SMB6FxxA: what does the second value (4kW (8/20µs) in the line "peak pulse power" stand for? 4kW is far over the max. peak pulse power dissipation of 600W. Or is it a typo, and 4kV is meant (instead of 4kW)?

NHiel.1 · ‎2022-08-31

Peter BENSCH · ‎2022-08-31

Welcome, @NHiel.1, to the community!

The value is a pulse value, which is also only guaranteed at the said pulse values.

To be more precise, the 600W also only applies for a limited time, namely the 10/1000μs pulse mentioned in the data sheet, where 10µs refers to rise time tr and 1000µs to the pulse duration td. For the 4kW mentioned, this is tr=8μs and td=20µs.

The shorter the pulse, the higher the power the TVS can handle without thermal damage to the chip, as this may only happen with a very low duty cycle.

You will find more details in e.g. AN316.

Does it answer your question?

Regards

/Peter

In order to give better visibility on the answered topics, please click on Accept as Solution on the reply which solved your issue or answered your question.

View solution in original post

Peter BENSCH · ‎2022-08-31

Welcome, @NHiel.1, to the community!

The value is a pulse value, which is also only guaranteed at the said pulse values.

To be more precise, the 600W also only applies for a limited time, namely the 10/1000μs pulse mentioned in the data sheet, where 10µs refers to rise time tr and 1000µs to the pulse duration td. For the 4kW mentioned, this is tr=8μs and td=20µs.

The shorter the pulse, the higher the power the TVS can handle without thermal damage to the chip, as this may only happen with a very low duty cycle.

You will find more details in e.g. AN316.

Does it answer your question?

Regards

/Peter

In order to give better visibility on the answered topics, please click on Accept as Solution on the reply which solved your issue or answered your question.

NHiel.1 · ‎2022-08-31

Dear Peter,

many thanks for the explanation. I hadn´t found any explanantion for 10/1000µs or 8/20µs values. With knowing that first value is tr and second is td, the data make sense. And yes, the response answered our question. Many thanks again and best regads

Norbert

Peter BENSCH · ‎2022-08-31

You're welcome!

If the problem is resolved, please mark this thread as answered by selecting Select as best. This will help other users find that answer faster.

Regards

/Peter

In order to give better visibility on the answered topics, please click on Accept as Solution on the reply which solved your issue or answered your question.