应用于高速信号传输系统的多路选择器

提出了一种能够传输高速信号的多路选择器,并为其设计了一种低失真、宽带模拟开关.所提出开关的栅源过驱动电压由nMOS和pMOS的开启电压之和决定,并能够确保输入变化时,开关的栅源电压与阈值电压之差(VGST)保持恒定,从而基本消除了体效应的影响.采用TSMC 0.18μm CMOS工艺,HSPICE仿真结果表明,输入信号在0.3～1.7V之间变化时,开关的VGST基本保持恒定,其-3dB带宽大于10GHz,当输入频率为1GHz时,其无杂散动态范围为67.11dB;开关的开启时间为2.98ns,关断时间为1.35ns,确保了多路选择器的break-before-make特性.该结构可应用于高速信号传输系统中.

Multiplexer Design Applied to High-Speed Signal Transmission

A multiplexer with a low-distortion high-bandwidth analog switch is presented. The gate-to-source voltage of the switch is set by the combined on-voltage of a pMOS and an nMOS,and the difference between its gate-source voltage and the threshold voltage (VGST) is guaranteed to be constant with input variation. Thus, the body effect is nearly canceled.Implemented in a TSMC 0.18μm CMOS process, results from HSPICE simulation show that the VGST is nearly constant with an input range from 0.3 to 1.7V,and the - 3dB bandwidth is larger than 10GHz;the SFDR (spurious free dynamicrange) of the output is 67.11dB with 1GHz input frequency;the turn-on time is 2. 98ns,and the turn-off time is 1.35ns,which indicates a break-before-make action of the multiplexer. The proposed structure can be applied to high speed signal transmission.