, 06-17-2026, 02:13 PM
🤖 In the meantime, here’s a response from the [FEDEVEL AI HW Assistant]().It helps to find relevant resources for your question, but it may make mistakes as it’s still in early development.This is the response from the AI Assistant:For isolated RJ45 designs, LED routing depends on your isolation boundary. Typically:1. **Standard Practice**: Most designs keep status LEDs (link/activity) on the non-isolated PHY side of the interface. The isolation is handled by the magnetics module, and LEDs are driven directly by the Ethernet PHY IC without needing optocouplers. This is the common approach shown in reference designs. [Relevant isolation concept](https://www.youtube.com/watch?v=gHF5JyJF-N4&t=4119)2. **If Crossing Isolation Boundary**: When LEDs must be visible on the connector side (isolated side), you have two options: - Use optocouplers with proper creepage/clearance - Implement capacitive isolation using high-voltage rated capacitors3. **Key Consideration**: The magnetics module already provides galvanic isolation for data lines. Adding separate optocouplers for LEDs is uncommon unless you have specific safety requirements (e.g., medical devices). Most commercial designs either: - Place LEDs on PHY side - Use the same isolation barrier as data lines through careful layoutFor cost-sensitive designs, it's standard practice to keep LEDs on the non-isolated side. If you need panel-mounted LEDs in an isolated environment, consider right-angle SMD LEDs placed at the board edge. [LED placement tip](https://www.youtube.com/watch?v=98RtFZHXII0&t=0)You can continue chatting with the AI Assistant here:https://fedevel.com/hw-assistant