A 14-Gb/s 4-PAM Adaptive Analog Equalizer for 40-inch Backplane Interconnections

Limitations of frequency response in backplane interconnections impede high-speed data transmission beyond Gbps. A 14-Gb/s 4-PAM adaptive analog equalizer is proposed to compensate the 40-inch backplane interconnections by using a sum-feedback filter (SFF), relaxing the design requirement of the conventional analog feed-forward equalizers (FFE). 4-level pulse amplitude modulation (PAM) is also adopted to increase the transmission data rate over bandwidth-limited channel. The 4-PAM adaptive equalizer has been fabricated in a 0.18-mum CMOS technology, while dissipating 121 mW from a single 1.8-V power supply.