Customer is testing the TPS552892EVM sweeping the input voltage with varying loads. the output is set at 15V. When the input voltage is less than 11.3V with current of about 6A, the output drops to about 12 to 13V. My first instinct was to think that the device is dissipating too much power and as a result it is limiting the output. After investigating the documentation, it seems that temperature shutdown occurs at much higher temperatures (175°C) junction and the behavior would be a complete shutdown, not a scale down. The customer measured the temperature on the package at around 70°C and also cooled down the device with forced air to the point that the case was about 50°C. There was no difference in the results. I also thought that the inductor could be losing performance at higher temperature, but we have not devised a test to prove that. Another victim could be the current sense resistor. Mind you all of these tests are on the EVM, so I am wondering what kind of comments and ideas you have about this problem. Below is a picture of the test results.
Thank you!
