TX 1 may not start depending on the power supply source, which is troubling.
It occurred during product start-up test.
For the power supply system 1, start up 100%.
In the case of the power supply system 2, only about 50% is normally activated.
· It is a custom board.
· It adopts Auto-Power_ON mode.
· The power supply of the carrier board is 100% normal.
· The power supply of the carrier board is on, and RESET is negated.
· There is no log output on UART 0.
Is there something the TX 1 does not move while the power management IC is running?
What is the cause?
Please let me know if there are regulations that I must not protect.
Suggest to measure the signals to check if they are same as power up sequence of OEM DG, basically if the VDD_IN input is stable, there should be no such issue if no other difference between your two systems.
Thanks for your advice.
I will try to measure it again.
However, what is stated in OEM_DG is the measured value at P2597, not the standard of Jetson_TX1.
Should not we show standard values even if we review it?
t2-3: 105 [ms]] (VDD_IN ramp to VIN_PWR_BAD #: ‘H’)
t2-4: 330 [ms] (VDD_IN ramp to CHARGER_PRSNT #: ‘L’)
t4-6: 8 [ms] (CHARGER_PRSNT #: ‘L’ to CARRIER_POWER_ON: ‘H’)
t6 - 8: 150 [ms] (CARRIER_POWER_ON: ‘H’ to RESET_OUT #: ‘H’)
However, Tegra_X1 may not start.
A voltage detection IC is connected to RESET_OUT #.
Since the rise of 1.8 V is fast, the delay time setting is set to 5 [ms].
Therefore, the above 150 [ms] is almost the assertion time of TX 1.
Started when delay time setting is extended. (100% start up so far)
Is there a minimum time to assert RESET_OUT # on the board side?
OEM_DG is not written as asserting on the carrier board side as stipulated by RESET_OUT #.
The minimum value of RESET_OUT # is also not described.
Only the regulation for 1.8 V is written.
Observe that RESET_OUT # (min) = RESET_IN # (min).
Is it better than 50 [ms]?
The TX1 takes a hefty bit of current to power on, if you use a supply that’s not up to the task you might see the fan twitch but nothing else. We’ve seen that quite a few times during testing if we try to use too small a regulator.