Datasheet

- 27 -

2.6.4 External Clock Source

It is also possible to apply a high-quality external signal source to the clock input rather than

using the on-board LMX2531 clock synthesizer. This will help quantify the LMX2531's

performance in an ultra-high-speed signal-path such as this one. When connecting an external

clock source, the generator amplitude should be set to 0dBm. Experiment with the clock signal

strength to determine what effect this has on the channel performance. Care should be taken to

not exceed +4 dBm at the clock input, to avoid damage to the ADC.

The external clock source is enabled through the register control panel in the software after

applying the signal generator to the Clock input SMA.

The external clock source should be disconnected or turned off when the on-board clock

source is selected. Failure to do so will result in poor performance due to the mixing of

the on-board clock and the small amount of external clock signal leaking through the

clock selection relay.

It is important to keep in mind that if the ADC's operating conditions are changed in any

significant way, especially temperature, the ADC should be calibrated again before proceeding.

Please refer to the WaveVision 5 Users' Guide and integral Help feature for more information

concerning the software.