TPS65094: failure during start up

Hi,

I have assigned your request to responsible Applications Engineer and we will get back to you as soon as possible.

Regards,

Murthy

Hi,

Can you try reading the OFFONSRC, PWR_FAULT_STATUS1, and PWR_FAULT_STATUS2 registers? This is the best way to determine what is causing your issue.

Hi,

Any updates on this issue?

Hi Nick

sorry for late.

Please refer to below.

Thanks,

Bruce

Bruce,

Are you sure this was taken after the failure occurred? It looks like the PMIC is off based on the PG_STATUS registers, and hasn't reported a shutdown.

Hi Nick

The system will auto reset repeatedly and I also found the " RSMRSTB " will become low.

More waveforms for your reference.

Thanks

Bruce

Hi Nick

Thanks for your feedback.

I tried to pull high thermal_trip signal by +V1.8A , but the system is still reset.

Any idea can explain the issue is causing by processor not PMIC

Here is my method that how to pull high.

setp1 Remove R184

Step2 Add a wire from +V1.8A

Step3  Connect to PMIC pin60 directly.

Thanks,

Bruce

Bruce,

Unfortunately it is hard to say what is causing the shutdown if we aren't reading anything from the PMIC. You could try doing that again, or you can try probing PCH_PWROK. If that goes high at any point, then you know the power up sequence is completing successfully. Then you can probe each of the rails, SLP signal, and PWR_EN to see if there is anything strange on any of those signals at the same time PCH_PWROK goes low again.

If PCH_PWROK doesn't ever go high, then you know the power-up sequence isn't completing successfully, and you can probe each rail and SLP signal in sequence to see which one is causing a problem.

I would also be happy to take a look at your schematic/ layout if you want to send it to me.

Hi Nick

Please refer to below waveforms with PCH_PWROK when power up.

Is any possible to see what is causing by waveforms?

I am confused that why the PCH_PWROK is high but the VCCGI is low.

According to the cold boot sequence VCCGI should be high.

Thanks

Bruce

Bruce,

It is not unexpected that PCH_PWROK is high while VCCGI is low. VCCGI is initially set to 0V, and then is set to a new voltage by the processor. If VCCGI never goes high I would try checking the Rail 3 SVID ID setting in the Flash Image Tool. It should be set to I2C. 

I think that since we cant see any faults from the PMIC, what might be happening is the processor is not setting the VCCGI voltage, and so it is resetting the PMIC by going through the COLD_OFF sequence, although it is hard to say without actually seeing those SLP signals.

Bruce,

Any update on this?