Comparing with MLT-3 encoding scheme, the minimum distance between two levels of PAM-5 is only half that of MLT-3.This is equivalent to a loss of 6dB noise margin.

• PAM-5 编码跟100BASE-TX 所用的MLT-3编码相比，相邻电平之间的间距减小了一半，等效于损失了6dB的信噪比。