EMC Question of the Week: September 7, 2026
A small (4-cm x 3-cm) sensor board communicates with a controller board using a pseudo-differential interface (e.g., USB or CAN). The cable connecting the two devices is a shielded twisted wire pair. The cable shield is connected to the chassis ground at the controller end, but the sensor board is in a plastic enclosure with no metal chassis. In this case, the shield of the cable should connect to the sensor board ground plane through
- nothing (open circuit)
- connector pins (short circuit)
- TVS diodes
- ferrites