The M61880FP is a semiconductor laser-diode driver/ controller. Its functions are the driving and laser power control of a specific type(Mitsubishi's N-type laser)of semiconductor laser diode,in which the anode of a semiconductor laser diode is connected in stem structure to the cathode of a monitoring photodiode. The IC has a laser drive current output pin of sink type and is capable of driving a laser diode on a maximum bias current of 40mA and a maximum switching current of 100 mA,which is switching at a rate of 200Mbps. Since the M61880FP has a built in sample-hold circuit,it is possible to realize an internal APC* system that requires no external device for laser power control. *:Automatic Power Control