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PF3001+IMX6ULL temperature shutoff mechanism for longer duration

Question asked by Vivek Rajpara on Sep 27, 2019
Latest reply on Oct 18, 2019 by gusarambula

Hi,

 

We have a requirement of temperature shutoff mechanism with IMX6ull + PF3001, we need help in root causing one issue as described below. Looking forward to a helping response to the issue.

 

 

Set up:

We are keeping the device ON at 85 deg C constant temperature for 15 -16 hours. In this condition except for PMIC, MPU, and DDR, all other components are in powered off. The device should be recovered when the temperature comes below 70 deg C.

 

Issue:

If we increase the temperature of PCB up to 85 deg C and keep for a shorter duration like 1-2 hours. In this condition, the processor is successfully able to come out of this U-Boot condition when the temperature cools down to 70 degC.

It doesn't work properly if we keep PCB 85 deg C for longer duration like 8-15 hours (Randomly observed in 9 hours, 13 hours in 2 devices). In this condition, it is not coming to the normal condition even after cooling down the system to 70 deg C.

 

Analysis:

-> When we observe SOC_IN and HIGH_IN power, they are off when the issue is reproduced although PMIC input is proper and uninterrupted.

-> PMIC_POWERON_REQ line is becoming 0 in this condition.

-> PMIC case temperature is 86deg C constant throughout the test.

-> IMX6ULL case temperature is 87deg C constant throughout the test.

 

Questions:

1) Is there any condition where MPU turn off PMIC_POWERON_REQ line?

2) Is there any way PMIC goes in shutoff mode for a longer duration if the temperature cycle lasts ( i.e. 85 C for more than 16 hours)

3) Is there any temperature condition in which the processor stops working and shut itself.

4) There is PANIC temperature alarm in the IMX6ULL TEMPMON section, which resets the system.

      -> Will PMIC_POWER_ON_REQ PIN turned off when PANIC alarm condition generates Chip reset signal?

      -> How can we calculate time after which PANIC alarm resets the chip once the temperature reached to PANIC threshold?

 

Thanks,

Vivek

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