Electrical Engineering & Electronics Design

Can you share your project for your reference?

Here a link for a small start: https://emcfastpass.com/rightfirsttime/

It's a big bone  to delve into........

Yes it is definitely not something you learn overnight. Thanks for the lead

Unfortunately not really. It’s a product under active development by my company. That’s partly why my question was intentionally vague. I’m interested in learning whatever I can about the art of PCB design because I’m not even sure what questions to ask yet...

Steve

Hi, Best wishes for your new role.

I would suggest you to use basically make a modular pcb, every component separately connected by wires obviously after you try it on a breadboard.

You might not understand many unfavorable situations but you will learn it by trial and error.

Keep trying.

Hello Steve,

EMI/EMC compliance can vary widely depending what sector you are designing for such as from toys, automotive, medical etc... There are also many EMI/EMC testing areas, regulatory EMI/EMC compliance, manufacturer EMI/EMC compliance specification, customer requested specification EMI/EMC compliance and or geographical location EMI/EMC compliance. There are so many methods to reduce noise from a circuit and a quite limited number to prevent noise entering a circuit such as shielding. EMI/EMC compliance is usually sector specific.

Regards Jason

Jason,

This particular product will fall under applicable automotive standards for North America for initial product launch but the ultimate goal is the international mass transit space (bus, train, subway, light rail, etc.).

I know everybody has their own requirements for noise and immunity etc., so I am really just looking for reading material, and opportunities for self education.

Thanks for the input.

Steve

EMC starts with the understanding of Electro-Magnetics. The foremost authority on the subject is Henry Ott and his book is called "Electro-Magetic Compatability Engineering". It dives into every nuance of the subject matter for EMI / ESD / EM for EM compliance (EMC). Another good reference primer is by Tim Williams "EMC for Product Designers" and explains the process for EMC certification, but not how to solve tough EMC (electro-magnetic engineering) problems; for that you will need the Henry Ott book.

The standard to which all EMC is typically revolves around is MIL-STD-461 and DO-160 has sections which are diluted versions of it.

The medical community uses IEC 60601-1-2 which is now in the 4th edition and has made E-M Compliance (EMC) mandatory.

Consumer and industrial are really just FCC Part 15 class A (consumer and harder) and FCC Part 15 class B (industrial and easier), but that is for North America only !

Automotive uses SAE J551 (vehicle) and SAE J1113 (component), but Europe uses EMC Directives (95/54/EC), and radiated emissions are more stringent than FCC Part 15 class B (somewhat similar to MIL-STD-461).

The first key point is FREQUENCY and reducing UNINTENTIONAL emissions to a level that you are neither broadcasting or interfering with other equipment. Anything that is switching are the usual suspects.

The second key to most EMC is INDUCTANCE, so either eliminating or reducing inductance will be help reduce your emissions on those.

The third part is SHIELDING those signals that cannot be reduced.

SHIELDING and GROUNDING is vital to reducing inductance, but organizational placement of parts to localize electronics can be helpful as well.

If you fail and need professional help, I recommend checking the Interference Technology website for professionals and labs local to you (https://interferencetechnology.com/)

Also if your frequencies are well above 1 GHz (or even 100 MHz), then they are likely to also be a Signal Integrity (SI) problem. This is where Howard Johnson and the Art of Black Magic books come into play.

Unfortunately EMC, SI and Power integrity (PI) are all closely tied together with overlaps, so a power conversion problem may cause an EMC problem, or a SI problem may also cause an EMC problem (and vice-versa).

Thanks Steven. Very informative.

For most of our intended market we will fall under FCC part 15 class B. I am planning to take a "regional" approach to the board layout as best I can to ensure efficient power distribution to all components "post harness" since effectively all power in a vehicle is incredibly dirty.

I appreciate the book references and I will add them to my list.

Regards,

Steve