Patent ID: 6320890
Filing Date: 2001-11-20
Classification: H01S,H03F,H03G

Abstract:
A laser driving circuit comprising:a first amplifier for comparing an input signal which controls a light emission intensity of a semiconductor laser with a monitor signal obtained by monitoring a driving current of the semiconductor laser and effecting the control operation to make the input signal and the monitor signal substantially equal to each other;a second amplifier connected to an output terminal of said first amplifier;an adder circuit for adding together output signals of said first and second amplifiers;a driving current generating circuit having an input terminal supplied with an output signal of said adder circuit and an output terminal configured to be connected to the semiconductor laser, for generating a driving current of the semiconductor laser according to the output signal of said adder circuit; anda terminal to which a resistor for detecting the driving current output from said driving current generating circuit and generating the monitor signal is connected.