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LMR33630-Q1: What is the possible cause for transient output/noise

Part Number: LMR33630-Q1

Hi team,

We got a return from customer of TI device DS90UH928QSQX/NOPB. it turn out to be a EIPD on power-supply (VDD33_B) pin's ESD block.(Max voltage:4V)

One of the possible rootcasue is some transient voltage come from VDD source. which is also TI's device "LMR33630CQRNXRQ1". Please see the below customer schematic.

Could you help to confirm below comment and advice what kind of the situation may cause transient output/noise based on schematic or device's characteristic?

1.For external possible cause,  if output element on boot circuit such as capacitor or inductor is somehow damage, it may cause the unexpected output generated to Vout. Is my understanding correct?


2.Any considerable input condition may cause unexpected output?

(For example if there is a noise happened on Vin, it may also reflect to output boost circuit to generate unexpected signal.)


3.Is it possible that noise/unstable frequency(jitter?) came from EN pin or Vin cause the unexpected output?

 If yes, could you advice what kind of condition?

4.Appreciated if you have other suggestion or let me know if you need more information.