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Servo Power Chopping by Mode Switch between Wake-up and Idle without Dedicated Control Line

IP.com Disclosure Number: IPCOM000010431D
Original Publication Date: 2002-Nov-29
Included in the Prior Art Database: 2002-Nov-29
Document File: 2 page(s) / 20K

Publishing Venue

IBM

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Invention Disclosure Publication for JP8-2002-0413

Created By Akihiko Nadaguchi On 2002/08/28 11:34:24

Last Modified By Chieko Kobayashi On 2002/11/29 15:11:46

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Editors of this article Hiroaki H Suzuki/Japan/IBM, Hiroyuki Ono/Japan/IBM, Kenji X Kuroki/Japan/IBM, Hideo

                     Asano/Japan/IBM Status Published
Title Servo Power Chopping by Mode Switch between Wake-up and Idle without Dedicated Control Line Inventors Hiroaki H Suzuki, Hiroyuki Ono, Kenji X Kuroki, Hideo Asano
Attorney Akihiko Nadaguchi/Japan/IBM
Functional Area R80,R90 STD F/I, LSI, C/I
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Publication Information

Date Approved

Publication Name Research Disclosure

Date Sent 2002/11/29

Date Published 2003/01

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Servo Power Chopping by Mode Switch between Wake-up and Idle without Dedicated Control Line

Disclosed is HDD head amplifier IC chip, AE, servo power-chopping method (AE "wake-up" during servo read for lower power dissipation) without having control line from HDC, or without sending successive "wake-up" then "idle" command by servo areas. Recent AE has 3 modes, "wake-up" (or active), "idle" (or standby) and "sleep" modes, and has register bits (example: 2 bits) to control AE mode between "wake-up" and "idle" modes (in not "sleep" mode), between "wake-up" (or "idle") and "sleep" modes. For servo power-chipping operation, repeated mode change between "wake-up" and "idle" by servo period, is carried out, because "idle" to "wake-up" takes only several micro (E-6) seconds. On the other hand, "sleep" to "wake-up" (or "idle") takes several milli (E-3) seconds which cannot be used for servo power-chopping (too slow). In addition, almost 3 and 3.5inch HDD's AE has dedicated control line from HDC, to change mode between "wake-up" and "idle" directly by high/low state, together with control register bit existence, to make servo po...