I need to connect my BB signal which has 100KHz frequency from FPGA board to signal generator at the EXT INPUT port, but i found the signal on FPGA board disappeared when the BNC cable is connected,and if i pull off the connector from signal generator, the BB signal is correct.
I think the issue is due to the unmatching between FPGA IO port and 50 Ohm signal generator. How to reslove it, thank you !
This is not mtaching/unmatching issue...
Your board can not drive 50 Ohm because of it's high output impedance.You should use a simple buffer amplifier for instance an OpAmp buffer etc..
This is not mtaching/unmatching issue...
Your board can not drive 50 Ohm because of it's high output impedance.You should use a simple buffer amplifier for instance an OpAmp buffer etc..
No, if the signal level is not very critical you may use series resistor solution proposed by volker but if there is a constraint on voltage level, you should absolutely buffer amplifier that can also be implemented on even on breadboard because of low frequency just to test it.