Patent ID: 6621649
Filing Date: 2003-09-16
Classification: G11B

Abstract:
A preamplifier circuit, comprising:a plurality of amplifier stages coupled together and operable to consecutively amplify a signal associated with a head of a hard disk drive; a power delivery circuit operably coupled to the amplifier stages and operable to provide power to the amplifier stages in a substantially concurrent manner when the hard disk drive is transitioning from a write state to a read state; and a control circuit operably coupled to the amplifier stages, and operable to activate at least two of the plurality of amplifier stages in a generally consecutive manner after the providing of power to the amplifier stages, thereby preventing a saturation of an output of the preamplifier circuit by preventing substantially a propagation of glitches through the preamplifier circuit and providing for a substantially fast write-to-read transition time wherein the control circuit is operable to open a previously closed first switch across a differential input of a first amplifier stage of the plurality of amplifier stages after the power delivery circuit has provided power to the plurality of amplifier stages, wherein the control circuit is further operable to open a previously closed second switch coupled across a differential output of a third amplifier stage a predetermined amount of time after the opening of the first switch, and wherein the control circuit is further operable to open a previously closed third switch coupled across a differential output of a fourth amplifier stage a predetermined amount of time after the opening of the second switch.