74G clock buffer
I measured the 1:4 and 1:10 clock buffers and noticed a change in
edge speeds. The 1:4 measured at 256psec and 272psec rise/fall.
(This compares with 204psec rise and 284ps fall for the 1:2 buffer).
The average is slightly slower, but the edges are more symmetrical.
I expected the 1:4 might be slightly slower due to the larger fan
out internal to the buffer than for the 1:2. However, I expected
that since the
1:2 package heavily favors the GND return path, that the fall time
would be much faster than the rise time, contrary to the
measurements.
The 1:10 measured at 272ps rise and 264ps fall, slightly slower
still, but very symmetrical edges.
Thank you,
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Drive 50 Ohm load
Drive 50 Ohm load