HFAN-02.3.3: Optimizing the Resolution of Laser Driver Current Settings Using a Linear Digital Potentiometer


Digital potentiometers are well accepted in fiber optic module manufacturing for setting the transmitter's application dependent variables, such as average optical transmit power and extinction ratio. This application note provides guidelines for optimizing the current setting resolution for the MAX3735 (2.7Gbps SFP laser driver), when interfaced with the DS1858 SFF-8472 digital diagnostic monitoring device.