What's the definition for "Pulse" in IEC62368-1?
A pulse is not specifically defined in IEC 62368-1. However, as noted in the standard, it can either be a voltage or current waveform that has maximum peak value depending on the test and condition when it is measured (i.e., normal, abnormal or single fault). A pulse may last from a fraction of second up to a few seconds. It can also be single or repetitive with off periods in between. (For switch mode power supplies (SMPS), sometimes pulses are associated with what some call “hiccup” mode.) Compliance with different requirements in Clause 5 generally will depend on pulse durations and off periods.
Also, keep in mind too, the use of the term “pulse” in IEC 62368-1 parallels use of the same undefined term in the legacy standard, IEC 60950-1. Sub-clause 2.2 of IEC 60950-1, including Figs. 2E.1 and 2E.2 contains some graphical representations of what are considered pulses.