Regarding the “SLEEP/WAKEn” pin pull-up on the Orin Nano carrier board

Issue Overview

The discussion revolves around a potential design issue related to the pull-up configuration of the "SLEEP/WAKEn" pin on the Nvidia Jetson Orin Nano carrier board. Users are experiencing uncertainty regarding whether having a pull-up resistor connected to the VDD_5V_SYS power rail while the Jetson module is powered off could lead to problems.

Specific Symptoms or Errors

• Users are concerned about whether the signals associated with the Jetson module should be HIGH or have pull-ups when the module is powered off.
• There is confusion regarding the implications of the schematic showing a pull-up resistor (10K) connected to VDD_5V_SYS.

Context of the Problem

• The issue arises during the design phase of custom carrier boards for the Orin Nano.
• The design guide indicates that signals should not be HIGH when powered off, which contradicts the schematic showing a pull-up.

Hardware and Software Specifications

• The discussion references specific documents:
  • Design Guide “DG-10931-001_v1.2.pdf”
  • Schematic “P3768_A04_Concept_schematics.pdf”

Frequency and Impact

• The issue appears to be a one-time concern during board design rather than a recurring operational problem.
• If misconfigured, it could potentially affect how power management functions in custom designs, impacting user experience and system functionality.

Possible Causes

• Hardware Incompatibilities: The configuration may not align with standard practices for power management in custom designs.

• Software Bugs or Conflicts: If there are discrepancies between documentation and actual behavior, it could lead to unexpected issues.

• Configuration Errors: Incorrectly following design guidelines could lead to improper signal handling.

• Driver Issues: If drivers expect certain conditions that are not met due to hardware design, it could lead to malfunctions.

• Environmental Factors: Power supply variations could affect signal integrity if not designed properly.

• User Errors or Misconfigurations: Misinterpretation of documentation might lead users to implement incorrect designs.

Troubleshooting Steps, Solutions & Fixes

1. Review Documentation:

   • Ensure that both the design guide and schematic are understood fully. Pay close attention to sections discussing power management and signal states when powered off.

2. Check Pull-Up Configuration:

   • Confirm that having a pull-up resistor connected to VDD_5V_SYS is acceptable for your specific application. It was noted in replies that this configuration is intended for power button functionality.

3. Testing Signal States:

   • Use an oscilloscope or multimeter to measure the state of the SLEEP/WAKEn pin during power-off conditions to verify if it behaves as expected.

4. Isolation Testing:

   • Create a prototype of your custom carrier board without the pull-up resistor and test its functionality under various scenarios (e.g., powered on, powered off).

5. Consult Community or Support:

   • If uncertainties persist, consider reaching out on forums dedicated to Nvidia Jetson products for additional insights from other users who may have faced similar issues.

6. Documentation Updates:

   • If discrepancies between documents are found, consider reporting these to Nvidia for clarification and potential updates in future revisions of design guides.

7. Best Practices for Future Designs:

   • Always cross-reference multiple sources of documentation when designing custom hardware.
   • Follow community discussions and updates regarding common issues with specific hardware configurations.

Recommended Approach

It was noted that having a pull-up resistor for power button functionality does not pose a problem, suggesting that this approach can be safely implemented in designs unless otherwise indicated by specific operational requirements.