How are the analog and digital grounds handled in edge computing boxes?

Edge computing boxes contain high-precision ADC analog circuits and high-speed digital circuits. Improper ground plane segmentation can introduce crosstalk. The correct approach is to unify the analog ground (AGND) and digital ground (DGND) on the PCB without segmentation, but connect them at a single point through a ferrite bead or 0Ω resistor for low-frequency isolation. Recommended ferrite beads are PBZ1608E600Z0T (PB for 1608, size 1.6×0.8mm, E600 for 60Ω impedance, Z for DC with no resistance, high RF with high resistance). Simultaneously, the ground plane below the ADC chip should remain intact. Digital ground noise should be channeled into the analog ground area through the ferrite bead. It is essential to ensure that analog current does not flow through the digital area. Furthermore, all analog signal wiring should be kept away from clock lines and surrounded by ground lines. If the edge box requires extremely high isolation, isolation amplifiers or transformers can be used to separate the ground plane, but this is more expensive. In practice, using a single-point grounding scheme with ferrite beads increased the effective number of bits of the 12-bit ADC from 9.2 to 11.1.