Unused outputs should not be left unconnected. If an output left unconnected is accidentally enabled, inductor current dumps into an open pin, and the output voltage can soar above the absolute maximum rating, potentially causing damage to the device. If the unused output is always disabled (EN_SBBx = 0x4 or 0x5), connect that output to ground. If the unused output can be enabled at any point during operation, please refer to "Unused Outputs" section on page 68 of the datasheet (Rev 6 7/18) for detailed suggestions on circuit connections.