TPS54541: TPS54541 Current Limit

Hello HYY

This part should easily deliver 5 A with the right external components. If you are looking for less current, there is a 3-A variant. The current limit cannot be adjusted. I notice that both the inductor and the diode are not rated for the current that you are looking for. In the case of the diode, the primary problem would be temperature. This diode may also cause excessive noise. In the case of the inductor, it may saturate. Assuming that the 47 uF output capacitors are ceramic, stability should be OK.
In order to debug your circuit try:

1) Use a huge (high current but still 8.6 uH) inductor. Since it is already inductive, you may connect it with short wires.
2) Try putting 3 of your diodes in parallel.
3) Noise can also be caused by layout so compare your layout to this part’s EVM layout.
4) Finally, check to make sure that the part is not becoming very hot. If there is no thermal path away from the part in your layout, the part may be over heating.

Regards, Robert