A magnetic sensor integrated circuit, a motor and an application apparatus. The magnetic sensor includes a magnetic sensor, a signal processing unit, an output control circuit and an output port. The magnetic sensor receives a constant current sense a magnetic polarity of an external magnetic field and output a differential signal. The signal processing unit amplifies the differential signal and eliminates an offset of the differential signal to obtain a magnetic field detection signal. The output control circuit control, at least based on the magnetic field detection signal, the magnetic sensor integrated circuit to operate in at least one a first state in which a current flows from the output port to the outside and a second state in which a current flows from the outside into the output port.