NTC type resistor-based semiconductor laser adjustable constant-current driving circuit

The invention belongs to the laser control technical field and relates to an adjustable constant-current driving circuit, in particular to an NTC type resistor-based semiconductor laser adjustable constant-current driving circuit. The circuit includes an operational amplifier U10, an MOS tube Q19 and a laser LD which are connected with one another sequentially; the forward input end of the operational amplifier U10 is connected with a power source input end through a resistor R3; two ends of the resistor R3 are connected in parallel with a negative temperature coefficient NTC type thermistor R2; and the thermistor R2 is located on the heat dissipation housing of the laser LD. With the NTC type resistor-based semiconductor laser adjustable constant-current driving circuit of the present invention adopted, a normal constant current mode can be improved in that the instability of the output of a laser caused by the influence of a temperature factor can be eliminated; and the circuit is simple in structure and co