An electrically operated actuator (10) for a slideable door (8) of a motor vehicle (6) includes a planetary gear set (12) having a sun gear (22), a number of pinion gears (24) rotatably mounted on a planet carrier (26) and interengaging with the sun gear, and a ring gear (28) interengaging with the pinion gears, the sun gear, planet carrier and ring gear being rotatable about an axis (A). An electrical motor (14) is connected to the ring gear to rotate the ring gear about the axis and an electrically actuated brake (16) is connected to the sun gear to brake rotation of the sun gear about the axis. A cable drum (18) is rotatably driven by the planet carrier (26). A cable (20) is wound around the cable drum and connected to the slidable door.