How to design the MC interface isolation for motion controllers

The interface isolation design for a motion controller (MC) requires selecting a solution based on isolation requirements and signal type. For digital I/O, optocouplers or digital isolators are used. For analog signals, isolation amplifiers or isolated ADCs are used. For communication buses, isolated transceiver modules are used. Key steps include: determining the isolation voltage level; providing isolated power to the isolation side, typically using isolated DC-DC modules; implementing the isolation layout on the PCB, with isolation devices connected across isolation strips and ground planes completely separated on both sides; selecting isolation devices that meet signal bandwidth and accuracy requirements; and properly handling filtering and protection of the isolation interface to prevent transient damage to the isolation barrier. After design, withstand voltage testing, insulation resistance testing, and functional testing are required to verify the accuracy of signal transmission and anti-interference capability under isolation. Isolation design can effectively solve ground loop, common-mode interference, and potential difference problems, improving system reliability, but it increases cost and complexity.