An 80-Gb/s 231-1 pseudorandom binary sequence generator in SiGe BiCMOS technology

A 2³¹-1 pseudorandom binary sequence (PRBS) generator with adjustable output data rates up to 80 Gb/s is reported in a production 130-nm BiCMOS process with 150-GHz f_T SiGe heterojunction bipolar transistor (HBT). The pseudorandom sequence is generated at 20 Gb/s using a linear feedback shift register (FSR), which is then multiplexed up to 80 Gb/s with a 4:1 multiplexer. A BiCMOS logic family combining MOSFETs and SiGe HBTs on high-speed paths is employed throughout the PRBS generator to maximize building block switching speed. Adjustable delay cells are inserted into critical clock paths to improve timing margins throughout the system. The PRBS generator consumes 9.8 W from a 3.3-V supply and can deliver an output voltage swing of up to 430 mV single-ended at 80 Gb/s.