What are the factors that affect SOC startup?

I made a TX2 carrier board based on the B04 schematic, but it cannot be powered on. I checked the power supply circuit against the circuit diagram and there is no problem with the connection. The current phenomenon of the circuit is:

1.VDD_MOD has voltage directly to SOC;
2. There is no voltage on the VDD_PWR_BAD pin;
3. After plugging in the power supply, pin A48 has a voltage of 1.14V;
4. What effect does this part of the circuit of POWER MONITIORS have on power-on (the manual does not explain the principle and level of this part of the circuit)

I want to know, what are the factors that affect SOC startup?

Hi, please capture a full power up sequence as that in OEM Design guide so that we can investigate the possible issue. In addition, there is a checklist table in OEM DG, you can check the design first based on that.

I I read the checklist carefully, and it shows that VDD_PWR_BAD# needs an external pull-up to 3.8V?

Here is the external pull-up, do I need to make a pull-up circuit on the carrier board?

No, it is typo that will be corrected. There is internal pull-up in module. VIN_PWR_BAD# should go high before power on, otherwise system will no power on.

I have two questions:

  1. I designed the carrier board according to the B04 schematic diagram. Now A1 A2 B1 B2 C1 C2 is a stable 19V voltage, but the VDD_PWR_BAD# pin of the module has no high level output.

  2. The TX2 kit I bought is wearing a C02 carrier board. Will the system be incompatible with the B04 carrier board?

Do you think VDD_PWR_BAD has no high-level output?

VIN_PWR_BAD# is not output from module, it is an input to module to indicate VDDIN is stable. Please read OEM DG carefully, especially on power part to eliminate the difference between your design and reference design. Both B04 and C02 design are suitable to TX2 module as you can see in OEM DG.

What I said is wrong, I want to express that VDD_PWR_BAD# is not outputting high level.

When VDD_MOD is given to SCO’s A1 A2 B1 B2 C1 C2, I measured the level of the B8 pin as low. I looked at the timing issues in EMO DG and found that after powering on the SOC (VDD_MOD), B8 should read a high level (measure the B8 pin should be high).

In my actual measurement kit, the board is also, after VDD_MOD is powered on, the B8 pin (VDD_PWR_BAD#) measures a 5V voltage.
But in the board I made, after VDD_MOD is powered on, the B8 pin has no voltage value (VDD_PWR_BAD = 0).

I measured the 3 pins of Q31.

Please check your design and compare to reference, VIN_PWR_BAD# should be low first and goes high after 19v input is stable, there is RC circuit to guarantee this.

Okay, thank you very much, let me focus on the power supply circuit;

Are there other circuits that affect SOC startup?