SLVU379A August 2010 – August 2021 TPS54521
The TPS54521 can track an external voltage during start up. The J5 connector is provided to allow connection to that external voltage. Ratio-metric or simultaneous tracking can be implemented using resistor divider R5 and R6. See the TPS54521 4.5-V to 17-V Input, 5-A Synchronous Step-Down Converter Data Sheet for details.