Connect
the CLKINP SMA connector to a high-quality signal source such as an SMA100B signal
generator. Set the output power of the signal generator to 10dBm. Both CLKIN inputs are
terminated internally with 50Ω to AC-GND (that is, GND connection is formed by an
internal capacitor), so no external termination is required. Input can be driven
differentially, connect both CLKINP and CLKINN SMA connectors to a balun or a
differential clock source.
The default EVM profile configures the device in buffer
mode. The input frequency can be modified per the operating range of each functional
element if desired. This EVM setup guide and related plots assume 3200MHz input at CLKIN
for buffer mode.
To evaluate SYSREF repeater mode, connect the SYSREF input
SMAs to a differential output source such as an arbitrary function generator. The EVM
connections for the SYSREF input are DC-coupled and provide internal 100Ω termination.
In DC-coupled mode, the common mode bias on the SYSREFREQ pins must be between 1V and
2V. The input common mode requirements can be fulfilled with a standard LVDS output
buffer.
For evaluating SYNC mode and SYSREF windowing, to have a
SYSREFREQ input source capable of consistently meeting setup and hold requirements for a
single cycle of the input clock is critical. This can become very challenging at higher
frequencies where set up and hold requirements can be < 50ps. Another device capable
of picosecond-precision timed pulses, such as LMX2820 or LMX2594, can be used as a
reference input to both CLKIN and SYSREF for evaluating these features.