Title :
Pulse-width modulation pre-emphasis applied in a wireline transmitter, achieving 33 dB loss compensation at 5-Gb/s in 0.13-μm CMOS
Author :
Schrader, Jan-Rutger ; Klumperink, Eric A M ; Visschers, Jan L. ; Nauta, Bram
Author_Institution :
IC Design Group, Twente Univ., Enschede, Netherlands
fDate :
4/1/2006 12:00:00 AM
Abstract :
A transmitter pre-emphasis technique for copper cable equalization is presented that is based on pulse-width modulation (PWM). This technique is an alternative to the usual 2-tap symbol-spaced FIR (SSF) pre-emphasis. The technique uses timing resolution instead of amplitude resolution to adjust the filter transfer function, and therefore fits well with future high-speed low-voltage CMOS processes. Spectral analysis and time domain simulations illustrate that PWM pre-emphasis offers more relative high frequency boost than 2-tap SSF. Only one coefficient needs to be set to fit the equalizer transfer function to the channel, which makes convergence of an algorithm for automatic adaptation straightforward. A proof-of-concept 0.13-μm CMOS transmitter achieves in excess of 5 Gb/s (2-PAM) over 25 m of standard RG-58U low-end coaxial copper cable with 33 dB of channel loss at the Nyquist frequency (2.5 GHz). Measured BER at this speed and channel loss is <10-12.
Keywords :
CMOS integrated circuits; coaxial cables; equalisers; pulse width modulation; spectral analysis; time-domain analysis; transfer functions; transmitters; 0.13 micron; 2.5 GHz; 33 dB; 5 Gbit/s; CMOS integrated circuits; CMOS processes; CMOS transmitter; Nyquist frequency; PWM pre-emphasis; channel loss; coaxial copper cable; copper cable equalization; equalizer transfer function; filter transfer function; loss compensation; pulse-width modulation; spectral analysis; symbol-spaced FIR pre-emphasis; time domain simulations; timing resolution; transmitter pre-emphasis technique; wireline transmitter; Coaxial cables; Copper; Finite impulse response filter; Frequency; Propagation losses; Pulse modulation; Pulse width modulation; Space vector pulse width modulation; Transfer functions; Transmitters; CMOS integrated circuits; copper; equalizers; pulse-width modulation; transceivers; transmit pre-emphasis; transmit pre-shaping; wire communication;
Journal_Title :
Solid-State Circuits, IEEE Journal of
DOI :
10.1109/JSSC.2006.870897