Whitepaper

An EMC/EMI system-design and testing methodology for FPD-Link III SerDes

Published by Texas Instruments

This article from Texas Instruments presents a systematic approach to EMC/EMI design and testing for automotive high-speed serializer/deserializer (SerDes) systems using FPD-Link III. It covers the CISPR 25 testing framework, where radiated emissions are measured across frequency bands using spectrum analyzers and LISNs in isolated chambers. The paper provides a step-by-step methodology for identifying noise sources by selectively enabling and disabling system components — including the imager, serializer, deserializer, and reference clock. A detailed design checklist follows, covering PCB stack-up recommendations (minimum four layers with solid ground planes), differential high-speed trace routing (100 Ω impedance, minimized skew and stubs), power and grounding best practices (multiple decoupling capacitors, ferrite beads, minimized current loops), and connector shielding guidance. The article serves as a practical reference for engineers designing automotive camera and video systems that must pass emissions testing.