User manual

Digital Interface Tester
4-119
AM700 Audio Measurement Set User Manual
Digital Jitter Measurement
If several pieces of equipment are cascaded, jitter may accumulate. An input
interface at the end of the chain will be required to correctly decode a signal with
much more jitter than each earlier stage would produce when operating alone. There
are many experiences of end users coming across problems related to this jitter
build-up. These problems can occur despite all the equipment involved apparently
conforming fully to the present interface standards.
A probable test is to apply defined levels of jitter to serial output and use the Jitter
Spectrum display to see how well the device being tested handles the jittered signal.
Set the AM700 generator for the amplitude and frequency of the jitter to apply to
the test digital signal. A jitter frequency of 20000 Hz is shown in Figure 4-65.
Figure 4-65: Jitter Spectrum display