Edge Rate Calculator
Analyze signal edge rates and transmission line effects
Signal Parameters
Analysis Results
⚡ Transmission Line: Moderate - consider termination
Rise Time
1.00
ns
Edge Rate
3.30
V/ns
Knee Frequency
350
MHz
Critical Length
41.8 mm
Flight Time
0.342 ns
Flight/Rise Ratio
0.34
λ at f_knee
418.2 mm
Recommendation: Trace exceeds critical length (41.8 mm). Use controlled impedance and consider series or parallel termination. Min rise time for this trace: 1.37 ns
Typical Edge Rates by Technology
| Technology | Rise Time | f_knee | Critical Length |
|---|---|---|---|
| Standard CMOS (3.3V) | 2-5 ns | 70-175 MHz | 80-200 mm |
| LVCMOS (1.8V) | 1-3 ns | 115-350 MHz | 40-120 mm |
| LVTTL | 2-4 ns | 90-175 MHz | 60-150 mm |
| LVDS | 0.3-1 ns | 350 MHz - 1.2 GHz | 10-40 mm |
| DDR4 | 0.2-0.5 ns | 700 MHz - 1.75 GHz | 8-20 mm |
| PCIe Gen3 | ~0.1 ns | 3.5 GHz | ~4 mm |
The λ/10 rule: When trace length exceeds λ/10 at the knee frequency, treat it as a transmission line. Faster edges create higher frequency content and require shorter critical lengths.
Need Signal Integrity Analysis?
Our engineers ensure clean signals in your high-speed designs.
Get Free Quote