Question
I would like to know the definition of the broadband random jitter spec? We
have integrated random jitter spec and broadband random jitter spec in the
datasheet. In the random jitter spec, we give the integration bandwidth. Then
how about the broadband random jitter? How do we define this spec?
Answer
The Broadband jitter spec is a way of describing the amount of ADC SNR
degradation that occurs when this part is used in a ADC clock signal path. We
take clean clock signal and measure the SNR of one of our ADCs (for instance,
the AD6645). We then insert the ADCLK846 into the path, and see how much SNR we
lose. We then convert that to femtoseconds of jitter. It's common for us to use
an ADC that operates around 100 Msamples/sec.