一种具有共模反馈的低抖动LVDS驱动器
A Low Ringing LVDS Driver With Common-mode Feedback Circuit
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摘要: LVDS即低压差分信号,因其固有的优点在对信号完整性及共模特性要求较高的系统中得到了越来越广泛的应用.由于非理想传输线和焊盘寄生效应的影响,输出波形有抖动且共模电压无法稳定.设计的LVDS驱动器采用一种新型预加重技术,通过引入高频极点的方法降低输出抖动,输出较为平滑的波形;而且共模反馈可以稳定共模电压.在0.18 μm的工艺下,抖动减小70 mV,共模电压偏移小于0.46%.Abstract: LVDS (Low-voltage Differential Signaling) is more and more used in systems which require keeping signal integrity and stable common-mode voltage.Because of imperfect termination and pad parasitic effects, there are ringing on the output voltage and common-mode voltage is unstable.This circuit designed applies a new pre-emphasis circuit technology which brings in a high frequency pole to decrease ringing and keep the output waves smooth.Besides, common-mode feedback circuit can stabilize common-mode voltage.In 0.18 μm process, the ringing is reduced 70 mV and the offset of common-mode voltage is less than 0.46%.