TVS diode recommendation

[Kampino]

Hi,

I´m looking for the right parameters to select a good TVS diode for the SWD pins of an nRF53-based circuit. The processor is powered by 1.8 V, so according to the datasheet, the maximum IO voltage is 2.1 V. For this I have selected one of those diodes:

https://www.mouser.de/c/circuit-protection/esd-suppressors-tvs-diodes/?working%20voltage=1.8%20V

Do they fit or can I use a higher voltage?

[ketiljo]

There are internal ESD protection diodes in the device already. So what you need is an external diode that improves the ESD protection the device already have. A 5 V diode is more than adequate for this. The internal diode will handle the overvoltage until the level is high enough for the external diode to "take over".

[Kampino]

Thank you