Work out jitter budget (serdes) instantly with clear inputs, formula shown and shareable results.
Total jitter combines deterministic jitter directly with random jitter scaled by a BER-dependent factor: TJ = DJ + Q x RJ, where Q is about 14 for 1e-12. Random jitter is Gaussian and unbounded, so tightening the BER target costs more eye even with no change in the hardware.
Jitter budget
TJ(pp) = DJ(pp) + Q(BER) x RJ(rms), Q = 14.07 at 1e-12 and 15.9 at 1e-16
Random jitter has no bound, so the observed peak-to-peak grows with the number of bits observed. A stricter BER samples further into the Gaussian tails.
Better reference clocks and PLL design for random jitter; equalisation, crosstalk control and supply noise reduction for deterministic jitter.