This guide explains proper grounding techniques for data converters to resolve AGND and DGND confusion in mixed-signal systems.
This document serves as a guide for engineers to correctly implement grounding for data converters, specifically addressing the confusion between Analog Ground (AGND) and Digital Ground (DGND). It covers the importance of ground and power planes, decoupling strategies for low and high frequencies, and PCB design considerations for both two-layer and multi-layer boards.
The guide further details grounding strategies for multi-card mixed-signal systems, including star and multi-point grounding concepts. It provides specific advice on separating analog and digital ground layers to minimize noise coupling, and explains how to handle mixed-signal ICs with low digital currents by treating them as analog components for grounding purposes. This manual is written in Chinese.
The DC or AC voltage between the two ground layers must be less than 300 mV to avoid damaging ICs.
There is approximately 0.2 pF of stray capacitance between each pin of an IC package.
Connector pins should be at least 30 to 40% dedicated to ground.