A 12-channel data-format-free 1 Gb/s/ch parallel optical receiver

Data-format-free operation is required for a multi-channel optical receiver array used in parallel optical links. A fixed decision threshold level scheme was applied to achieve a data-format-free receiver. However, it requires extremely high bandwidth, compared with the clock frequency for receivers, to obtain a large dynamic range and a wide eye opening, and to tolerate interchannel skew caused in optical fibers. Therefore, it seems to be difficult to achieve Gb/s class throughput with this scheme using low-cost technology. Using a decoder with AC receivers is one solution for obtaining data-format-free operation at narrower bandwidth, but this increases power dissipation. The receiver chip enables attainment of a Gb/s class data-format-free parallel optical receiver module suited for low cost packaging technologies with lower power consumption by utilizing automatic decision threshold control (ATC) which achieves response in one bit.