"All the EMC problems really start at the PCB level. And then they can manifest at every level above that. Sometimes on the board, sometimes not until you’re looking at an entirely fully assembled electric vehicle city bus, which is one of the things I got to troubleshoot.
But fundamentally, there are certain things that are going to generate electromagnetic noise. And, I think everyone’s kind of aware that motors are going to generate noise. Things that have sparks, like it used to be one of the only things you worried about on a car was the spark igniters, right, from the fuel injection system interfering with the AM radio. That was like it.
Cars have gotten a lot more complicated since then. A lot more sophisticated. There’s a lot more stuff to go wrong. But one of the things that I think is less obvious to people is that any switching operation generates electromagnetic noise.
And that’s not, oh, sometimes it does that. That’s what happens when you have switching operations. Now that means DC to DC converters. So just because you have DC on one side and DC on the other, all the switching that happens to go from wall power to 12 volts or wall power to 5 volts or 5 volts to 3.3, that’s all generating electromagnetic noise at higher and higher frequencies.
Now that noise can be more severe, it can be less severe, but it’s always there. The other thing is every single digital electronic system fundamentally is switching voltages."
Watch Karen Burnham discuss EMC in aerospace and automotive in Trace Talks EP 4.