An inductorless 2.5 Gbit/s preamplifier was designed for the application of optical receivers in passive optical network and fabricated in a 0.18 μm RF CMOS process.The preamplifer consisted of a transimpedance amplifier,a single-ended Ti differential ended amplifier and an output driver.The transimpedance amplifier was based on a three-stage push-pull inverter structure.The special configuration allows for high gain and low noise performance.Phantom zeros technique was analyzed and employed to improve the bandwidth and ensure the stability of the TIA.To achieve a wide dynamic range,an automatic gain control technique with self-adaptive function was proposed to keep the bandwidth constant and stabilize the feedback network.The results show that the optical sensitivity is-29 dB·m and the maximum input optical power is 2 dB.m for 2.5 Gbit/s operation with a bit error rate of 10-10.The dynamic range is 31 dB·m.The chip consumes about 30 mW from a single 1.8 V supply.The chip area is 1 × 0.7 mm2.%基于0.18 μm RF CMOS工艺设计一种应用于无源光网络光接收机的无电感型2.5 Gbit/s前置放大器.该前置放大器主要包括跨阻放大器、单端转差分运算放大器和输出级电路.跨阻放大器基于3级推挽反相器结构,具有高增益和低噪声的特点,提高前置放大器的灵敏度;分析零点补偿原理,设计位于反馈环路之中的虚零点,提高跨阻放大器的工作速率,增加稳定性.提出一种新的具有自适应功能的自动增益控制技术,使得跨阻放大器在不同光输入功率下保持带宽不变,环路稳定,具有宽动态范围特性.研究结果表明:在误码率为10-10,传输速率为2.5 Gbit/s时,该前置放大器的接收光灵敏度高达-29 dB·m,输入最大光功率为2 dB·m,动态范围达31 dB·m;在1.8 V的电源电压下,芯片功耗为30 mW,芯片总面积为1×0.7 mm2.
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