1.25Gb/s CMOS高灵敏度宽动态范围跨阻放大器

A 1.25Gb/s CMOS Transimpedance Amplifier with High Sensitivity and Wide Dynamic Range

摘要:

采用0.35μm CMOS工艺设计并实现了一种新的应用于1.25Gb/s光纤通信接收机的高灵敏度、宽动态范围跨阻放大器电路。引入电流注入技术提高输入管跨导、优化噪声性能、提高灵敏度。自带直流反馈实现直流消除功能，同时采用自动增益控制机制，提高动态范围。仿真结果表明，该电路具有82.02dBΩ的跨阻增益、872.7MHz的带宽、23.74kHz的低频截止频率，输入等效噪声电流为4.08pA/Hz，最大输入光信号为+3dBm(2mA)，在3.3V的电源电压下，芯片功耗为43.4mW。

Abstract:

A novel transimpedance amplifier with high sensitivity and wide dynamic range for 1.25Gb/s optical communication receiver was designed and implemented in 0.35μm CMOS technology. The current injection technique, which enlarges the transconductance of the input transistor, is imposed to optimize the noise performance and improve the sensitivity. Besides the automatic gain control mechanism, the transimpedance amplifier employs internal DC-feedback for DC cancellation to achieve a wide dynamic range. The post-layout simulation results show the transimpedance gain is 82.02dBΩ, the bandwidth is 872.7MHz, the cutoff frequency is 23.74kHz, the input equivalent noise current is 4.08pA/Hz, the input overload current signal is about +3dBm(2mA) and the power consumption is 43.4mW under a 3.3V power supply.