RTK Express turns on when receiving DC voltage from external receiver via splitter

GPS/GNSS Development Boards
1

I am using an Alison Microwave AD325 splitter and when the RTK Express antenna feed is connected to one of the AD325 ports it turns on (assume the splitter has DC pass through, but need to check with supplier). Is this expected behavior? Is there a possibility of damaging the RTK Express if it is receiving DC voltage on the antenna connector?

2

Hi,

Oooh. Nasty. Please be extremely careful. If you are back-feeding power from another device to the Express’ antenna port, that voltage will be being fed back into the ZED-F9P V_RF and RF_IN pins and from there will probably find its way back to the 3.3V rail and - yes - power everything up.

If you’re back-feeding 3.3V, you’re unlikely to have done any permanent damage. But please disconnect immediately and find a way to block the DC. A higher voltage could easily cause damage…

I hope this helps,

Paul

3

Thanks Paul, at least that make sense now. I did not get much of an explanation from the supplier, so will have to do some testing on the bench with a meter and see what exactly is going on with the splitter.