Most ISI of interest (e.g; PCB trace loss) is low-pass in nature, so the DJ tends to have cycle-to-cycle components well in excess of PLL bandwidths.

The classic work by Lucky et. al shows that the term DJ is a misnomer since even simple deterministic channels need not develop a well-behaved jitter pdf. The set of zero crossings due to ISI is often fractal-like - it looks random and dense enough from far away, but when you zoom in there's a pattern of holes in the cheese. You wouldn't buy a ticket if some bands of numbers never get to win the lottery.

To paraphrase Orwell in Animal Farm, all data patterns are equal but some patterns are more equal than others. An extreme example of this behavior would be a 'killer pattern' that causes jitter well in excess of the so-called deterministic peak-peak value. This is why DJ is more insidious than RJ.

M.G.Rajan
www.eecalc.com