Yes, I'm using discrete IC's and the same series. In my project I have to provide clock to two 2^7-1 PRBS with single clock source. As a clock driver I'm using insemi's NB100LVEP221. the output of two PRBS are fed to MUX to get a 1.25 Gbps output rate.
For clock I"m using onsemi's NBXSBA024 crystal Oscillator.
Actually I'm new to PCB designing so not able to decide how to proceed.
Pins of IC which are not of use should be left open or should be connected to ground??
I need help to complete the project on time..
NC pins can be left open. FR-4 laminate is sufficient for 2.5Gbps. Use as much differential transmission lines as possible. Make a careful (on paper) design of all setup and hold times, and delays for the clock distribution circuit.
Your plan is to mux two 1.25Gbps PRBS' into one 2.5Gbps. Why not using ONSemi's 10Gbps logic and go straight to the full-clock topology (clock=2.5GHz)?
In addition, try to use devices that have termination resistors in the chips. Making termination with 0805/0603 resistors is quite unfortunate, but necessary. Probably 4-layer PCB will be a must.