LimeSDR Mini - DC protection on RX/TX ports?

#1

Hi,

I’d like to ask if the LimeSDR Mini would survive if I connect a signal line with +5v from a Bias-T to the TX or RX ports or do I need to put DC Blocks before the LimeSDR?

Thanks

#2

Bump

#3

@Zack, thoughts on this?

#4

My thoughts would be, that +5V DC could cause an AC transient on power on/off or connection/disconnection of up to +27dBm. And since that is higher than the recommended maximum of +12dBm (for RX) by about 32 times the power level, I would probably add a 15dB attenuator (or higher) to mitigate any risk of damage.

#5

Can someone tell me what the correct circuit should be for protecting the port from the DC component.
I apparently burned one LNA_L port through the MiniWheep + Bias-T injector to 12V, although there was a DC Block by 100nf capacitor there, but apparently it turned out to be a lot so that when turning on / off there was enough current to damage the input.