Other Parts Discussed in Thread: PMP40514,
Hi,
We have made a design using TPS23756. The design was made with the help of the following documents: SLVU329A, SLVA305C, PMP40514, PMP6659, SLVA306A. So the final design is a bit of a mix of everything. We use option 2, adapter preference and APD for ORing but we currently only test with PoE, without an external adapter attached.
The issue is that immediately upon connecting the ethernet cable, the circuit exhibits a clicking noise, the TPS23756 is starting to heat up and no output is generated. If left connected for long enough, the IC overheats and is destroyed.
We did manage to get an output on one of the prototypes but was not particularly stable. Also it worked depending on where you touched the circuit (sometimes). The audible clicking noise also changed in amplitude and frequency. We weren't able to determine the source of the noise as the design is very compact.
For testing we currently use a 48V PoE injector (Farnell order code 2854400) with a 220 ohm load (12 V output).
Is there a way to share the schematic and BoM privately?
Best regards, Jure