摘要
A 12 Gbit/s limiting amplifier for fiber-optic transmission system is realized in a 2μm GaAs HBT technology. The whole circuit consists of an input buffer, three similar amplifier cells, an output buffer for driving 50 ft transmission lines and a pair of feedback networks for offset cancellation. At a positive supply voltage of 2 V and a negative supply voltage of - 2V, the power dissipation is about 280 mW. The small-signal gain is higher than 46 dB and the input dynamic range is about 40 dB with a constant single-ended output voltage swing of 400 mV. Satisfactory eye-diagrams are obtained at the bit rate of 12 Gbit/s limited by the test set-up. The chip area is 1.15 mm ×0.7 mm.
用2μmGaAs HBT工艺实现了12 Gbit/s用于光纤传输系统的限幅放大器.整个系统包括一级输入缓冲、三级放大、一级用于驱动50Ω传输线的输出缓冲和失调电压补偿回路4个部分.采用双电源供电,正电源为2V,负电源为-2V,功耗为280mW.小信号增益大于46dB,输入信号比特率为12 Gbit/s时,在输出电压幅度保持恒定(单端峰峰值400 mV)的条件下,输入动态范围约为40dB。眼图性能良好.芯片面积为1.15mm×0.7 mm.
