XFP Laser Control And Digital Diagnostic IC

The DS1862A is a closed-loop laser-driver control IC with built-in digital diagnostics designed for XFP MSA. The laser control function incorporates Automatic power control (APC) and allows extinction ratio control though a temperature-indexed lookup table (LUT). The DS1862A monitors up to seven Analog inputs, including temperature and monitor Diode (MD) current, which are used to regulate the laser bias current and extinction ratio. Warning and alarm thresholds CAN be pro- grammed to generate an interrupt if monitored signals exceed tolerance. Calibration is also provided internally using independent gain and offset scaling Registers for each of the monitored Analog signals. Settings such as programmed calibration data are stored in password- protected EEPROM memory. Programming is accom- plished through an I 2C-compatible Interface which CAN also be used to access diagnostic functionality. By Maxim Integrated Products