High Frequency Transmission Lines
|
• A trace may need to be treated as a transmission line when trace length >
λ / 20, or propagation delay > (pulse rise time)/4.
• Use a Z0 > 40 Ω to minimize the drive current and a Z0 < 120 Ω to reduce emission and susceptibility.
• Unintended sharp transitions in signal level may indicate reflections due to impedance mismatches.
• The time delay for the arrival of a reflection may indicate the distance to the impedance mismatch.
|
