TPS54360 synchronization

[void_error]

This chip was chosen for one of my projects mostly because of availability and space constraints and it's going to be synchronized to an external clock provided by the microcontroller it's going to power which means that it has to start up without a sync signal present.

The datasheet gives two examples for external sync so there's two ways it can be done.

Since I'm going to have two regulators based on this IC on the same board and I want to have both of them sync'd I thought it might be a good idea to provide one of them with an inverted signal, because, well, is that better for the bulk filter cap after the rectifier?

In case I stick to out of phase sync signals how should I approach this? Use 3-state buffers?

[void_error]

Forget about this, even though most of the circuit takes less space compared to the LTC3824 I wanted to use initially there still wouldn't be enough board space left for the sync circuitry.
Swapped the TPS54360 out for a LT3680 which has a dedicated sync pin. Still sticking with the differential sync to the two regulators, got a +5V and a +12V rail.

The challenge will still be to clock the sync pin only if there's a sync signal present.

[prasimix]

If I understood you correctly you have two SMPS regulators. Do you want to sync them with external sync signal or just want to promote one of them to master and sync the other (slave) with inverted sync signal?

[void_error]

I want to sync both to an external signal coming from a microcontroller on another board which is going to be powered by this board through a local regulator, also sync'd.
One of the two LT3680s will receive an inverted sync signal.