A general-purpose driver for spindle motors in rigid disk drive applications

Over the past few years, disk drive capacities and performance have changed for the better in a dramatic fashion. While disk drives in personal computers only a few years ago had capacities of a few hundred megabytes, storage capacities of an order of magnitude greater are increasingly commonplace. The disk drive essentially consists of one or more disks which store the data, spinning at a high rotational speed, usually of the order of a few thousand revolutions minute (RPM). An actuator which supports suspension for the data accessing heads moves over the data surfaces of the disk(s) and transfers data to and from the other parts of a computer. Since, based on capacity, the number of data disks can vary from one to ten (or even higher), and the rotational speed can vary over a wide range, the spindle motors used in these disk drives can be of very different designs.