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The line to ground voltage is 54 volts, and I would like to know if it is possible to have two bi-directional TVS diodes in series.

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I will be using TSPMF4L30A, and the reverse standoff voltage is 30V. If I were to put two of these TVS diodes in series, would I then have reverse standoff voltage of 60V, and would it clamp at 96.8V (48.4V + 48.4V)?

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Yes you can put two bi-directional TVS diodes in series. They also supply parts well over 600V.

Perhaps your uncertainty is due to choosing unidirectional symbols.


I just checked your part number. The TSPMF4L30A shud be TPSMF4L30A which is unidirectional (Zener) and not bi-directional.

Using them as you have shown is equivalent to using a single 400W unidirectional TVS with 60V Voltage - Reverse Standoff (Typ)

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    \$\begingroup\$ Thank you, I will get two bidirectional TVS diode. Is there a reason why you are mentioning about supply parts well over 600V? The main reason why I wanted to put two tvs diode in series is to reduce capacitance, and to make sure that using two bi-directional tvs diode will provide a standoff voltage of 60V. \$\endgroup\$ Nov 13, 2019 at 19:33
  • \$\begingroup\$ Keep in mind that the bane of a TVS is inductance. Putting two packages in series more than doubles the inductance (traces are inductors too). Also, keep them as close as possible to the connector you're protecting from and keep the cathode as close as possible to (if not on) the trace. There should be no path from the pin to the board that doesn't go through that pin, just like when you hire a security guard you put his desk right by the door. If you insist on using two diodes, put them as close as you can facing opposite directions to cancel the fields, and keep your ground path short. \$\endgroup\$ Nov 13, 2019 at 20:59
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    \$\begingroup\$ I will remember to do the following as you mentioned above. \$\endgroup\$ Nov 14, 2019 at 1:48
  • \$\begingroup\$ It looks like I will have to use a Uni-directional TPSMF4L30A. Thanks \$\endgroup\$ Nov 14, 2019 at 1:56

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