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Design guide 2013 Victor H Kee BASc P Eng vic ultratech-labs com http www ultratech-labs com Phone - Fax - EMC Product Design Guide Prepared by Victor H Kee P Eng VP Marketing Business Development Ultratech Group of labs Bristol Circle Oakville Ontario Ca

Victor H Kee BASc P Eng vic ultratech-labs com http www ultratech-labs com Phone - Fax - EMC Product Design Guide Prepared by Victor H Kee P Eng VP Marketing Business Development Ultratech Group of labs Bristol Circle Oakville Ontario Canada L H G Phone - Fax - EMC Design Guide ?Ultratech Group of Labs All rights reserved Issue Sep Page i CVictor H Kee BASc P Eng vic ultratech-labs com http www ultratech-labs com Phone - Fax - Table of Contents EMC COMPLIANCE BY DESIGN The Cost of Non-Compliance THE PCB PRINTED CIRCUIT BOARD Single or Multilayer Choosing the right logic family The Current Loop Reducing Current Loops Spread-spectrum clocking SST CLK Power Grids De-coupling Capacitor Values Matching the high speed clock lines Isolating PCB Areas Interface and Connector Ports Component Placement and Layout on the PCB PCB Plane Topography and edge e ?ects The PCB area under I O Connectors Filter Bypass Operational amplifers comparators and bu ?ers Hardening Reset lines ESD Countermeasures Watch Dog Timers Transient Protection The Power Supply Filtering of AC power line Suppressing ground loops Switch Mode Device Transients Transformer concerns Snubbers on Output Diodes DC output Common-mode Filter I O Cables and Connectors Internal Cables The Ethernet Port The Chassis Enclosure Grounding Preparing a sample for EMC tests FINDING A COST-EFFECTIVE SOLUTION TO NON-COMPLIANCE PCB Layout Cable Cables Cables Chassis Construction EMC Design Guide Summary EMC Design Guide ?Ultratech Group of Labs All rights reserved Issue Sep Page ii CVictor H Kee BASc P Eng vic ultratech-labs com http www ultratech-labs com Phone - Fax - EMC COMPLIANCE BY DESIGN EMC compliance can be approached in several ways The most common approach taken is to design the product for functionality and price and then to test the product to obtain ?nal product certi ?cation prior to the marketing of the product This approach is still the most common used and often results in band-aid and addon ?xes at the production stage to resolve emissions and immunity problems not taken into account in the initial product procurement speci ?cations In the majority of situations a product stands ready to ship pending the ?nal acquisition of the product certi ?cations The time spent in bringing a product into compliance after it has been designed and prototyped usually impacts the whole sales and marketing process and in some special cases has been known to put a company under Our most often made request when this happens is Bring the product into compliance without making any changes Sadly enough we live in the real world of cause and e ?ect and once the product has been ?nalized for production the noise suppression options available to us reduces substantially and even these can be quite costly to implement in mass production runs Statistically speaking about of the products we test for compliance need some degree of added suppression for emissions and or immunity Since the subject of noise suppression is not taught formally in most universities and colleges