A 10 Gbit/s (STM-64, OC-192) 1:4 demultiplexer (DEMUX) with 4-phase clock wasachieved in TSMC's standard 0.25 μm complementary metal-oxide-semiconductor (CMOS) technique. Allof the circuits are in source coupled FET logic (SCFL) to achieve as high as possible speed andsuppress common mode distortions. This DEMUX is featured by constant-delay buffers to generate a4-phase clock and adjust skews of the four channel outputs. The fabricated DEMUX operates error freeat 10 Gbit/s by 2^(31) -1 pseudorandom bit sequences (PRBS) via on-wafer testing. The measured rootmean square (rms) jitter, rising and failing edge of the eye-diagram are 11, 123 and 137 ps,respectively. The chip size is 0.9 mm x 1.2 mm and the power dissipation is 550 mW with a 3. 3 Vsupply.
Using native CMOS technology,EDA tool,and adopting full-custom design methodology,a laser diode driver for the use of STM-1 and STM-4 optical access network,is realized by CSMC-HJ 0.6μm CMOS technology to modulate laser diodes at 155Mb/s (STM-1),622Mb/s (STM-4) with adjustable modulation current from 0 to 50mA for an equivalent 50Ω load.The maximum modulation voltage is over 2.5V pp corresponding to a 3V DC bias for output stage.The time range of rise and fall from 360ps to 471ps is measured from the output voltage pulse.The RMS jitter is no more than 30ps for four bit rates.The power consumption is less than 410mW under a power supply voltage of 5V.According to the experimental results,the laser diode driver achieves the same level as their counterparts worldwide.
