We are designing a custom Carrier Board.
I am worried about the power startup timing of the Carrier Board.
So I decided to turn on the Carrier Board 100ms after POWER_EN.
The reason is that the actual measured time from POWER_EN to SYS_RESET was 13ms.
Do you think it is enough to have a 100ms period?
Controlling the power of the carrier board with SYS_RST causes inconvenience.
Because it uses SYS_RESET for the RESET pin of some ICs on the carrier board.
This is an improper sequence in which the power turns on after the RESET is released.
I’m sorry I wasn’t good at explaining.
Of course, it’s okay to control the carrier board’s power supply with SYS_RST,
However, it is not possible to reset the peripheral IC with SYS_RST.
The power sequence of most ICs in the world is RESET release after power on.
It depends on your design. If you are sure about the timing (100ms?) from POWER_EN to carrier power rails on is enough for module power on, then you can implement the delay to your design.
If my understanding to your question is correct: as you can see, SYS_RESET is used to the EN of carrier power supply not the RESET of the chip. So it needs to add delay design between carrier power supply and the RESET of chip on carrier.