Hi!
I have a weird behaviour of the schematic for 12-24 to5V buck regulator based on TPS5430.
The schematic was desifgned in WEBENCH & the components were chosen according to the recommended BoM. I've cross-checked the WEBENCH calculations with the formulas from the datasheet and they seem to be correct.
However, what I see is that the circuit wouldn't start. The PH pin oscillates and the output voltage is fixed to 1.225V. What is also weird, the Vsense voltage is the same 1.225V.
I've tried replacing the TPS5430 with another one - obviously no luck. I've also tried playing with input/output capacitance - no changes. I'm attaching the relevant parts of schematic & layout as well as an oscilloscope trace from PH pin.
Any advice/ideas?