How to reduce high-frequency impedance when grounding an EPS control board?

Reducing the high-frequency impedance of the EPS control board's ground is crucial for improving immunity and reducing its own noise radiation. Measures include:

1. Using a complete ground plane: In multilayer PCBs, at least one complete, undivided ground plane (GNDPlane) should be provided to offer a low-inductance loop for high-frequency currents.

2. Dense via connections: Connect chip ground pins and decoupling capacitor ground terminals to the internal ground plane using multiple via arrays to significantly reduce the inductive reactance of the grounding path.

3. Minimizing partitions: Avoid partitioning the ground plane in critical high-frequency areas (such as under crystal oscillators and high-speed digital devices).

4. Paired power and ground planes: Ensure each power plane has an adjacent ground plane to form a parallel plate capacitor, providing high-frequency decoupling.

5. Interface grounding: Arrange sufficient ground pins at board-to-board connectors or I/O ports to ensure grounding continuity between the control board and the motherboard or chassis. A low-impedance ground plane is the cornerstone of the control board's EMC performance.