This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

LMK1C1104: Is the output series resistor required if output impedance of the chip already matches the transmission line?

Part Number: LMK1C1104

My customer is looking at using the LMK1C1104 to drive some 100 MHz signals in a new design.  They would be powered at 1.8V.

The input will be LVCMOS, 1.8V, over a 50 ohm line.

The outputs will drive 50 ohm lines to LVCMOS inputs.


The datasheet is a little unclear …  on page 6 I see the output impedance is 60 ohms, but on page 10 I see  recommendation

to add a series resistor on the output to match the transmission line.  But they don’t really need this resistor because the output

already (approximately) matches the line it is driving, right?


Everything is operating at Vdd = 1.8v