4/2 PAM Pre-emphasis Transmitter with Combined Driver and Mux

A new multi-Gbps pre-emphasis design methodology and circuits for a 4/2 PAM transmitter over cable are proposed. Theoretical analysis of the total frequency response of pre-emphasis, package, cable and termination are carried out. Then, we propose a pre-emphasis design method so that the over all frequency response in the receiver side is uniform within the desired frequency range. A test chip of transmitter with pre-emphasis, PLL circuit and on-chip termination resistors are implemented to verify the design methodology. The measurement results of 10/5 Gbps (4/2 PAM) are carried out over 5 meter (m) long cable and is in agreement with our analysis and simulation results