Patent ID: 7542031

Claim:
A current supply device comprising: a plurality of the current supply circuits, the plurality of the current supply circuits comprising: a plurality of current output circuits for respectively supplying current signals to targets to be driven; one or more monitor current output circuits for outputting monitor current signals; and a current adjusting circuit for collectively adjusting gains of the one or more monitor current output circuits and the plurality of current output circuits, the current adjusting circuit supplying an adjusted reference voltage to the plurality of current output circuits and the one or more monitor current output circuits, and each of the current output circuits including: a plurality of current sources for respectively outputting currents based on the reference voltage; and selection output means for selecting the respective currents output from the plurality of current sources, based on input data, and for synthesizing the selected currents to output them; and control means for controlling the current adjusting circuits of the plurality of current supply circuits such that the values of the plurality of monitor current signals are close to each other, based on the plurality of monitor current signals output from the plurality of current supply circuits, wherein the control means has a plurality of conversion means each converting each of the monitor current signals into a digital signal to output it as monitor data, and controls the current adjusting circuits of the plurality of current supply circuits such that the values of the plurality of monitor current signals are close to each other, based on the respective monitor data output from the plurality of conversion means.