WRITE-TO READ SWITCHING IMPROVEMENT FOR DIFFERENTIAL PREAMPLIFIER CIRCUITS IN HARD DISK DRIVE SYSTEMS

摘要

PURPOSE: Write-to read switching improvement for differential preamplifier circuits in hard disk drive systems is provided to prevent saturation of an output of a preamplifier circuit by preventing a propagation of glitches through the preamplifier circuit and providing a fast write-to-read transition time. CONSTITUTION: A preamplifier circuit(150) comprises a plurality of amplifier stages(102,104,106,108) 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(152) 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. Preventing substantially a propagation of glitches through the preamplifier circuit and providing a substantially fast write-to-read transition time prevent a saturation of an output of the preamplifier circuit.