One of the most popular applications for the ADuC7020 parts is in the area of Optical Networking where the device is part of a transceiver module that also contains a diagnostic interface that provides performance information on the optical data link. Typically these modules report in real-time the following: the received optical power, the transmitted optical power, the laser bias current, the transceiver input voltage, and the transceiver temperature. Shown here is an example of a reference design incorporating the ADuC7020. In this device, the average power and extinction ratio of the LDD, or laser diode driver, are controlled and monitored by the precision analog microcontroller. To maximize the bandwidth available in an optical system there is a requirement to have strict control and monitoring of a number of parameters such as temperature, average laser power, and extinction ratio. Recent MSAs such as SFF-8472 and XFP formally addressed this by setting out a specification for diagnostic monitoring via a two wire I²C interface. The ADuC7020 is seen by a host network controller as an EEPROM which is accessed via an I²C interface. The host controller can then read the diagnostic information from specific locations in memory on the ADuC7020. This design uses a chipset of ADI components. The ADN2890 and ADN2870 are SFF-8472 compliant limiting amplifiers and laser diode drives respectively. These are also available in space saving CSP packages minimizing the total area consumed by the chipset.