How to design onboard filtering for motion controller MC

The onboard filtering design for the motion controller MC requires differentiated treatment for different circuit modules. Power input filtering includes common-mode inductors, X capacitors, and Y capacitors, such as CMZ series common-mode inductors paired with safety capacitors. LC filters are arranged for the input and output of the switching power supply chip, using shielded power inductors. Decoupling capacitor networks are configured for the power pins of each digital chip, including large-capacity energy storage capacitors and multiple small-capacity MLCCs.

For analog circuits such as the ADC front-end, anti-aliasing filters and common-mode rejection circuits are designed. High-speed signal lines have ferrite beads connected in series and TVS diodes connected in parallel at the connector exit, such as ESDLC series. The clock circuit uses a P-type filter and is grounded. All filtering components should be placed as close as possible to the protected device or noise source, and the ground pin should be connected to the reference ground plane with the shortest path. Avoid parallel and close proximity of filter input and output traces during layout. Optimize filter parameters through simulation to ensure sufficient attenuation in the target frequency band without affecting signal quality. The filtering effect must be verified through board-level testing after design.