Tektronix TDS7054

Appendix B: Automatic Measurements Supported
CSA7000 Series, TDS7000 Series, & TDS6000 S eries Instruments User Manual
B-5
Table B- 1: Mask measurements and their definition (optional on TDS7000 Series & TDS6000 Series) (Cont.)
Name Defi nition
S/N Ratio Ratio of the signal amplitude to the noise of the top or base of the signal as specified
b
y
t
h
e
u
s
e
r
.
b
y
t
h
e
u
s
e
r
.
S/N Ratio = (PTop -- PBase)/(PTop
sigma
or PBase
sigma
)
DutyCycleDistortion The peak-to-peak time variation of the first eye crossing measured at t he MidRef as a
p
e
r
c
e
n
t
o
f
t
h
e
e
y
e
p
e
r
i
o
d
.
p
e
r
c
e
n
t
o
f
t
h
e
e
y
e
p
e
r
i
o
d
.
DCD (%) = 100% x TDCD
p--p
/(TCross2
mean
-- TCross1
mean
)
Quality Factor Ratio of eye size to noise.
y
y
Quality Factor = (PTop
m
e
an
-- PBase
m
e
an
)/(PTop
si
g
ma
+ PBase
si
g
ma
)
Levels Used in Taking Amplitude, Timing, and Area Measurements
Refer to Figure B--1 and the descriptions that follow to interpret the definitions
of waveforms in categories Amplitude, T iming, and Area. Low reference, mid
reference, and high reference are the default reference levels and are adjustable.
High (Histogram)
Low (Histogram)
Low (Min/Max)
High (Min/Max)
Mid reference
High reference
90%
10%
50%
Low reference
Figure B- 1: Levels used to determine measurements