Hello All, I have two PCBs, board A and board B. Board A has a 50MHz Crystal that I am making available through a high speed digital isolator (IL711-2E) to a chip that is on board B. Here's the datasheet on the isolator IC here. Now, I was thinking about using an SMA cable to go between the boards but given the high frequency, I'm thinking that it might be a good idea to treat the cable like a transmission line and properly terminate the ends. But I don't know much about matching the ends. I know that my isolator IC can source a maximum of 10mA at 5V and that the other end of the line will goto a CMOS digital input on the destination board. I spoke to a friend about this and he said that I should put a capacitor and termination resistor in parallel to ground with the CMOS input on board B, and that I should put a resistor in series with the isolator on the board A side. But I'm not sure what values to use for the resistor. Just from looking at the specs for the output drive of the isolator, it can source 10 mA @ 5V so should I assume that it's output impedance is 500 Ohms? If so, then should I use 500 Ohm resistors for the beginning and end resistors mentioned above? Any help greatly appreciated. Thanks, Jason O P.S. Forgot to mention but I don't expect the cable to be any longer than 6 feet.