3.3/5V Multi-rate Laser Diode Driver and Limiting Amplifier for Optical Transceivers

A laser diode driver and a limiting amplifier for multirate and multistandard optical transceiver modules from 155Mb/s to 2.1Gb/s had been developed using a 0.5-mum SiGe BiCMOS technology. With new driving circuit, the laser can be DC-coupled to the laser diode driver for reduced component count and ease of multi-rate operation. Automatic power control (APC), modulation compensation and built-in temperature-compensation are also achieved. Careful circuit design enables the limiting amplifier to realize better input sensitivity of 2mVp-p and provides approximately 50dB of gain. A novel received signal strength indicator (RSSI) circuit is proposed to accomplish the input signal-detect function, and the circuit complexity and current consumption can be reduced. A low-frequency feedback loop is integrated in the limiting amplifier to reduce input offset, making it below 100muV typically