A 4Gbps 3-bit parallel transmitter with the crosstalk-induced jitter compensation using TX data timing control

By using the data timing control at transmitter (TX) side, the crosstalk-induced jitter (CIJ) is compensated in a 4 Gbps single-ended transmitter with 3-bit parallel data. CIJ is induced by the propagation velocity difference between the signal modes of parallel transmission lines. This velocity difference was compensated for by sending data early or late at TX according to the signal modes, so that the signals of different modes arrive at receiver at the same time. The proposed TX was implemented by using a 0.18 mum CMOS process. The parallel transmission lines used in the measurements are 4-inch long, have the minimum-allowed spacing between transmission lines to maximize CIJ. CIJ was measured to be reduced by about 50% from 53 ps to 27 ps at 4 Gbps excluding the random jitter component of 72 ps added at the TX side. The scheme used in this work can be expanded to more than three transmission lines.