An integrated 1.25 Gbit/s laser driver/post amplifer IC

This paper presents the first reported integrated 1.25 Gbit/s post amplifier and laser driver, to the authors knowledge. The post amplifier amplifies 20 mV signals from a pre-amplifier and provides redundant loss of signal detectors. The laser driver provides up to 100 mA DC drive and 25 mA/sub p-p/ C drive. This presents a large on chip isolation challenge and 79 dB of isolation was achieved. The chip has sufficient redundancy and error detection to provide international Class 1 laser safety certification. The chip operated up to 1.6 Gb/s. The design is implemented in a 0.45 um L/sub eff/ BiCMOS technology with 12 GHz NPN's. It is packaged in a 48 lead 7 mm plastic quad flat pack surface mount package.