I use TPS54231 for two buck switcher designs :5V-to-1.2V and 5V-to-1.0V .There have same problems.
Below is the output. Green is 5V.Yellow is ouput.Pink is the SS pin.Blue is the PH pin.
Below is the schematic.
Step1 :I noticed the SS capacitor is too big.But the article on the forum told that is ok. I change the capacitor to 22nf. The problem remains.
Step2 :I added the 1 Meg resistor in parallel with the SS capacitor(0.1uf). The problem remains.
If the chip boots up repeatedly and frequently, It will reduce a large overshot.
I wonder if there is a reasonable explanation.
Thanks.