> For the complete documentation index, see [llms.txt](https://docs.quilter.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.quilter.ai/physics-constraints/single-ended-impedance-control.md).
# Single-ended Impedance Control
Details on specifying and validating single-ended impedance-controlled nets, including supported impedances and calculation methods.
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
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.
To define a high current net constraint, you need to fill in the following fields:
1. Net name
2. Target impedance (we currently support 50Ω and 75Ω)
3. Signal frequency (GHz)
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.
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