A 2-Gbaud 0.7-V swing voltage-mode driver and on-chip terminator for high-speed NRZ data transmission

Abstract

A large-swing, voltage-mode driver and an on-chip termination circuit are presented for high-speed nonreturn-to-zero (NRZ) data transmission through a copper cable. The proposed driver with active pull-up and pull-down can generate a 700-mV signal to deliver a 2 Gbaud serial NRZ data stream. Low output impedance offered by simple negative-feedback resistors alleviates the detrimental effect of the parasitic capacitance by supplying fast current impulses. A proposed on-chip termination circuit provides termination impedance to a mid-supply termination voltage with the benefit of reduced parasitic capacitance and better termination characteristics compared with off-chip termination. The driver and termination circuits have been incorporated in a 2 Gbaud transceiver chip and fabricated in 0.35 /spl mu/m CMOS technology. Measurements show a 1.4 V differential swing with a slew rate of 2.5 V/ns at the receiver output and a 65% reduction of reflection by the on-chip termination circuit with power consumption of 191 mW at 3.3 V supply.