TPS57040 Buck converter wont work

[eem2am]

Hi,
I am doing a 30Vout, 0.435Aout Buck, with von = 38V.
It uses TPS57040.
None of the 10 prototypes have worked. One of the boards did work, but regulated to 26.5Vout instead of the 30V that the divider was setting it to...strangely, this board wouldnt work at all when i changed the compensation resistor from 133k to 10k (the compensation C , in series with it. was 10nF).

I am not using any ESD precautions as there are none available. The floor i am standing on is linoleum.

TPS57040
https://www.ti.com/lit/ds/symlink/t...08316&ref_url=https%3A%2F%2Fwww.google.com%2F

 

[bertus]

Hello

Did you follow the recommendations for the pcb design?
There should be thermal vias under the chip.
The bottom of the chip should also be connected to ground

Bertus