LYTSwitch-1 delayed turn-on
Posted by: Lance Johnstone
on
Hi there...
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
Lance
Hello Lance,
Thank you for using Power Integrations product. It seems there is some fault being detected leading to the turn-on delay. Do you mind sharing the schematic with the actual values/component part numbers you have used? Also, if you have some waveforms gathered, like the current or voltage of FET, it would also help if you can share them.
Thanks.