Discharge Circuit for Jetson Orin Nano Carrier Board

Issue Overview

The discussion revolves around the design of a custom carrier board for the Nvidia Jetson Orin Nano, specifically addressing concerns related to the discharge circuit requirements for the power supply voltages of +3.3V and +1.8V. Users are experiencing uncertainty regarding the specifications outlined in the document “DG-10931-001_v1.2.pdf,” which states that the +3.3V rail must discharge to 0V within 1.5 milliseconds or less, and the +1.8V rail must do so within 4 milliseconds or less.

The main symptoms include confusion about what percentage of voltage is considered acceptable during the discharge process, with users questioning whether the discharge time refers to a drop to 90% or 95% of the specified voltage levels. This issue arises during the design phase of custom hardware and could significantly impact the functionality and safety of the carrier board.

The frequency of this issue appears to be isolated to users involved in custom hardware design for the Orin Nano, indicating that it may not be a widespread problem but rather a specific concern for developers working on similar projects.

Possible Causes

• Misinterpretation of Specifications: Users may misinterpret the discharge time requirements, leading to confusion about what voltage level is expected at specified times.

• Documentation Clarity: The specifications in “DG-10931-001_v1.2.pdf” may lack clarity regarding voltage thresholds during discharge, contributing to user uncertainty.

• Design Errors: Inadequate understanding of electrical engineering principles related to discharge circuits could lead to improper design choices that do not meet the required specifications.

Troubleshooting Steps, Solutions & Fixes

1. Review Documentation:

   • Revisit “DG-10931-001_v1.2.pdf” and ensure all specifications are clearly understood, particularly those related to discharge times and voltage levels.

2. Consult Electrical Engineering Principles:

   • Understand basic principles of capacitor discharge circuits, including how voltage drops over time and how this relates to your specific application.

3. Calculate Discharge Time:

   • Use the following formula to estimate discharge time based on your circuit configuration:
     $$ V(t) = V_0 \cdot e^{-\frac{t}{RC}} $$
   • Where $$ V(t) $$ is the voltage at time $$ t $$, $$ V_0 $$ is the initial voltage, $$ R $$ is resistance, and $$ C $$ is capacitance.

4. Simulate Circuit Behavior:

   • Utilize circuit simulation software (e.g., LTspice or similar tools) to model your discharge circuit and visualize how quickly voltages drop over time.

5. Test with Prototype:

   • If possible, create a prototype of your carrier board with a focus on testing the discharge circuit under controlled conditions to observe actual performance against documented requirements.

6. Seek Community Input:

   • Post specific questions or findings in forums or communities focused on Nvidia Jetson products or custom hardware design for additional insights from experienced developers.

7. Documentation Updates:

   • If discrepancies in documentation are found, consider reaching out to Nvidia support or relevant forums to suggest clarifications for future versions of technical documents.

By following these steps, users can better understand and address issues related to discharge circuits in their custom carrier board designs for the Nvidia Jetson Orin Nano.