一种高速SerDes接收端自适应判决反馈均衡器设计

High-Speed SerDes Receiver Adaptive Decision Feedback Equalizer

针对高速通信中背板信道非理想特性引入的码间串扰问题,提出了一种增益自适应判决反馈均衡器(DFE)设计方法。该方法采用半速率结构,可在提高码间抗串扰的同时适应高速传输要求。通过引入自适应反馈环路实现最小均方算法(S-SLMS),并根据码间串扰大小自动调整抽头系数以达到最佳均衡效果;采用动态比较器对数据进行采样,在完成正确采样的同时引入尽可能小的延迟。采用5.4 Gbps输入信号进行仿真,结果表明,该均衡器可对加扰的输入信号正确恢复数据,恢复出的眼图宽度为0.91UI,成功消除了2个后标分量,有效消除了码间串扰,DFE整体电路功耗仅17.8 mW。

In order to eliminate inter-code crosstalk caused by non-ideal characteristics of backplane channel during data transmission,a Decision Feedback Equalizer(DFE) with gain adaptive function is proposed in the paper.The whole DFE adopts half-rate structure to adapt to the requirements of high-speed transmission.An adaptive feedback loop is introduced to implement Single to Single Least Mean Square Algorithm(S-S LMS),and the tap coefficient is adjusted when the cross-talk size changes,to make the equalization effect better.A dynamic comparator is used to sample the data,introducing the smallest possible delay while completing the correct sampling.For the input signal of 5.4 Gbps,the simulation results show that the equalizer realizes the correct recovery of data,the recovered eye image width is 0.91 UI,and the two post-standard components are successfully eliminated.The DFE power dissipation is only 17.8 mW.