Tool/software:
We are using TPS63710 to convert 8-12 V input to -5.3 V output. Out of 48 PCBs assembled, 7 have had the same issue of TPS63710 not starting.
This is the schematic:
The inductor L1 is Bourns SRN4026-4R7M. There is no load connected, the output voltage goes to a connector.
During a faulty startup, the input voltage does not drop low enough to trigger the voltage supervisor, which is here:
On the malfunctioning units the output voltage looks like this:
It is possible to fix the malfunctioning units by replacing the L1 inductor with a new but identical part. This suggests that the circuit may be sensitive to variations in a certain inductor parameter.
I request your support for debugging.
