Increased RTC Battery Backup Current in Jetson Orin Nano

Issue Overview

The Jetson Orin Nano developer board has experienced a significant increase in the Real-Time Clock (RTC) battery backup current consumption. Initially reported to be 2μA, similar to the original Jetson Nano, the recently released datasheet for the Orin Nano now states a current consumption between 12μA and 50μA. This substantial increase has implications for power management strategies, particularly for users planning to implement super-capacitor solutions for RTC backup.

Possible Causes

1. Hardware Design Changes: The Orin Nano may have undergone design modifications that resulted in higher power requirements for the RTC circuit.

2. Enhanced RTC Functionality: Additional features or improved precision in the RTC module could contribute to increased power consumption.

3. Power Management Adjustments: Changes in the overall power management strategy of the Orin Nano might affect the RTC backup current.

4. Measurement Methodology: The discrepancy could be due to changes in how the RTC current is measured or specified in the datasheet.

5. Environmental Factors: The new specifications might account for a wider range of operating conditions, leading to a broader current consumption range.

Troubleshooting Steps, Solutions & Fixes

1. Verify Datasheet Information:

   • Confirm that you are referring to the latest Jetson Orin Nano datasheet (DS-11105-001_v1.0 or newer).
   • Check for any errata or updates on the NVIDIA Developer website that might address this discrepancy.

2. Measure Actual Current Consumption:

   • Use a high-precision multimeter to measure the RTC backup current on your Orin Nano board.
   • Compare your measurements with both the old and new specifications to determine the actual consumption.

3. Contact NVIDIA Support:

   • Reach out to NVIDIA Developer Support for clarification on the increased current consumption.
   • Inquire about any potential firmware or software updates that might optimize RTC power usage.

4. Explore Alternative Power Solutions:

   • If super-capacitor solutions are no longer viable, consider using a small lithium battery for RTC backup.
   • Investigate low-power RTC modules that can be externally connected to the Orin Nano.

5. Optimize System-wide Power Management:

   • Review and adjust power management settings in the NVIDIA Jetson Linux distribution.
   • Use the following command to check current power mode:

     sudo /usr/sbin/nvpmodel -q
     

   • Set the board to a lower power mode if RTC backup is critical:

     sudo /usr/sbin/nvpmodel -m 1
     

6. Monitor Temperature and Voltage:

   • Higher temperatures can increase current consumption. Ensure proper cooling for the Orin Nano.
   • Check input voltage stability, as fluctuations might affect RTC current draw.

7. Implement Software-based Time Synchronization:

   • If RTC backup is not critical for your application, consider using network time synchronization (NTP) instead.
   • Install and configure NTP:

     sudo apt-get install ntp
     sudo systemctl enable ntp
     sudo systemctl start ntp
     

8. Design Considerations for Production:

   • If developing products based on the Orin Nano, factor in the higher RTC current when designing power supplies and battery backup systems.
   • Consider implementing a hybrid solution using both a super-capacitor and a small battery to balance short-term and long-term RTC backup needs.

9. Stay Informed:

   • Regularly check the NVIDIA Developer Forum and documentation for updates or community-driven solutions to this issue.
   • Subscribe to NVIDIA Developer newsletters to receive notifications about important updates and changes to Jetson products.