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I have a problem with this circuit on a PCB I just made. The output is designed at 3.3 V. But, I have a reading of 6 V on the output and a reading of 1.1 V on the FB pin (0.6 normally). This is with a 2 K resistor as load. The output voltage seems really stable, but weirdly increases a little when the load has lower resistance.

Is the IC dead? What other steps could do to diagnose the problem?

What references can I use to solve these kind of problems?

Schematic

Layout

Whole board

Buck Output

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Mattias Vinet Larouche is a new contributor to this site. Take care in asking for clarification, commenting, and answering. Check out our Code of Conduct.
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  • \$\begingroup\$ What do you mean by "when the charge has lower resistance"? \$\endgroup\$ Commented Nov 16 at 18:02
  • \$\begingroup\$ I put a 400 resistance instead and Vout went up to 7V. \$\endgroup\$ Commented Nov 16 at 18:05
  • \$\begingroup\$ Your positioning of the SW node vias is subpar, but shouldn't be a problem. Also, what is the inductor's part number? \$\endgroup\$ Commented Nov 16 at 18:06
  • \$\begingroup\$ Can you explain what you mean by "the charge"? Do you mean the load? ("Charge" means something completely different; this might be a translation issue.) \$\endgroup\$ Commented Nov 16 at 18:07
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    \$\begingroup\$ Mostly just check if the waveforms look as expected; that would help narrow down the cause of the problem. Might also be worth it to verify that component values are what you expect, and you don't have a completely wrong capacitor or something. Verify that the IC is actually a TPS54202, too; I've gotten the wrong part in a bag labelled as the right part before, from reputable distributors--it just happens sometimes. \$\endgroup\$ Commented Nov 16 at 18:27

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