Microchip MIC3003GFL

FOM Controller with Internal Calibration

The MIC3003 enables the implementation of sophisticated, hot-pluggable fiber optic transceivers with intelligent laser control and an internally calibrated digital diagnostic monitoring interface per SFF-8472. It essentially integrates all non-data path functions of an SFP transceiver into a tiny (4mm x 4mm) QFN package. A highly-configurable automatic power control (APC) circuit controls laser bias. Bias and modulation are temperature compensated using dual DACs, an on-chip temperature sensor, and NVRAM look-up tables. A programmable internal feedback resistor provides unprecedented dynamic range for APC. Controlled laser turn-on facilitates hot plugging. An analog-to-digital converter converts the measured temperature, voltage, bias current, transmit power, and received power from analog to digital. An EEPOT provides front-end adjustment of RX power. Each parameter is compared against user-programmed warning and alarm thresholds. Analog comparators and DACs provide high-speed monitoring of received power and critical laser operating parameters. Data can be reported as either internally calibrated or externally calibrated. An interrupt output, power-on hour meter, and data-ready bits add user friendliness beyond SFF-8472. The interrupt output and data-ready bits reduce overhead in the host system. The power-on hour meter logs operating hours using an internal real-time clock and stores the result in NVRAM. In addition to the features listed above which are already implemented in the previous MIC300x controllers, the MIC3003 features an extended temperature range, options

to mask alarms and warnings interrupt and TXFAULT, a reset signal source, and the ability to support up to four chips with the same address on the serial interface. It also supports eight-byte SMBus block writes. Communication with the MIC3003 is via an industry standard 2-wire SMBus serial interface. Nonvolatile memory is provided for serial ID, configuration, and separate OEM and user scratchpad spaces.