NRZ TIMING RECOVERY TECHNIQUE FOR BAND-LIMITED-CHANNELS

Nonreturn-to-zero (NRZ) data, when transmitted over band-limited chann els, suffer from the lack of zero crossings because the elongated tail of each pulse interferes with subsequent ones, causing intersymbol in terference (ISI), An NRZ timing recovery technique working with a deci sion-feedback equalizer (DFE) recovers the clock from the equalized wa veform and enables data transmission at a rate ten times higher than t he channel bandwidth, The proposed timing recovery technique uses a da ta-triggered low-jitter phase detector to sustain phase locking even w ith 600 missing transitions, A data rate of 30 Mb/s in 3-MHz bandwidth is demonstrated with a peak-peak clock jitter of 2 ns using 2-mu m CM OS.