Driving device and electric power steering apparatus using the same

A driving device comprising:

• a rotary electric machine including a stator on which motor windings of “n” systems (“n” is integer equal to or larger than 2), a rotor provided rotatably relative to the stator, and a shaft rotatable with the rotor;
• a substrate provided on one end side in an axial direction of the rotary electrical machine;
• a magnetic detection element mounted on the substrate for detecting a rotating magnetic field of a detection target which rotates integrally with the shaft;
• switching elements mounted on the substrate for switching energization of the motor windings;
• a lead wire set connecting the substrate and each phase winding of the motor windings;
• a power supply terminal connecting the substrate and a power supply;
• a ground terminal connecting the substrate and a ground;
• and
• a control circuit unit used to control on-off operations of the switching elements, wherein:
• the switching elements, the lead wire set, a power terminal including the power supply terminal and the ground terminal, and the control circuit unit are provided for each system;
• the switching elements, the lead wire set and the power terminal are arranged collectively in a power region provided for each system;
• and
• the lead wire sets are arranged in rotational symmetry.