Bipolar high-gain limiting amplifier IC for optical-fiber receivers operating up to 4 Gbit/s

A monolithic integrated high-gain limiting amplifier for future optical-fiber receivers is described. It is characterized by the following features: high insertion-voltage gain (maximum 54 dB); high input dynamic range (about 52 dB) at constant output-voltage swing (400 mV/SUB p-p/); high operating speed (up to at least 4 Gb/s); low power dissipation (350 mW at 50-Ω load); standard supply voltage (5 V); 50-Ω output buffer; one-chip solution; and small fabrication costs by use of a 2-μm standard bipolar technology without needing polysilicon self-aligning processes. The good values of operating speed and power consumption, which the authors believe has until now not nearly been achieved by other comparable bipolar amplifier ICs, are a result of careful circuit design and optimization. The amplifier was extended to a high-sensitivity (amplitude and time) decision circuit operating at up to 4.0 Gb/s by adding a high-speed master-slave D-flip-flop IC fabricated with the same technology.