A 2.5 Gbps transimpedance amplifier (TIA) with the feedback resistance self-adaptively adjusted is designed for the application of optical receivers in passive optical network and implemented in Global Foundries (GF) 0.18 μm CMOS standard process. The main structure of the circuit consists of an improved three-stage current multiplexing push-pull inverter. With the diode-connected-transistor placed at each end of the inverter, the extra pole will be pulled away in order to increase the stability of the loop system. The feedback resistance of TIA is connected in parallel with the NMOS transistor, and the gate voltage of the tube is adjusted automatically to control the resistance value of this parallel structure in order to overcome the defect of the inverter which will work in the linear region on the condition of excessive optical power. A low-dropout linear regulator (LDO) is adopted from the power supply to the TIA to isolate power supply noise. The measured results demonstrate that the fabricated TIA with a photodetector capacitance of 3.2 pF has a transimpedance gain of 41.64 dBΩ with a current signal frequency of 2.5 Gbit/s, and a −3 dB bandwidth of 2.35 GHz. The average input-referred noise current spectral density within the bandwidth is185 pA/Hz1/2, signal rise time is 195 ps, fall time is 227 ps, eye diagram height is 28 mV, optical sensitivity is −30.6 dBm, and power consumption is only 52 mW at 3.3 V power supply voltage, the chip area is 0.22 × 0.3 mm².

中文翻译：

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一种增益自适应调节的新型 2.5 Gbps 前置跨阻放大器

2.5 Gbps 跨阻放大器（TIA），反馈电阻自适应调节，专为光接收器在无源光网络中的应用而设计，在 Global Foundries (GF) 0.18 中实现 μm CMOS 标准工艺。电路的主要结构由改进的三级电流多路复用推挽逆变器组成。通过在逆变器的每一端放置二极管连接的晶体管，额外的极将被拉走，以增加环路系统的稳定性。TIA的反馈电阻与NMOS晶体管并联，管的栅极电压自动调节控制这种并联结构的电阻值，以克服逆变器工作在线性区的缺陷。光功率过大的情况。从电源到 TIA 采用低压差线性稳压器 (LDO) 隔离电源噪声。测量结果表明，制造的 TIA 的光电探测器电容为 3。Ω当前信号频率为 2.5 Gbit/s，-3 dB 带宽为 2.35 GHz。带宽内的平均输入参考噪声电流谱密度为 185 pA/Hz1/2，信号上升时间为195 ps，下降时间为227 ps，眼图高度为28 mV，光灵敏度为-30.6 dBm，3.3 V电源电压下功耗仅为52 mW，芯片面积为0.22 × 0.3 毫米²。