015 – February 2019 TPS65917-Q1
All SMPS outputs require an output capacitor to hold up the output voltage during a load step or changes to the input voltage. To ensure stability across the entire switching frequency range, the TPS65917-Q1 device requires an output capacitance value between 33 µF and 57 µF. To meet this requirement across temperature and DC bias voltage, using a 47-µF capacitor for each SMPS is recommended. Remember that each SMPS requires an output capacitor, not just each output rail. For example, SMPS12 is a dual-phase regulator and an output capacitor is required for the SMPS1 output and the SMPS2 output. Note, this requirement excludes any capacitance seen at the load and only refers to the capacitance seen close to the device. Additional capacitance placed near the load can be supported, but the end application or system should be evaluated for stability. See Table 6-2 for the specific part number of the recommended output capacitor.