The most conservative method for routing the ECL signals

to multiple loads is to use the F100115 Quad Low Skew

Driver This device takes a differential ECL signal and out-

puts four of the same differential signals with a skew be-

tween them of less than 75 ps Two of these devices will

allow the CDD device to drive four PLAYER devices This

setup allows the ECL signals to be routed in a point to point

configuration to each PLAYER device

As with any high speed signal the routing of the signal must

be carefully done Sharp corners and other changes in trace

impedance should be avoided to reduce reflections in high

speed signal traces Traces longer then one inch should

have a series or parallel termination scheme Further sys-

tem considerations can be found in National’s F100K De-

sign Guide If these methods are followed the DP83241 sig-

nals will be able to drive multiple DP8325155 PLAYER de-

vices without any problems

TLF10385 – 13

FIGURE 5-8 Proper Bus Line Termination and Connections

TLF10385 – 14

Parallel Termination

FIGURE 5-9 CDD Device Driving Four PLAYER Devices Using Two F100115 Quad Low Skew Drivers

15