Planar process vs. 3D chip

The clock is the fixed frequency signal that controls the logic circuitry on a chip. A clock cycle is the period (measured in seconds) of the clock. Thus a 5 GHz clock has a cycle time of 0.2 nanoseconds. In order for the circuitry on the chip to work properly, it is necessary (within certain limits depending on the actual chip design) for the clock signal to arrive at all points on the chip at nearly the same time. This is what it means for the chip to be in sync. The assumption you quoted makes the assumption that the delay across the chip cannot exceed 1/2 of the clock cycle. For a 5 GHz clock, this is 0.1 nanosecond. Since the speed of light is 300,000,000 meters second, the distance covered in 0.1 nanosecond. is 0.03 meters or 30 millimeters (mm). Slower clock speeds have larger cycle times and allow the chip to be larger and still achieve the 1/2 cycle requirement.

The datasheet I found show the LM8560 being a SDIP chip and not SOP. This means you need a SDIP to DIP adapter (sdip is a skinny dip which is thinner than dip, sop is a surface mount pkg which is thinner and shorter than dip).

I have used these guys before: http://www.epboard.com/eproducts/ezadapter.htm#Shrink%20DIP%20%28SDIP%29%20to%20DIP%20Adapter

They have a SDIP to DIP 28 pin adapter if that's what you require. They also do custom adapters where you can give them the specs and they make the adapter for you.