Hello TI team,
I am Trong, our Hardware Team got a problem with Power Supply using TPS54360 Reference Design.
We designed more than 10 PCBs using the same Power Supply Circuit as above. Some of them work well while others do not.
Phenomenon: There are strong oscillations when Heavy Load starts to be connected (below picture), which affect all circuits using +5V power line.
After testing, I figured out this problem caused by SW pin and COMP pin of TPS54360.
1. Testing with PCB that has TPS54360 work well:
Channel 1 (Yellow): Voltage Clamp at COMP pin.
Channel 2 (Pink): Switching waveform at SW pin.
- Light Load:
- Heavy Load:
2. Testing with PCB that has problem with TPS54360:
Channel 1 (Yellow): Voltage Clamp at COMP pin.
Channel 2 (Pink): Switching waveform at SW pin.
There is no change at COMP Voltage and SW waveform when I turn on the Heavy Load. I guess that TPS54360 is kept at Pulse Skipping Eco-mode.
I tried to remove TPS54360 and re-solder a brand new part TPS54360, changed C88 from 33pF to 39pF (exactly as Reference Design), but I still received the same issue.
Please kindly help me troubleshoot this issue.