A 7.5-Gb/s One-Tap-FFE Transmitter With Adaptive Far-End Crosstalk Cancellation Using Duty Cycle Detection

• Published in: IEEE journal of solid-state circuits Vol. 48; no. 2; pp. 391 - 404
• Main Authors: KAO, Shih-Yuan, LIU, Shen-Iuan
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.02.2013; Institute of Electrical and Electronics Engineers
• Subjects: Adaptation coefficient; Applied sciences; Calibration; Circuit properties; Circuits of signal characteristics conditioning (including delay circuits); Clocks; Crosstalk; crosstalk-induced jitter (CIJ); Design. Technologies. Operation analysis. Testing; Detectors; Digital circuits; Electric, optical and optoelectronic circuits; Electronic circuits; Electronic equipment and fabrication. Passive components, printed wiring boards, connectics; Electronics; Exact sciences and technology; far-end crosstalk (FEXT) cancellation; feed-forward equalizer (FFE); Integrated circuits; intersymbol interference (ISI); Microstrip; parallel interface; Receivers; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; transmitter; Transmitters; intersymbol interference (ISI); Crosstalk; Coupled line; Transmitter; Jitter; Equalizer; Microstrip line; Adaptation coefficient; feed-forward equalizer (FFE); Transmission line; Complementary MOS technology; crosstalk-induced jitter (CIJ); Electric power consumption; far-end crosstalk (FEXT) cancellation; Feedforward; Root mean square value; Printed circuit board; Spacing; Calibration; Digital control; Interference suppression; Intersymbol interference; parallel interface; Line spacing; Printed circuit
• ISSN: 0018-9200; 1558-173X
• DOI: 10.1109/JSSC.2012.2227604

A 2.5-7.5-Gb/s transmitter with one-tap feed-forward equalizer (FFE) and adaptive far-end crosstalk (FEXT) cancellation is presented. To cancel the intersymbol interference, the one-tap FFE is also employed. A crosstalk canceller (XTC) is adapted to cancel FEXT by using inverse pulses. To cancel the FEXT due to the coupled microstrip lines with various spacing, the pulse amplitude of the XTC is digitally controlled by using the proposed duty cycle detection. The one-tap FFE and the XTC are merged together to save the power. This adaptive transmitter is fabricated in a 65-nm CMOS technology. The maximum power consumption from a 1.2-V supply is 26.4 mW, and the core area occupies 0.0307 mm 2 . For two 5-in FR4 printed-circuit-board traces with the spacing of 8 mil, the measured rms and peak-to-peak jitters of the recovered data are improved by 10.01 and 48.9 ps, respectively, for a 7.5-Gb/s PRBS of 2 7 -1 . The measured calibration time of the XTC is 1.17 μs.