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Visitor II
January 6, 2026
Question

About SMP100LC

  • January 6, 2026
  • 1 reply
  • 47 views

Hi Team,

 

It appears that the varistor turned on at a voltage lower than the value specified in the datasheet.

・​Detailed V-I characteristics of the varistor

・​How significant is the variation between individual varistors?

・Once a varistor turns on, does it remain on even after the power is turned off?

・What is the tolerance of VBO?​

・Does the failure mode of this varistor result in a short circuit?

Thanks

    This topic has been closed for replies.

    1 reply

    ST Employee
    January 6, 2026

    Hi,

    VBO specified on the datasheet is a maximum value, so it is normal to get a turn ON voltage lower than VBO specified on datasheet (note that VBO is measured according to figure 16 and 17 schematics). Turn ON voltage is between VR value and VBO value.

    Regarding SMP100LC turn OFF: once SMP100LC turns ON, the only way to turn it OFF is to reduce the current below IH value.

    SMP100LC typically fails in short-circuit when absolute maximum ratings are exceeded.

    Best regards.

    Fabrice.