Constant current driving apparatus and constant current driving semiconductor integrated circuit

摘要

An object of the present invention is to drive a lot of loads by using a plurality of constant current driver ICs in a state of small variations in output currents among the constant current driver ICs. In order to drive a plurality of organic EL devices of an EL display panel 50 at constant currents, two or more constant current driver ICs are used. In the individual constant current driver ICs, a constant current driver circuit and a control circuit are embedded. In the first constant current driver IC, a reference current generating circuit is further embedded to derive a reference output current generated on a reference resistance from a reference output terminal. A reference output current from the reference current generating circuit is inputted to a reference current input terminal of each constant current driver IC to output the same current value of driving currents from a plurality of driving output terminals each. The driving currents are on-off-controlled by the control circuits.