A CMOS 1 Gb/s 5-Tap Fractionally-Spaced Equalizer
Hernandez-Garduno, D.; Silva-Martinez, J.
Solid-State Circuits, IEEE Journal of
Volume 43, Issue 11, Nov. 2008 Page(s):2482 - 2491
Digital Object Identifier 10.1109/JSSC.2008.2005536
Summary:This paper presents the design of a 1 Gb/s 5-tap T/2 fractionally-spaced equalizer. The T/2 delay lines are based on third-order linear-phase double terminated sections that offer a tunable group delay of 500 ps with less than 10% ripple and a 3 dB bandwidth greater than 600 MHz. Furthermore, the equalizer architecture introduces a broadband summing circuit using a transimpedance I/V converter that increases the bandwidth by a factor of 3.6 over a conventional resistive loaded analog adder. The topology's performance is demonstrated in the equalization of 1 Gb/s binary data through CAT5e twisted-pair cables for up to 23 meters. The vertical eye-opening increases from 0% to 58%. Implemented in CMOS 0.35 mum, the transversal equalizer occupies an area of 26 mm2 and consumes 32 mA.
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