Diotec Semiconductor AG

TVS diodes are qualified using standardized surge waveforms that simulate different transient events. Two of the most common are the 8/20 µs current waveform and the 10/1000 µs pulse waveform. Although both describe surge conditions, they represent fundamentally different energy profiles and cannot be compared directly.

The impact on device ratings can be significant. A TVS diode may appear to offer several times higher surge capability simply because it was characterized using a different test waveform. In documented comparisons, the same device has shown a peak power rating that differed by almost a factor of six depending on whether the 8/20 µs or the 10/1000 µs standard was applied.

For design engineers, this distinction is critical. Selecting a protection device based solely on the headline wattage without considering the underlying test method can result in a substantially smaller safety margin than expected under real operating conditions.

At Diotec, surge ratings are always specified together with the corresponding test waveform to provide transparent and meaningful performance data. For example, the 5.0SMCJ series is rated at 5000 W under the 10/1000 µs waveform, making it well suited for protecting AC mains interfaces and DC supply rails against high-energy transient events.

For engineers specifying surge protection components, the key takeaway is straightforward: a peak pulse power rating is only meaningful when viewed together with the waveform used to determine it. Comparing ratings without this context can lead to incorrect assumptions and suboptimal component selection.

Accurate interpretation of surge specifications helps ensure that the selected TVS diode delivers the required protection performance under the actual transient conditions encountered in the application.