How to prevent external interference in a motion controller MC single-ended pulse?

To protect the single-ended pulse signal of the motion controller MC from external interference, enhanced filtering, shielding, and grounding are necessary. A Schmitt trigger is used for shaping at the pulse input; its hysteresis voltage suppresses small-amplitude noise. An RC low-pass filter is added before the Schmitt trigger, with the time constant set according to the pulse frequency. A TVS diode is connected in parallel to suppress high-voltage transients. Shielded pulse lines must be used, with the shield grounded at the receiving end.

On the PCB, pulse traces should be as short as possible and encased in ground. For long-distance transmission, a series resistor can be connected at the transmitting end to dampen reflections, and impedance matching can be performed at the receiving end. Avoid running pulse lines parallel to power lines. Provide a separate, clean power supply for the pulse circuit and isolate it from the digital power supply via a ferrite bead. In software, digital filtering and validity verification of the pulse signal can be performed. Simulated field interference testing ensures reliable identification of the single-ended pulse in noisy environments.