Low-noise, high-gain Si-bipolar preamplifiers for 10 Gb/s optical-fiber links-design and realization

Design principles and circuit configurations of Si-bipolar transimpedance preamplifiers for 10 Gb/s optical-fiber links are discussed. The target specifications of the amplifier are near the limit achievable by the available technology. Therefore, the different amplifier stages had to be carefully optimized with respect to both flat magnitude and constant group delay of the total transimpedance up to about 7.5 GHz. Two different versions of preamplifiers were fabricated in an advanced production technology (f/sub T//spl ap/23 GHz). High transimpedance (710 /spl Omega/) and low equivalent input noise current density (averaged: /spl ap/9 pA//spl radic/(Hz)) were achieved.