I have a product that has been FCC verified as an unintentional radiator, I have fixed a problem with the power that required a DC to DC converter that operates in the 100kHz to 300kHz range (added to the product). Would I need to get re-certified? Why or why not? Can you provide an requirement from the FCC?

I have my opinion and so does my supervisor, and we are not on the same page, so I will need concrete evidence to support one way or the other.

  • \$\begingroup\$ Did the DC/DC converter replace anything (e.g. a similar one, or a linear one)? \$\endgroup\$
    – Jack B
    Sep 19, 2019 at 21:23
  • \$\begingroup\$ It will be added. \$\endgroup\$
    – Voltage Spike
    Sep 19, 2019 at 21:51
  • \$\begingroup\$ Didn't you mean to say you have a product that was FCC certified as NOT an unintentional radiator? Because I can't see how the FCC would certify exactly the thing they are trying to prevent reaching the market \$\endgroup\$
    – fceconel
    Sep 19, 2019 at 22:24
  • 1
    \$\begingroup\$ I guess the proper terminology would be verified, it's passed the unintentional radiators test. \$\endgroup\$
    – Voltage Spike
    Sep 19, 2019 at 22:28
  • \$\begingroup\$ Regarding EMC: by definition: if A is EMC and B is EMC then that does not imply A+B is EMC. So if B was EMC and A (the DC/DC) was not EMC, and you replace A by a DC/DC that is EMC, you still have not proven the whole product is EMC. I'm unfamiliar with FCC, but for the European market, you HAVE to prove and therefore test the whole product again. \$\endgroup\$
    – Huisman
    Sep 20, 2019 at 5:35

1 Answer 1


First of all you have to re-verify your product to check if it has higher EMI emissions or not. If not, no re-certification is necessary provided you comply with the required documentation for such verification (Section 2.1043). Otherwise, if the DC/DC converter is incorporated in the circuit of the original product, you have to re-certify.

If the DC/DC converter is a separated box and connects to the power source and your product through wires with connectors) either it is already certified by its manufacturer, or you have to certify it yourself, apart from the already certified product.



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