Laser driver/limiting amplifier + DDMI controller and APD DC-DC controller
The M02076/7 is a low power, highly integrated, laser driver with limiting amplifier intended for SFF and SFP module applications to 3.1 Gbps. An internal state machine and EEPROM perform all functions necessary for standalone operation (EEPROM is internal in the M02077 and an external EEPROM may be used with the M02076). The internal state machine also acquires and scales all the necessary monitoring parameters in real time and makes them available to an external host controller. The EEPROM allows the M02076/7 to be re-calibrated multiple times and operate either standalone, under the control of an external microcontroller or under the control of a SFF-8472 Host controller. All optical component calibration information is stored in EEPROM and no external microcontroller is needed on a module. An analog passthru mode allows direct access to the EEPROM during module assembly and calibration. Use of the M02076/7 will minimize power consumption, parts count, provide design flexibility and simplify manufacturing processes. The laser driver can be configured to control the laser with either open loop look-up tables or one of three different closed loop methods using monitor photodiode feedback (including the Mindspeed proprietary Dual Closed Loop mode). The M02076/7 limiting amplifier inputs have selectable bandwidth and selectable output swing. The input sensitivity is better than 5 mV at 1.25 Gbps and 6 mV at 3.1 Gbps and the LOS thresholds are programmable using an internal DAC.