4-Gb/s Parallel Receivers With Adaptive Far-End Crosstalk Cancellation

Two 4-Gb/s parallel receivers with adaptive far-end crosstalk (FEXT) cancellation are presented. By using the highpass filter, the crosstalk cancellation (XTC) signal is generated to compensate the FEXT signal. A power detection loop is adopted to achieve automatic tuning of the XTC coefficient for different channel spacing. The receivers with adaptive XTC are fabricated in 40-nm CMOS technology, and the core area occupies 0.0229 mm². The maximum power consumption from a 1.2-V supply is 15.6 mW. For two 4-Gb/s pseudorandom binary sequences of 2⁷-1 passing through FR4 printed circuit board traces with 5-in length and 8-mil spacing, the measured peak-topeak jitter of the data is reduced by 32.22 ps by using the adaptive XTC. The measured adaptation time of the power detection loop is 63.44 μs.