A semiconductor device driving a current load device includes a constant current circuit with six V-I conversion circuit blocks, each including current mirror and V-I conversion circuits and output a current different from a current from other V-I conversion circuit blocks. In the current mirror, first and second transistor sources are connected to a power source. Gates of first and second transistors are connected to a the first transistor drain. The second transistor source is an output. In the VI conversion circuit, a current control voltage is input into a non-inversion input of an operational amplifier, an inversion input of the operational amplifier connects to one terminal of a variable resistor with the other grounded. An output of the operational amplifier is connected to the third transistor gate. The third transistor drain is connected to the first transistor drain. The source is connected to one terminal of the variable resistor.