HDMI Series Resistor Requirement for Orin Nano with HDMI 1.4 Devices

Issue Overview

Users of the Nvidia Jetson Orin Nano are seeking clarification on the necessity of series resistors for HDMI connections, specifically when interfacing with devices that only support HDMI 1.4. The Orin Nano Design Guide mentions the requirement of series resistors for HDMI 2.0 compliance, but it’s unclear whether these are needed for older HDMI standards.

Possible Causes

1. Design Guide Ambiguity: The Orin Nano Design Guide may not explicitly address HDMI 1.4 requirements, leading to confusion among users.

2. Different HDMI Version Requirements: HDMI 2.0 and 2.1 have different electrical specifications compared to HDMI 1.4, which could necessitate different circuit designs.

3. Backward Compatibility Concerns: Users may be unsure if the Orin Nano’s HDMI output needs additional components for proper functioning with older HDMI standards.

Troubleshooting Steps, Solutions & Fixes

1. Confirm HDMI Version Requirement:

   • Determine the HDMI version supported by your downstream device (e.g., monitor, TV).
   • If your device only supports HDMI 1.4, proceed with the following information.

2. Series Resistor Requirement:

   • For HDMI 1.4 connections, series resistors are not required on the HDMI lines of the Orin Nano.
   • The official response confirms: "No need for HDMI1.4."

3. Design Considerations:

   • When designing a custom carrier board for the Orin Nano:
     • Omit series resistors on HDMI lines if you’re only targeting HDMI 1.4 compatibility.
     • If future-proofing for HDMI 2.0, consider adding footprints for series resistors that can be populated as needed.

4. Referencing the Design Guide:

   • Consult page 56 of the Orin Nano Design Guide for detailed information on HDMI specifications.
   • Note that the guide states: "Series Resistor (RS): Series resistor on P/N path for HDMI 2.0 but not required for HDMI 2.1 (Mandatory to meet HDMI 2.0 Compliance)."

5. Best Practices:

   • Always refer to the latest version of the Orin Nano Design Guide for the most up-to-date information.
   • If designing for multiple HDMI versions, consider a flexible layout that can accommodate different requirements.
   • When in doubt about specific hardware configurations, consult NVIDIA’s official documentation or seek clarification through their developer forums.

By following these guidelines, users can correctly implement HDMI connections for the Orin Nano when working with HDMI 1.4 devices, ensuring proper functionality without unnecessary components.