What is performance criterion A/B/C/D in EMI tests?

When doing EMI immunity tests, you will often encounter specifications that your device should e.g. “meet Performance Criterion B during the ESD test”.

The performance criteria, as defined in the IEC 61000 series of standards, e.g. IEC 61000-4-5:2014(surge test standard) are:

Additionally note that your device must notbecome dangerous under any circumstances, even if destroyed as per Performance Criterion D.

What defines a malfunction is up to the manufacturer of the device, but usually it’s related to whatever function it is advertised to perform. The manufacturer should define

Example: 230V LED bulb

As a manufacturer you could define e.g.

and so on. In all but the most demanding applications, manufacturers define the criteria conservativelyin order to increase the likelihood of passing the test. Since EMI laboratory tests are expensive, it’s in your best interest as a manufacturer not to over-define the criteria.