To provide a motor drive technique which can prevent abnormal heat generation of a motor due to soldering defects in a motor protective circuit.

A soldering defect detection motor protective circuit 11 detects the presence of abnormality of input signals, when the input signals of excitation signals and A-phase and B-phase signals outputted from a motor control section 10 are inputted. When there is an abnormality, the level of a part of the input signals is changed and outputted; when there is no abnormality, the input signals are outputted without changing the level. The excitation signals, a part of output signals, are inputted as a feedback to the soldering defect detection motor protective circuit 11. This soldering defect detection motor protective circuit 11 detects the presence of abnormality in the output signals. When there is abnormality, the level of a part of the input signals is changed and outputted; and when there is no abnormality, the input signals are outputted without changing of the level.