Hi,
I'm using a TPS55340PWP as step-up to convert 24VDC voltage to a 25.8V to 36V output.
The output voltage is set by a potentiometer to define the level needed on the load.
It works pretty well during approximately 10h, but suddently, during the middle of a test, the TPS55340 has burn. In fact, the SW pin (both pin 1 & 2) are short-circuited to the ground (measured after unsoldering it with a multimeter).
During the test, the output voltage was set to 32V, with approximately 2A on the Load.
Before that, I've monitor the temperature of the IC (with thermal camera) many times and the TPS55340 wasn't hot at all (not more than 50°C). The only component quite hot was the Diode (approx 70°C).
Does anyone ever experiment this kind of problem?
We will mount a new IC and redo the test, but I'm afraid that will happend again. This converter is supposed to be protected against short circuit, thermal and has a built-in current limitation, so I didn't understand how it can burn.
here's my schematics, all value were selected using webench simulation:
Thank you