ESD protection of RF connector

[kruskal]

Lately I've been working on a DAB receiver project, and I've used the Si4684 receiver IC from Silicon Labs. In the schematics and layout guide for the chip, http://www.silabs.com/documents/public/application-notes/AN851.pdf, I came across some ESD protection circuitry that I don't really understand. Why would one connect both VN and VP to ground? For my home project I'm not going to have any ESD protection, but I'm just curious why it is done like this.

 

[davenn]

Why would one connect both VN and VP to ground?

so that either 1/2 cycle of a cyclic voltage will be grounded

 

[Harald Kapp]

For my home project I'm not going to have any ESD protection

I recommend you add one, then. Even if an ESD event doesn't produce immediately noticeable damage, internal chip structures may be damaged such that the device (receiver) experiences an early death.

You may also venture to use a half-wave stub which is short-circuited to ground at the end. This stub will present a nominal impedance at the wavelength it is designed for (1/2*lambda), but a short circuit to lower frequencies and DC. This is not so easy to design as you'll have to create a stripline or microstrip with a well defined impedance on your PCB, On the other hand: you'll have to do that for the signal path anyway,

 

[kruskal]

Thank you for your answers, I will consider adding some protection then