In order to provide a motor driving circuit in which a portion corresponding to a failed phase can be separated while miniaturization and lower costs are achieved, a motor driving circuit for driving a motor includes: a second driver circuit for driving a driver circuit which supplies a drive current corresponding to one phase of a multiphase motor having three or more phases, to the multiphase motor; and an electrical circuit which includes a plurality of electrical components and switches a connecting relation between the electrical components according to an operation mode designated from outside the motor driving circuit, thereby providing a circuit function corresponding to the operation mode.