Optical receiver in deep-sub-micrometre CMOS with -28.2 dBm sensitivity at 1.25 Gbit/s

A transimpedance amplifier (TIA) as preamplifier for optical receivers in passive optical networks designed in a digital 120 nm CMOS technology is described. Varying the open-loop gain of the preamplifier by a factor of 340 is suggested as a solution for the stability problem of this variable gain TIA. Sensitivities of -29.9 dBm at 622 Mbit/s and -28.2 dBm at 1.25 Gbit/s with 1.3 (mu)m light and a bit error ratio of 10/sup -10/ are achieved.