EXFO PSO-100 Series Optical Sampling Oscilloscopes - Manual (Page 124)

Measurement Definitions
116 PSO-100
Duty Cycle Distortion
Duty Cycle Distortion
The duty cycle distortion (DCD) is a measurement of the time separation of
the rising and falling edge of the eye at the center (50 %) level. The DCD is
defined in percentage of the bit period as:
In a "perfect" eye with no timing- and amplitude jitter, and a 50 % crossing,
the DCD is zero.
DCD 100%
T
rise,center
T
fall,center
–
bit period
------------------------------------------------------ =
50 %
Bit period
DCD time