Hi Logic Team,
I know the impedance of the output of CMOS drivers vary, among other things, with voltage and whether the output is high or low. I am planning to series terminate the output of the driver to match the impedance of a 50 Ohm trace. If I am operating at 3.3 V, could you recommend a value of resistor to use, where the sum of the resistor and the driver output impedance would approximately equal 50 Ohms?
Also, in the datasheet there is a figure with a recommended PCB layout. In this figure the direction line has a pullup resistor. What is the purpose of the resistor?
Thank you,
HSG
