EMI-Related Common-Mode Noise Analysis of CMOS and CML Drivers

With the rapid advancement of high-speed serial communication technology, the common-mode (CM) noise issue in the transmitter (Tx) output driver of Serializer/Deserializer (SERDES) systems becomes increasingly prominent. This paper proposes equivalent circuit models of a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$20 \text{Gb} / \mathrm{s} \text{CMOS}$</tex> driver and a 20 Gb/s Current Mode Logic (CML) driver, based on TSMC N65 technology. Simulation results demonstrate that the proposed method effectively enables the analysis of CM noise. Furthermore, this paper conducts the comparative analysis of CM noise characteristics in CMOS and CML drivers from multiple relevant factors. The results show that the CM noise performance of the CML driver is better than that of the CMOS driver.