Skew definitions

Skew specifications are like any other AC
electrical specification. The measurements
are taken at certain conditions which may or,
more likely, may not match a specific
condition in a system application. However,
like other AC specifications the skew
specification is valuable as a “bench mark”
for estimating certain circuit characteristics.
Skew specifications are most valuable in
clock–driving applications and applications
where duty cycle characteristics are
important. Three specific skew specifications
are addressed in this note.
Typical test conditions under which the skews
may be tested are:
Test load: 50pF, 500W
All outputs switching
0°C, 25°C, 70°C
VCC = 4.5V, 5.0V, 5.5V
Input conditions—VIL = 0V to VIH = 3V
Only data paths are tested for skew
characteristics (AC measurements such as
MR to output are not specified).