How do Dallas Semiconductor delay lines work?

摘要

In the early 1980s, Dallas Semiconductor was the first company to develop the all-silicon delay line (Figure 1). These ICs provided a smaller, more cost-effective alternative to the modular delay lines used at the time. The first Dallas delay lines consisted of an RC-based ramp generator and a comparator circuit that transitioned the delay line output when it reached a certain voltage level on the ramp generator. Calibration was performed at the factory at wafer level by using a laser to blow a series of fuses until the desired delay was achieved. There was limited provision for temperature compensation.