TPS650941EVM-116: About self turn on

Hi Sakai-san,

Can you provide an oscilloscope image describing what you are observing?

At a high level, the FET should not be at risk of self turn-on because the PMIC will be driving the gate of the FET to 0V.

The TPS65094 device will turn on if the PMICEN pin is high, and if the THERMTRIPB signal is not also high, the PMIC will shut down after reaching S5 state. Then, if PMICEN is still high, it will power on again. This cycling effect is often mistake as an unexpected DC voltage (i.e. a 1.8 V rail will measure as 1.2 V because it is on until S5, then off again, then back on again in a cycle).

Last item is that CSD87381P is going to be very marginal for 15 A max. The CSD87588N on BUCK2 should be able to support 15A, but I would not necessarily expect CSD87381P to be able to handle 16.5 W output. The device may be having a power fault / current limit event causing shutdown.

Hi Kevin-san,

As it is the waveform of our customer, I would like to discuss it by e-mail or direct message of E2E community.
Is it possible?

Best regards,
Yuto Sakai