USB_VBUS_EN0 Usage and Configuration on Jetson Orin Nano

Issue Overview

Users are seeking clarification on the purpose and usage of the USB_VBUS_EN0 pin on the Jetson Orin Nano developer board. There is confusion about whether this pin is required for operation and how to handle it in custom designs that may not utilize all USB functionalities. This issue is particularly relevant for developers creating custom hardware designs based on the Jetson Orin Nano module.

Possible Causes

1. Lack of documentation: The purpose and requirements of USB_VBUS_EN0 may not be clearly explained in the available documentation.
2. Custom hardware design considerations: Developers creating custom carrier boards may be unsure about how to handle unused USB-related pins.
3. Misunderstanding of USB power management: There might be confusion about the role of VBUS in USB interfaces and when it needs to be enabled.

Troubleshooting Steps, Solutions & Fixes

1. Understand the purpose of USB_VBUS_EN0:

   • USB_VBUS_EN0 is the enable signal for the USB VBUS (bus voltage) as mentioned in the Jetson Orin Nano Design Guide.
   • It is used to control the power supply to USB devices connected to the port.

2. Determine if USB_VBUS_EN0 is required for your design:

   • If your product includes physical USB ports that need to supply power to connected devices, you should use USB_VBUS_EN0 to control the VBUS power.
   • If your design does not include physical USB ports and only uses USB interfaces for communication, you may not need to use USB_VBUS_EN0.

3. Handling USB_VBUS_EN0 in custom designs:

   • If USB functionality is not used or if VBUS power control is not required:
     • You can leave the USB_VBUS_EN0 pin unconnected.
   • If USB functionality is used and VBUS power control is needed:
     • Connect USB_VBUS_EN0 to the appropriate power management circuitry to control VBUS power for USB devices.

4. Consult the Jetson Orin Nano Design Guide:

   • Review the official design guide for detailed information on USB implementation and pin usage.
   • Look for specific sections related to USB power management and VBUS control.

5. Best practices for custom designs:

   • Always refer to the latest Jetson Orin Nano documentation when designing custom carrier boards.
   • If in doubt about any pin functionality, consult NVIDIA’s developer forums or support channels for clarification.
   • Consider future expandability: Even if current designs don’t use USB ports, leaving provisions for USB_VBUS_EN0 might be beneficial for future revisions.

6. Testing USB functionality:

   • If you’re unsure about the impact of leaving USB_VBUS_EN0 unconnected, test your design thoroughly to ensure all required USB functions work correctly.
   • Use appropriate test equipment to verify VBUS voltage levels and USB communication if applicable to your design.

By following these steps and guidelines, developers can properly handle the USB_VBUS_EN0 pin in their Jetson Orin Nano-based designs, ensuring correct USB functionality where required and avoiding unnecessary complications in designs that don’t utilize USB ports.