Derate tantalum capacitors by how much? | Ask an FAE

Derate tantalum capacitors by how much? | Ask An FAE #3

Tuesday, January 24th, 2017

Let’s demystify the confusing topic of voltage derating (for Tantalum or Polymer capacitors.) Capacitors with a tantalum pentoxide dielectric offer pack a lot of capacitance into a tiny package while at the same providing a very low ESR. These capacitors are sometimes subject to faults introduced during a customer’s board manufacturing process. It is due to these faults that voltage derating is not only recommended but even required. James explains how to avoid failures by providing the proper amount of voltage derating, depending on the type of capacitor.

Episode Key Points

  • Tantalum voltage derating is related to power-on failure and not (necessarily) “failures in time”
  • Dielectric fault sites introduced during board reflow solering, is main reason for voltage derating
  • Polymer and MnO2 tantalum capacitors have different recommended derating
  • Look in the datasheet for recommended derating Information

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