Study on grounding for mixed signal circuits

• Main Author: Tan, Clement Jun Quan.
• Other Authors: See Kye Yak
• Format: Final Year Project
• Language: English
• Published: 2012
• Subjects: DRNTU::Engineering::Electrical and electronic engineering::Electronic circuits
• Online Access: http://hdl.handle.net/10356/49619
• Institution: Nanyang Technological University

Electromagnetic radiation has been a source of problem for engineers as devices operate at higher speed and is required to be smaller in size. In this report, EM radiation in a mixedsignal circuit will be studied in depth from a grounding perspective. Various literature recommend the use of a full ground plane to allow return currents to flow in a smallest current loop as loop area determines a magnitude of the radiation.In this final year project, a simple mixed signal circuit was designed and its near-field and far-field radiation measured and compared to FCC Part 15 Subpart B (3m) standards for reference. While maintaining the component and power plan layout consistent throughout all designs, 3 different types of ground configurations were used for comparison. Using a split power plane and full ground plane provides the best performance in terms of EM radiation from a PCB design approach.