EMF from voltage regulators


I am building a project and will be using a 5v, 9A (#2866) and a variable step-up/down regulator (#2573). The most logical place for them is within moderate proximity to a compass, about 100mm.

They’ll both be fed at 24v, with the variable regulator outputting 12v.

Is there any testing on the magnetic interference generated by these voltage regulators? Does this change, based on input voltage, output voltage or load?

Many thanks for your help.


We have not characterized how much EMI those regulators generate or how it might affect a compass. For reference, though, we use switching regulators on several of our robot control boards that also contain IMUs (some of which are not even 100 mm across) and we have not experienced any notable issues, although we generally do not calibrate our magnetometers to particularly accurate standards.

In general, I expect switching regulators to get noisier when they are working harder, so under heavy loads or when the input voltage gets close to the output for step-down regulators. The D24V90F5 and S18V20AHV regulators operate in a power save mode that reduces their switching speed when under light load, which can also change the frequency range the noise affects.


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Straight wires carrying DC currents of just a few Amperes generate magnetic fields that can easily deflect a magnetic compass needle at a distance, and will certainly affect a magnetometer.

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Thanks so much for the responses. I really appreciate the advice.