Research And Design Of A 6.25Gb/s Adaptive Decision Feedback Equalizer In 0.18?m CMOS Technology

In recent years,with the cloud computing,video on demand and other large data throughput applications rise,the demands for data transmission rate are getting higher and higher.Nowadays,the serial communication technology has gradually replaced the traditional parallel communication technology to become the mainstream communication technology of high-speed data communication.However,non-ideal factors such as high frequency attenuation,crosstalk,echo loss and noise in channel can cause serious inter-symbol interference in the transmitted flows,which will seriously affect the quality and the highest rate of data transmission.Since adaptive decision feedback equalizer can deal with the inter-symbol interference caused by the non-ideal characteristics of channels,it has become the research hotspot.Based on the extensive research and in-depth study of the existing Decision Feedback Equalizer technology,this paper designs an adaptive Decision Feedback Equalizer in standard 0.18?m CMOS technology.The equalizer mainly includes a half rate Decision Feedback Equalizer circuit and a coefficient adaptive circuit.In order to achieve a higher operating rate,the half-rate Decision Feedback Equalizer of each module circuit using current-mode logic,including current mode adder,current mode Dflip-flop,current-mode multiplexer circuit;Coefficient adaptive circuit designs by using the Signal-Signal Least Mean Square algorithm,including error detector,6-bit up/down counter and 6-bit segmented current rudder digital-to-analog conversion circuit.The simulation results show that the equalizer designed at all process corners can work reliably at the data rate of 6.25Gb/s.Among them,the output data eye jitter is less than 6ps,swing minimum 400 mV,the maximum swing 700 mV,horizontal opening greater than 0.95 UI.The entire chip has a layout area of 0.68×0.71mm2.Compared with other similar designs,this design is compact.