Patent ID: 6490120
Filing Date: 2002-12-03
Classification: G11B

Abstract:
A disc drive, comprising:a head adjacent a recording surface of a rotatable disc; a voice coil motor coupled to the head; and a servo circuit which applies current to the voice coil motor to controllably position the head with respect to the recording surface, the servo circuit comprising a servo processor utilizing an internal gain to control a magnitude of the current, the gain optimized by the servo processor executing steps of: (a) selecting an initial value of gain for the internal gain; and (b) performing a gain convergence operation comprising repeatedly positioning the head and accumulating position error a successive number of passes to iteratively converge the internal gain from the initial value of gain to a final value of gain which provides optimal performance by the servo circuit, the gain convergence operation utilizing a scale factor during each of the successive number of passes, the scale factor iteratively converging over the successive number of passes from an initial value to a final, nominal value.