TPS54678 is the recommended alternative device to TPS54680. Please refer to the TPS54678EVM for new device evaluation.
The TPS54680EVM Evaluation Module allows the designer to evaluate the TPS54680 for use in a multiple voltage sequencing scheme. The TPS54680 tracking regulator is paired with a TPS54610 to demonstrate simultaneous power up and down of the two voltages. However, any DC/DC converter can be used to provide the master voltage signal and multiple TPS54x80's can be used in the application to sequence more than two voltages.
Please see the TPS54680EVM User's Guide (SLVU077) document for more information.