Patent ID: 8630054

Claim:
A data storage system comprising: a disk; a head; a spindle motor for rotating the disk, the spindle motor comprising a plurality of windings and a rotor rotatable at a variable spin rate wherein the rotor generates a back EMF (BEMF) voltage across the windings proportional to the spin rate of the rotor; a plurality of switching elements coupled to the windings; switch control logic for generating switch control signals applied to the switching elements for generating an internal supply voltage from the BEMF during a spin down mode, the internal supply voltage enabling a controller to execute data programming operations for writing data from volatile memory to solid-state non-volatile memory in an event of a power interruption to the data storage system; and a demand regulation circuit configured to provide a throttle signal to the controller in response to detecting that the internal supply voltage has fallen below a first predetermined level; wherein the throttle signal causes the controller to lengthen delay periods between program cycles for the data programming operations to the solid-state non-volatile memory.