TIDA-00349: Supply shutdown problem

Akshay Patel said:

shutdown

Awaiting revert

Hello Akshay,

sorry for the delay in our response and please allow us until beginning of next week to analyze your issue.

Thanks and regards

Alex

Hi Akshay,

for your problem is not so easy to find a starting point to investigate further. You have tested the MCP16311 stand alone and it is working and can only be stopped by shorting it. 

Also the circuit works when removing the isolation with the TPS60402, right?

Is something in the complete circuit heating up? How much current is the whole circuit drawing from V_in?

How does the load at MCP1703, so on the ISO_3.3V rail look like, is this a pure resistive load? Can it happen that this load draws way too much from the rail? What happens if this rails gets shorted? Does a short on this rail also trigger the MCP16311 to stop working?

In a second step I would recommend to check the current going into the circuit with the TPS60402, maybe remove R11, soldering a short piece of wire and measuring with a current clamp and a scope what is going on there. Do you see a current peak higher then the normal operation current here when the circuit stops working?

Best regards,

Steffen