TPS54160A: Whether input and output ceramic capacitors need to be placed

hi, Eevee,

what kind of test did you have to confirm  it's good to remove VinVout cap. usually we recommend to add cap close to the pin to prevent noise. like the transient test and loop stability test is helpful to determine the value. it's hard to confirm if remove the cap will not have issue in boundary condition.

may I know why you want to remove , it is layout issue

Elena

Hi, Elena

Elena Gao said:

may I know why you want to remove , it is layout issue

There have been market defects caused by C80 and C6 in mass-produced products. When we actually asked the manufacturer of the capacitor for analysis, we received a report that the part was in a broken state. Especially for C80, there have been several cases. As for the C6, not so much. We presume that the failure is caused by mechanical (external stress) rather than electrical stress. Therefore, we would like to avoid such an event by deleting the part.

Elena Gao said:

what kind of test did you have to confirm

The following is what we have confirmed.

Before and after removing the part, we checked for any difference in ripple and spike, and there was no big difference. In addition, we conducted a power supply superimposition noise test, and there were no particular problems.

Thanks,

Eevee

Hi, Elena

Elena Gao said:

and suggest to do a loop test to confirm enough phase and gain margin for loop stability,

What kind of test does "loop test" refer to? Also, what kind of state does [loop stability] refer to?

Thanks,

Eevee