SNVA962 December 2020 TPSM5601R5H
When configured in an IBB topology, the voltage across the device is equal to the input voltage minus the output voltage (where the output voltage is a negative value). One must make sure to keep the voltage across the device less than the specified maximum input voltage (VIN_MAX) of the device. The maximum input voltage in an IBB configuration can be calculated by using Equation 5.
where
As a result, in an IBB configuration the input voltage range is reduced. For example, the TPSM5601R5H has an input voltage range of 4.2 V to 60 V. Therefore, for a desired output voltage of –5 V, the input voltage now has an operating range of 4.2 V to 55 V.