Hi,
I am Raoyong, an analog FAE and work in Shenzhen China. I support VAPEL.
TPS2378 is used as a 18W PD controller with UC2843 in VAPEL, now they encountered an very tricky issue, the issue is as below:
When the input of PD is provided by both Ethernet cable and external adaptor, this PD can operate normally and the output voltage is stable DC voltage, but after removed the external adapter and only retained Ethernet cable, the output voltage was Pulled down to zero immediately. The customer worked hard for a week and tried to solve this issue, but they failed. Because the schedule of this project is very tight, they required TI to help them to solve this issue and explain the root cause.
Would you please tell me what is the root cause for this issue? How to solve this issue?
