A CMOS burst-mode up-stream transmitter for fiber-optic gigabit ethernet applications

A fully integrated fiber-optic transmitter chip for gigabit Ethernet applications has been implemented in a CMOS technology. For controlling the transmitted optical power so to obtain reliable and constant averaged optical power, the transmitter proposed in this paper uses separated bias and modulation currents control circuits based on the feedback from the monitoring photo-diode (MPD). The chip was fabricated in a mixed-signal analog CMOS technology with 0.18mum gate length and measurements were implemented in a chip-on-board configuration (COB) using pig-tailed FP laser. Under the burst-mode operation of 1.25Gb/s PRBS, measurements show about 0.5dBm transmitted optical power with above 11dB extinction ratio over a wide temperature range. Based on the measurements, this work complies with the EPON IEEE P802.ah standard