VCC_SRC and VCC_SRC_FET on Orin Carrier board

Hi, on P3737_A04 SCH,

  1. what does SRC of VCC_SRC stand for?
  2. what is the time delay between VCC_SRC and VCC_SRC_FET?
  3. Why is NC301 (U69) used to detect VCC_SRC_FET, not VCC_SRC?
  4. VIN_PWR_BAD_N is output of U69, which means VIN_PWR_BAD_N will be de-asserted after VCC_SRC_FET is detected. VIN_PWR_BAD_N is pulled up by 5V on the module according to DG of Orin module figure 5-1. So VIN_PWR_BAD_N will not be high until internal 5V is established. So what is the time delay between VCC_SRC (SYS_IN_HV) and internal 5V?
  5. If DC jack is plug in First and then plug a USBC power supply later, which power will be selected as the power supply? how does this selection happen(in another words, what is the working principle behind this)?
    Thanks, Jason

Hi, we are checking on these internally, will update once available.

Please refer to below comments:

  1. SRC = Source. It’s a netname to differentiate from other netnames.

  2. VCC_SRC_FET will be ON once the power adapter is plugged. It’s like an “always-ON” power rail. VCC_SRC is turned on by button. (If is configured as auto-power-ON, VCC_SRC is also turned on by ‘emulated’ button: ACOK)

  3. Want to assert VIN_PWR_BAD_N ASAP to buy more time for elegant power off once the input power rail drops to certain level. VCC_SRC comes from VCC_SRC_FET thru MOSFET.

  4. The module has no sequence requirement on the delay SYS_IN_HV and SYS_IN_MV, either can be ON first. P3737 turn on VCC_SRC first, then 5V. For example, the delay between VCC_SRC and 5V is ~7.8ms at 20V, ~2.5ms at 12V.

  5. DC Jack will be selected the power supply. It will let the first power supply through. In other words, First come first serve.

Thanks Trumany.
For question 4, further question is ON DG-10653-001 V1.1, section 5.3.1 Auto Power-ON, does this section talk about the No-MCU solution for power up? If it is, can you provide design details or reference design about how to implement No-MCU Auto power-on circuit?
For question 5, would you please elaborate the details of how U513(CYPD4226) detects power DC jack power supply (if it comes first) and disregard the input from USBC port? and vice versa.

The Auto power-on part is for No-MCU, there is no reference design as customer only needs to follow the requests as listed in the part. For the U513 question, it is a validated function design, customer just needs to replicate it if necessary, no more info of this kind of 3rd-party device can be shared.

Thanks Trumany, i saw another thread below saying Orin has not yet support No-MCU design. It contradicts with the your reply above. would you double check and advise if No-MCU Auto power-on is supported by Orin module?

Checked internally, the auto power on part is not for no-MCU design. Currently, there is no no-MUC design reference.

Thanks Trumany.
Based on your reply, my understanding is that DG Section 5.3.1 Auto power-on is not for no-MCU design, so what is section 5.3.1for? is it reserved for future use?
If I need to design auto-power-on, Would you confirm that I have to follow MCU design on the carrier board Schematic and refer to Section Auto-power-on case on DG?

It is the simplest requirements for Auto Power-on connections/sequence requirements. Currently please follow MCU design only.