ATS9360 User Manual
31
Optional External Clock
ATS9360 PCI Express Digitizer optionally allows you to
supply the ADC clock. This option is extremely important in
many RF applications in which phase measurements must be
made between the inputs themselves or between the inputs
and an external event.
Another application that requires external clock is Optical
Coherence Tomography (OCT) that sometimes requires
analog sampling to take place relative to an MZI clock,
sometimes also known as k-clock.
Driving high performance ADCs must be done carefully, as
any injection of phase jitter through ADC clocks will result in
reduction in data conversion quality.
Aside from phase noise, the clock signal for a pipelined ADC
must also have a duty cycle close to 50%. This maximizes
the dynamic performance of the ADC. See Fast External
Clock section below for more details.
External clock input impedance is fixed at 50 Ohms.
External clock input is always AC-coupled.
There are two types of External Clock supported by
ATS9360:
Fast External Clock
10 MHz Clock Reference
The following paragraphs describe the two types of External
Clock input and outline the restrictions on each of them.
