A 2 x 80 GBaud PAM-4 Analog Multiplexer With 2.4 Vpp Differential Output Voltage Swing

A 4:2 analog multiplexer (AMUX) for optical transmitters is presented, which can generate 80 GBaud(160 Gb/s) four-level pulse-amplitude modulation (PAM-4) signals with 2.4-V pp differential voltage swing at each output channel. The AMUX contains two 2:1 AMUX cells with fully differential configurations, and each AMUX cell consists of a clock input buffer, two data input buffers, an AMUX core, and an output buffer. The 1.2 x 2.42 mm
²
AMUX chip was designed in 90-nm BiCMOS technology with 300/360 GHz f
T
/f
MAX
SiGe heterojunction bipolar transistors (HBTs) and consumes 2.74 W from 3.3V, 5 V, and 6 V supplies.