TPS543320: No output

Hi Joe,

I could not see any obvious errors on the schematic. Here are my suggestions for debugging.

1. Double check all the components to make sure they are all correct. Make sure Cboot is 0.1uF with correct derating voltage. 

2. Make sure all the component connections are correctly. No cold solder or poor solder.

3. Measure BP5 pin to make sure it has 4.5V correct voltage. Make sure 12Vin is correctly applied.

4. Measure EN pin to make sure it is high.

5. Double check the layout to make sure everything is correct.

Thanks,

Nancy

Hi Nancy,

Thank you for the reply.
I have checked 1 to 5 and they seem fine.
The layout is the same for all 5x TPS543320 parts.
The output measures 0.4V
The output resistance is above 3K ohm.

Regards Joe

Hi Nancy,

Quick update.
I replaced the controller and still the same issue no output (actually +0V4)
I made some changes to isolate the load and the controller outputs +5V5.
Something is taking more current than expected when powered.
It looks like it might be going into current limit mode?
I will bench power the rail and see what current it takes.

Regards Joe

Hi Nancy,

Ok, no issue with the TPS543320 it is running with part of the load isolated.

Thank you for your help.

Regards Joe