LYTSwitch-1 delayed turn-on
I'm using a LYT1604 in a low-side buck 20W 60V integrated LED PCB driver. Some of the units are experiencing a turn-on delay of between 1 to 5 seconds. Once they start they run at the correct power level.
The circuit is as per Fig.1b in LYTSwitch-1 datasheet. Values used for the various components are as per recommendations from PIXIs 10. I have tried replacing the LYT1604, but the problem persists. The circuit seems to perform the same on both working and non-working boards - power on BP pin ramps up uniformly to VCC in ~7ms, etc. but FET switching is delayed on the 'faulty' units.
Can you please shed some light on what might be the cause?
Thank you, regards