1.25 Gb/s low power CMOS limiting amplifier for optical receiver

In this paper, we report a limiting amplifier (LA) for optical access networks (OAN) and gigabit Ethernet (GbE). Active inductors are employed as loads to expand the bandwidth and to get stable DC operating points. Omitting source followers (SK); the modified direct-coupled technique is used to reduce power dissipation. This LA exhibits an input dynamic range of 40 dB (5-500 mV_p-p), and an approximately constant single-ended output voltage swing of 280 mV_p-p over a 50 Ω load. It consumes a DC power of only 130 mW under a single 5 V supply. The realized LA can operate well at standard bit rates of 155 Mb/s, 622 Mb/s and 1.25 Gb/s.