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Browse Prior Art Database

Hard Disk Drive Pre-Amplifier with Read Back Interface

IP.com Disclosure Number: IPCOM000119031D
Original Publication Date: 1997-Oct-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 4 page(s) / 74K

Publishing Venue

IBM

Related People

Matsubara, N: AUTHOR [+2]

Abstract

Disclosed is a new serial interface of a Hard Disk Drive (HDD) Pre-Amplifier with: 1) improved reliability and 2) reports back detail status to controller.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 55% of the total text.

Hard Disk Drive Pre-Amplifier with Read Back Interface

      Disclosed is a new serial interface of a Hard Disk Drive (HDD)
Pre-Amplifier with: 1) improved reliability and 2) reports back
detail status to controller.

      A Pre-Amplifier is a type of semiconductor circuit that handles
the following functions in the HDD:
  - Provides bias for MR-element of Read head
  - Amplifies very low-level high-speed signal from Read head
  - Drives Write head to record data on a magnetic media
  - Checks Errors

      On the recent high-performance HDD, many parameters (Head
Address, Write Current, Read Bias Current, etc.) have to be
critically controlled to have the best HDD performance.  The total
number of bits  to be applied to a Pre-Amplifier are exceeding 30
bits and it is not realistic to drive them parallel from the outside.
Serial interface is introduced to minimize Incoming and Outgoing
(I/O) lines between Pre-Amplifier and Controller (Figs. 1 and 2).

      To maintain data integrity, it is requested to minimize
transmission errors between the Controller and Pre-Amplifier.  For
instance, Electrostatic Discharge (ESD) from the human body is
injected into HDD and "Address Bit" of serial data bit are changed by
this spike,  an erroneous write is performed on the wrong head
location, and existing  user data will be lost.

      The Pre-Amplifier is mounted on the head side of the Flexible
Printed Circuit (FPC) and the controller is connected on the...