How to protect against fast pulses in motion controllers MCEFT?

To protect the motion controller MC from EFT (Electronic Fast Transient) bursts, dedicated EFT filters must be installed at the ports. Common-mode chokes, such as the CML series, along with safety-certified Y capacitors, should be used at all external connection ports, including power, communication, and I/O ports, to bypass high-frequency common-mode noise to ground. Power ports require additional X capacitors and differential-mode inductors. Signal ports can be filtered with RC filters or ferrite beads after TVS diodes.

PCB layout is crucial; port filter grounds must be connected to a clean "quiet ground," which is connected to the internal circuitry ground via a single point. Internally, local LC filters or LDOs should be added to the power supply for sensitive chips. For digital inputs, Schmitt triggers should be used in conjunction with software debouncing. Communication protocols should include frame check and retransmission. During testing, follow IEC 61000-4-4 standards, monitoring critical signals, identifying coupling paths, and optimizing filter parameters and grounding. Iterative improvements are typically required to achieve a high level of protection.