How are the power ground and signal ground separated in a power FTU?

Separating power ground and signal ground prevents high-current noise from interfering with sensitive circuits. A single-point connection method is used after grounding. Power ground (PGND) is used for power conversion and motor drive; signal ground (SGND) is used for sampling and communication. Both are connected at a single point near the DC-DC output using a PBZ1608A-102Z0T ferrite bead (1000Ω@100MHz) or a 0Ω resistor. PCB design: Power ground has complete copper plating with trace width meeting current requirements (1mm/1A); signal ground uses a grid-like copper plating to reduce antenna effect. Digital ground and analog ground are separated by ferrite beads. Chassis ground (CGND) is connected to earth ground via a low-impedance path. This design reduces ground noise by more than 20dB, meeting the IEC 61000-4-8 power frequency magnetic field immunity test requirements.