一种2.5Gb/s CMOS宽动态范围光接收机模拟前端电路

A 2.5Gb/s CMOS Optical Receiver Analog Front-End Circuit with Wide Dynamic Range

摘要:

基于55nm CMOS工艺,设计了一种具有宽动态范围的2.5Gb/s光接收机模拟前端电路。作为光接收机的输入级电路,为了获得低噪声和高灵敏度性能,跨阻放大器(TIA)基于三级反相器级联结构,同时采用双自动增益控制(DAGC)电路来扩大输入信号的动态范围。为了提高增益,引入后置放大器,包括电平转换电路和三级差分放大电路,同时利用电容简并的方法来进一步拓展带宽,最后进行缓冲器输出。测试结果表明,在误码率为10-12的情况下,光接收机的输入灵敏度为-26dBm,过载光功率为3dBm,动态范围达到29dBm。光接收机在3.3V供电电压下,电流功耗为36mA,整体芯片面积为1176μm×985μm。

Abstract:

A 2.5Gb/s optical receiver analog front-end circuit with wide dynamic range has been developed based on 55nm standard CMOS technology. As the input stage of the optical receiver, in order to achieve low noise and high sensitivity, the transimpedance amplifier (TIA) based on a three-cascaded inverting topology applies dual automatic gain controls (DAGC) to broaden the input dynamic range. In order to improve the gain, a post amplifier is introduced, which includes a level shifter and a three-stage differential amplifier. At the same time, the method of capacitance degeneration is adopted to further extend the bandwidth, and the final stage is the output buffer. Test results show that the input sensitivity of the optical receiver is -26dBm, the overload is 3dBm, and the dynamic range is up to 29dBm for a bit-error rate of 10-12. The whole receiver draws a total current dissipation of 36mA under 3.3V power supply. And the chip has an area of only 1176μm×985μm.