An electric motor has a stator and an external rotor (40). Its external rotor (40) has a sensor magnet (54) having a plurality SP of sensor poles (55). The motor also has: at least one rotor position sensor (42, 44) for generating a rotor position signal and a rotor position evaluation arrangement for generating an absolute value for the rotor position, which apparatus comprises an A/D converter (144) having a resolution of at least two bits, the at least one rotor position sensor (42, 44) being connected to the A/D converter. In order to enable obtaining different digital values, even at rotational positions within the angle range of one sensor pole, each analog rotor position sensor signal is converted by the A/D converter into a digital value having at least two bits.
