Patent ID: 7580011

Claim:
A current generation supply circuit which supplies drive currents corresponding to digital signals for a plurality of loads comprising: a current generation circuit which supplies output currents to each of the plurality of loads as the drive currents, the current generation circuit comprising: a reference voltage generation circuit which includes a plurality of reference current transistors having transistor sizes different from each other, wherein at least a reference current having a constant current value is supplied and the reference voltage generation circuit generates a plurality of reference voltages having different voltage values based on the reference current to each of the plurality of loads; a drive current generation circuit which generates the output currents having a ratio of current values corresponding to the digital signals relative to the reference current based on the reference voltages; and a characteristic control circuit which includes a changeover switch that selectively flows the reference current to one of the plurality of reference current transistors and which sets the ratio of the output currents relative to the reference current in a plurality of stages by the changeover switch.