Assume that I have some generic antenna connector, followed by a pi-filter/50ohm impedance matching components, then a DC blocking cap (as per the RF switch recommendations) and then a RF switch for split tx/rx semiduplex transceiver, as in this schematic:

How do I best protect this RF switch from ESD coming in from human fingers touching the antenna connector? I need the highest ESD class (4) of the IEC61000−4−2, meaning 8kV contact discharge, 15kV air discharge.

I'm considering a specialized "ultra-low capacitance" TVS diode such as ESD8472 (rated up to 20kV), which is bidirectional.

Questions:

• Is this TVS diode the way to go?
• If so, where do I place it in this schematic? Directly on the antenna or somewhere else?
• How to determine the suitable breakdown voltage? I'm assuming it should be based on the RF switch supply which is 3.3V.

posted almost 3 years ago

CC BY-SA 4.0

Lundin‭

1543 reputation 35 54 278 67