DJ is jitter that is predictable and reproducable with specific causes. Together with Random jitter (RJ), it combines to give the Total jitter (TJ), usually of interest in data communcations applications. DJ is bounded and thus not Gaussian in nature. DJ tends to grow by fixed amounts, and can be caused by the length of trace on a PCB that 'rings' or causes reflections and crosstalk/EMI. Duty cycle distortion (DCD) and power supply noise are other possible contributors to DJ.
The equation for Total jitter is as follows:
TJ = DJ (pk-pk) + RJ(rms) * 2 * n,
where "n" is based on the bit error rate (BER) of the communcation link.