SYNC_FAULT with TPS546D24A

[skot]

There appears to be an undocumented silicon-level issue with the TPS546D24A variant voltage regulator in a multi-phase setup that results in a SYNC_FAULT shutdown after ~20 minutes of use. The issue does not occur with an otherwise identical PSU, PCB, firmware config but with the newer TPS546D24S fitted. TPS546D24S based BitaxeGT builds have run without fault for weeks.

I have not been able to find any combination of TPS546D24 register config register settings that solves this issue with the TPS546D24A. Texas Instruments support suggested that this might be a noise issue on the VSHARE, SYNC and/or BCX signals connecting the two phases. Being as this issue does not occur on an identical build with the TPS546D24S (and the noise is not significant anyways) this points to a specific issue with the TPS546D24A.