How to select the MC pulse port protection for motion controllers

Selecting protection devices for the MC pulse port of a motion controller requires comprehensive consideration of signal speed, voltage level, and potential interference types. For high-speed pulse signals, low-capacitance TVS diode arrays, such as the ESDLC series, must be selected, with capacitance as low as a few pF, to avoid affecting signal edges. The operating voltage VRWM should be slightly higher than the high level of the pulse signal. The peak pulse current IPP of the TVS should be determined based on the potential ESD, EFT, or surge levels.

For lightning strike induction introduced by long cables, gas discharge tubes may be needed as a primary coarse protection. In areas with dense connector pins, multi-channel integrated protection arrays can be selected. Simultaneously, a low-resistance PTC or resistor can be connected in series on the signal line to limit current. After selection, testing in an actual circuit is necessary to verify the clamping effect of the protection device under applied interference and ensure that it does not affect the integrity of the pulse waveform during normal operation.