A 10 Gbps 4-PAM CMOS serial link transmitter with pre-emphasis

Abstract

This thesis presents the design of 10 Gbps 4-PAM CMOS serial link transmitters. A new area-power efficient fully differential CMOS current-mode serial link transmitter with a proposed 2/4-PAM signaling configuration and a new pre-emphasis scheme is presented. The pre-emphasis inthe analog domain and the use of de-emphasis approach decres pre-emphasis power and chip area. The high-speed operation of the transmitter is achieved from the small voltage swing of critical nodes of the transmitter, shunt peaking with active inductors, multiplexing-at-input approach, the distributed multiplexing nodes, and the low characteristic impedance of the channels. The fully differential and bidirectional current-mode signaling minimizes the noise injected to the power and ground rails and the electromagnetic interference exerted from the channels to neighboring devices. A PLL containing a proposed five-stage VCO is implemented to generate multi-phase on -chip clocks. The proposed VCO minimized the phase noise by keeping a constant rising and falling time. Simulation results demonstrate that the current received at the far end of a 10 cm FR-4 microstriop has a 4-PAM current eye width of 185 ps and eye hight of 1.21 mA. It consumes 57.6 mW power with differnetial delay block, or 19.2 mW power with inverter buffer chain. The total transistor area of the transmitter is 26.845 ....excluding the delay block.