# Single-ended Impedance Control

This constraint enables impedance-controlled routing for RF nets and other fast, long, or sensitive traces. 

### Automatic Detection

* Currently, single-ended impedance nets can only be entered manually.

### Constraint details

<figure><img src="/files/C6pFK40Zqn9MZpIH9ZyG" alt=""><figcaption></figcaption></figure>

Single-ended impedance control can be applied to nets in the "Single Ended Impedance Signals" section of Circuit Comprehension. You can add them one at a time, match them using regex, or apply a netclass. &#x20;

To define a high current net constraint, you need to fill in the following fields: &#x20;

1. Net name &#x20;
2. Target impedance (we currently support 50Ω and 75Ω) &#x20;
3. Signal frequency (GHz) &#x20;

Quilter will automatically perform the impedance control calculations that take into account the specified stack-up's material properties to determine the correct trace width necessary to achieve the specified impedance within a tolerance of 5%.

### Physics Rule Checks

The following PRCs validate this constraint after compilation:

**Invalid Width Span** determines the length of trace paths in a net are outside of an acceptable tolerance threshold. A trace segment has an “invalid width” if its width is outside of a 10% tolerance when compared to the nominal value.

**Ground Plane Overlap** determines if the ground plane below net traces overlaps at all relevant points.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.quilter.ai/physics-constraints/single-ended-impedance-control.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.