Semiconductor laser driving circuit and semiconductor laser device

摘要

There is provided an input circuit including a current/current conversion circuit and a current change-over circuit for converting an input control current into an inside control current; a control amplification circuit for amplifying a voltage corresponding to a difference current between an output current from the input circuit and a monitor current which is fed back from the photodetector for detecting a light output of the LD; an output circuit which is controlled with an output from the control amplification circuit; an offset compensation circuit for compensating for the offset generated between the input of the current/current conversion circuit and the output of the control amplification circuit, so that the offset is detected to compensate for the offset in the state in which the output of the control amplification circuit is cut off with the switch.