A physical structure, such as a coiled PCB trace, a length of coaxial cable, or a dedicated IC, used to introduce a specific propagation delay into a signal path. They are used to align timing between parallel high-speed buses, synchronize video signals, or filter out transients. In high-speed digital design, delay lines are often implemented as precisely matched serpentine traces on the motherboard.
Heard on the job
We need to route a 50-picosecond delay line on the clock trace so it matches the data bus arrival time.