Fiber-Optic Chipset's "Eyes" Have It

Highly favorable "eye" patterns are said to be generated by the SY88900 Series of fiber-optic ICs. The three-chip set is for use in 1.25-Gbps Ethernet systems, 532-Mbps and 1062-Mbps Fibre Channel applications, and 622-Mbps SONET links. The set consists of the SY88902 laser-diode driver, the SY88903 limiting post-amplifier, and the SY88905 laser-diode controller. The driver provides separate modulation control and separate output enable for laser safety. It includes complementary open-collector outputs that drive peak currents of 25 mA. The low-noise limiting post-amplifier delivers chatter-free loss-of-signal (LOS) generation, as well as high gain and wide bandwidth. Delivering dc bias currents that are adjustable to 25 mA, the laser-diode controller also provides buffered LOS output when used with the post-amplifier IC. It's designed for fast, accurate diode calibration.