基于电流选择器预加重的CML驱动电路设计

Design of a pre-emphasis driving circuit using CML with current selectors

为提升基于PIN电学结构载流子注入式硅基电光调制器性能,采用TSMC 0.18μm CMOS工艺设计一种新型预加重驱动电路.该电路采用电流模逻辑(CML)结构,并引入低压差分信号(LVDS)型电流选择器,在实现提升响应速度和工作带宽的同时,降低整体平均功耗.仿真结果表明:基于PIN电学结构载流子注入式硅基电光调制器的电压响应时间同时受预加重驱动信号过冲幅度和持续时间影响.当预加重驱动信号过冲幅度和持续时间分别取值为2 V和0.2 ns时,基于PIN电学结构载流子注入式硅基电光调制器的电压响应时间缩减了16.7%,工作带宽扩展至4.34倍,且根据不同的开关活动性需求,平均功耗最高降低了60%.

In this paper, a new pre-emphasis driving circuit is designed with the 0.18 μm TSMC CMOS technique to improve the performance of PIN-diode-based silicon electro-optic modulator. The pre-emphasis circuit adopts the Current Mode Logic（CML） in which a Low Voltage Differential Signaling（LVDS） module is engineered to act as a current selector so as to achieve high-speed operation with broadband and low power consumption. The simulation results show that the electrical response time of PIN-diode-based silicon electro-optic modulator depends on the overshoot amplitude and overshoot duration of the pre-emphasis driving signal. When both values of an overshoot amplitude and an overshoot duration are set to be 2 V and 0.2 ns respectively and driven by the proposed pre-emphasis circuit, the electrical response time of PIN-diode-based silicon electro-optic modulator is reduced by 16.7%, and the operating bandwidth is nearly 4.34 times the intrinsic bandwidth. In addition, judged by the varying requirements for the switching activity, the average power consumption can be reduced by 60% at most.