TPS50601A-SP: What happens when external SYNC is lost on an TPS50601A-SP?

Hi,

There are two answers to this question on E2E:

• "TPS50601-SP: Synchronization Timeout", and
• "TPS50601-SP External Sync Mode"

Both of these answers are for the TPS50601-SP, not the TPS50601A-SP, but I assume they still apply. However, they are contradictory: the first one says

The only caveat here is that after the oscillator is disabled and if for whatever reason the external clock is no longer provided, the device will not go back to using the internal oscillator.

and the second one says:

The SYNC pin will constantly be looking for a toggling signal. If SYNC is high for more than 20 us, then the TPS50601-SP will transition to its internal clock until SYNC starts toggling again.

Can you let me know which is the correct answer? This determines whether a failsafe external oscillator is necessary or not.

thanks,
Graeme