UCD90160A: Cannot resequence after a TON_MAX fault

Hello

I would suggest to set the resequencing time to unlimited instead of 4 time and also increase the sequencing interval to try? if this does not help,  please share your project file.

Regards

Yihe

Hello Yihe,

Following your advices I was able to have some resequencing on the eval board.

But I cannot get it to resequence on our board, which of course have different timing because it based on real supplies.

Is there a secure way to share our project file.

Best Regards,

L.B.

Hello

 On the monitor tab or system monitor page, what's state of the rail, IDLE, SEQ_ON or others?

you may  check the dependencies of the rails to make sure that they are good to turn on the rails.

You can contact your local TI sale to forward project file.

Regards

Yihe

Hello Yihe,

Thank you for your quick reply, I will try my best today to work on the subjet with your inputs, but I also requested on another matter.

I will transmit the project file through the French AFE : P. R.

Best regards,

L. B.

Hello Yihe,

Your advices allow me to have a first working version. I went back on evaluation board which allow me to correct some little mistakes and then I was able to have it working on my real board. I validated it today, I'm waiting now for internal feedback.

I was requested to check GND with a monitor pin, we could read through the PMbus. The only solution I have found is to have a high power good level which disables under voltage faults. But it is generating an alert on the UCD anyway. Do you have a solution for this other point ?

Thank you for your help,

Best regards,

L. B.

Hello,

Sorry for the delay but I was out of office.

So far now everything is working correctly, expect the GND check with the MON input, which generates an alert and a red LED on my board.

I know, I could have check the level with a GPI, but the requirement I have, is to check a known good voltage with a MON pin to verify that the UCD is working correctly.

So a proposal was to check GND with a MON pin, but the result is an alert.

Do you have an idea to avoid this alert problem or another way to check another voltage available on the UCD to verify the internal ADC.

Thank you for your help,

Best regards.

L.B.

Hello

What're the MON threshold settings for the GND?  is GND signal always 0V or it would be something other than 0V?

Regards

Yihe

Hello Yihe,

Thank your for your reply.

The max voltage measured as GND has a maximum of 30 mV due to noise (reported by the UCD).

My thresholds voltage are Margin High 40 mV, Over Warn 80 mV, Over Fault 120 mV; Margin Low 0 mV, Under Warn 0 mV, Under Fault 0 mV (because they cannot be negatives)

To avoid always record faults, I have programmed the Power Good On at 100 mV and Power Good Off at 50 mV.

This globally disables the rail (and the fault checking) because the rail remains in RAMP_UP state. This is fine for me  because we just want to be able to measure the rail through the ADC using our GPP with the PMbus.

The only problem is that the global POWER_GOOD is diasserted so the alarm pin is turn on : our red LED in always ON.

I hope you I have describe everything.

Best Regards,

L. B.

Hello

Have you tried to set the VOUT CAL MON the same as POWER_GOOD_ON threshold?

Regards

yihe

Hello Yihe,

Sorry for the delay, I could not try directly your proposal. It didn't work straight with a 100 mV for Vout Col Mon for a 100 mV Power Good On, but it did work for

for a value of 20 mV for Vout Col Mon. Now the Alert RED doesn't light on on startup.

I still have a trouble, which can probably be solved. When I cut the power supply a 5 V one, the UCD detect it and report as a fault whereas it is the normal shut down procedure.

Is there a way to avoid recording a Under Voltage Fault when a certain voltage drops and sequence a normal shutdown of all other rails.

Thank you for your help,

Best Regards,

L.B.