Browse Prior Art Database

Read Preamplifier for a Magnetic Head

IP.com Disclosure Number: IPCOM000051862D
Original Publication Date: 1981-Mar-01
Included in the Prior Art Database: 2005-Feb-11
Document File: 2 page(s) / 34K

Publishing Venue

IBM

Related People

Lewkowicz, J: AUTHOR [+2]

Abstract

The figure illustrates a preamplifier especially adapted for biasing a magnetic head. The amplifier provides DC biasing and regulation for the head. minimizes output offset of the preamplifier, and provides the desired transfer functions for the read signal. The voltage regulator VR compares the head common mode bias voltage EB with the reference voltage ER and regulates the supply of voltage ES. From ES the preamplifier PA produces a common mode output voltage VC. The feedback amplifier FA amplifies VC and produces a feedback signal which acts as the bias voltage EB.

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Read Preamplifier for a Magnetic Head

The figure illustrates a preamplifier especially adapted for biasing a magnetic head. The amplifier provides DC biasing and regulation for the head. minimizes output offset of the preamplifier, and provides the desired transfer functions for the read signal. The voltage regulator VR compares the head common mode bias voltage EB with the reference voltage ER and regulates the supply of voltage ES. From ES the preamplifier PA produces a common mode output voltage VC. The feedback amplifier FA amplifies VC and produces a feedback signal which acts as the bias voltage EB.

The preamplifier also amplifies the differential voltage VM from the head and produces the differential output voltage V0. The open loop differential gain of the feedback amplifier is A(1) = - K(1) omega(1) over s + omega(1) (1) A(2) = K(2) omega(2) over s + omega(2) (2)

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