There are two options for the clock
reference input:
- The first and preferred option is
an external clock reference. The external clock reference allows connection to
the desired target clock of the final design and also minimizes the potential
effect of the clock reference during characterization of the clock signal path
performance. For the tests in this document, an oscillator (100 MHz) from Wenzel
is used as a very low phase noise clock source.
- The second option is to use an
onboard clock reference from an industrial grade oscillator. This design uses
the programmable clock generator LMK61E2. This device helps with evaluating the
sub-system without need of extensive test equipment. LMK61E2 is intended for
testing purposes only and has no defined radiation performance.