12-Gb/s decision circuit IC using AlGaAs/GaAS HBT technology

Circuit technology that achieves a high-bit-rate decision circuit with high input sensitivity for application to future optical communication systems by using AlGaAs/GaAs heterojunction bipolar transistors (HBTs) is reviewed. This technology includes a highly accurate transistor model expressing the overshoot effect and a novel circuit configuration with a wideband preamplifier and an internal buffer. The decision IC operates at up to 12 Gb/s, using AlGaAs/GaAs HBTs with f/sub T/ of 40 GHz. A good sensitivity of 71 mV/sub p-p/ and a wide phase margin of 217 degrees at 11 Gb/s is also achieved under error-free conditions (less than 10/sup -9/ errors).<
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